m@Robertson

Create a Battery DIScharger

Letting an ebike battery sit and stew in a high state of charge accelerates its march to end-of-life. Here is a straightforward, albeit unusual way to help with that.

This short article is going to describe something you probably never thought you had any use for, and maybe still won’t. I read about them for years, but didn’t realize how handy they were until I finally took the plunge and put one together. This is one of those gadgets where you won’t really appreciate its utility until you have one available to take advantage of.

Here’s an example:
Just yesterday after a very long ride and recharge, I pulled my Bullitt out of the garage to do some basic maintenance. Rain was unexpectedly pending and set to last a few days. My 14S/52v pack was up to about 57.5v, which would have been fine if my planned daily ride was not cancelled, and the battery will now sit for a few days. So I plugged in my discharger, set it for 10 minutes and while I did some minor work on the bike, the discharger brought my pack down to 55.0v.

Whats The Problem?

Your typical ebike battery is called “lithium ion”, but in fact that term covers a variety of chemistry variations that behave differently. Ebikes typically use a variation known as “Li-NMC”, which translated means “Lithium Nickel-Manganese-Cobalt oxides”. If you charge up a Li-NMC battery and let it sit, doing so accelerates its march to the end of its lifespan.

In an ideal world, you never charge a Li-NMC battery up and let it sit. If you do, the battery isn’t going to die today, but it will happen sooner thanks to this.

How to make a lithium battery last, or…kill it, if you like

The article above is quite technical. Skip forward and start reading at the heading “Amount of TIME at HIGHER VOLTS is BAD”. Then go further down to the header that says “Don’t charge to 100%” and read that. Or take a bigger shortcut and just read the Conclusion section. Its worth noting this article was written in 2017, about a video lecture given in 2013… None of this is up for debate, or new news despite what you may hear from the self-appointed experts on your favorite internet forum.

Google Search: “How to make a Lithium ion battery last longer“

So… Extended time sitting charged up high is bad. Got it. I try and charge to full voltage only just before I ride. If I have a ride planned for the morning I charge most of the way the evening before. As soon as my alarm goes off in the morning I plug in my charger to top off while I perform my morning ablutions.

But what if something comes up and I can’t ride? Or I get lazy? Or whatever. Now I have a battery pumped up to 11 and its going to sit like that. It would be nice if I could back that battery voltage back down some.

To be perfectly clear, using this discharger concept (aka “cycling”) does put mileage on the battery. We won’t fix that. But this is the lesser of two evils. Better to plan charging better so you don’t do this at all. But we live in an imperfect world, so…

Time For The Solution

The key component of this gadget is for us to find a load we can place on our ebike’s battery, to drain it down to a more palatable level. There are a couple of ways to do that.

Method 1: The Cheap, Slow Way

Do something like hook up a string of light bulbs to your battery. Let them blaze away for awhile and slowly drain your power back down. The ones I have seen like this use a wooden plank and old-timey ceramic bare light bulb sockets.

A REALLY cheap way would be to get

an extension cord with multiple outlets, or a power strip
some plug in bulb sockets
some 48v low voltage camping light bulbs

Plug in the sockets into the extension cord, screw the bulbs into your little sockets and voila, you have a basic battery load (and off-grid campground light). Now… 48v bulbs only eat a very few watts, so this is going to be a pretty slow drain, but its cheap and it will work. And you can always add more sockets and bulbs.

Next, you want to address the issue of potentially draining the battery down too much. Going the cheap route, since the timer has to be wired into a gadget that is not plugged into a wall socket, I don’t have a fail-safe solution to recommend. However you could set a stopwatch timer on your cell phone, or a kitchen timer that you keep nearby, pay attention when the timer goes off and go manually disconnect the discharger.

What follows is the method I chose, which includes a built-in cutoff timer. You could include such a timer in a cheapo light-bulb-based solution no problem.

Method 2: The Fast/Convenient Way.

Use a Load Resistor. This method will take more effort to put together, and costs more, but will be a lot more convenient to use in everyday life.

Grin Technology makes a 6.8 Ohm, 400w load resistor designed specifically to soak up current from an ebike battery. A load resistor works by turning electrical current into heat. So these suckers get REALLY hot. How hot? Well, my 52v packs will heat one of these little buggers up to around 450-500 degrees, fahrenheit.

You want to be very thoughtful about what you set this unit on when you plug it in. That includes leaving free space around it, and ensuring no one will accidentally stumble upon, sit on or otherwise touch it.

I like to set mine on top of a brick, with the brick sitting on a concrete driveway or patio. I set one on a painted garage floor once and the grey paint on the garage floor burned a little bit brown from the heat. So a brick insulator is a really good, almost-free enhancement.

NOTE: This whole assembly is sitting on a concrete patio outdoors. NOT a shag rug or anything else remotely flammable.

Above you see the complete discharger. A Grin Technologies load resistor sitting on a brick, connected to a 60-minute timer, connected to a 6-foot or so cable, connected to a watt meter which finally has a connector that lets it attach directly to one of my batteries. Since much of this gadget is made up of various bits and pieces I had made up for other things, you see I had to use things like gender benders to get the connections right. The watt meter has a corrective note on its face letting me know how far off of true voltage it is, and what it needs to read so I have a true 55.4v (which is meant for low amperage charging and not much use when I am yanking 7.5a out of a battery on a discharger).

I made a relatively long cable to give myself the freedom to ensure the load resistor – which again will become dangerously hot and must be put in a safe-from-causing-a-fire place – is located safely away from everything and everyone when in use.

Using a 36v battery, this load resistor will drain the battery at a constant rate of about 5 amps. Connected to a 48v pack, it will drain the pack at a rate of 7 amps. My 52v packs pull about 7.5 amps. I have two of these load resistors, and a Y adapter that lets me plug them together in series for about a 15 amp draw. This is acceptable load for a big 52v battery, but I’ve found that in practice running two of them like that is too much of a good thing. It only takes twenty or so minutes for just a single unit to pull a volt or two out of even the biggest batteries and that is plenty fast.

This is a fairly heavy duty solution, and I used the heavy duty timer described here (a quick-finish 60-minute version) to limit the discharge time so the battery doesn’t drain down too far.

An additional article related to putting together one of these for yourself:

How To: Safe, Reliable Electrical Crimp Connections (part 1 of 2)

To Sum Up:

In an ideal world it is better to never need one of these discharger kajiggers. You’re better off riding the bike, and never charging the thing up high and letting it sit in the first place. But in real life things don’t always go as planned. Having a discharger on hand – regardless of whether you go all in or do it on the cheap – can be a handy way to do penance for the occasional sin.

Litelok X3 Review – From a Bike Owner’s Perspective

The angle-grinder-resistant Litelok X3 bicycle and motorcycle lock has been getting a lot of pre-release publicity. Here’s my take as an owner, not a professional trying to destroy one.

This Just In…

My Litelok X3 U-lock arrived from the UK a couple of days ago. These locks have been getting a LOT of publicity lately. It occurs to me so few have made it into the wild thus far, there isn’t much information from normal owners, versus professional reviewers who focus on what happens when they cut one up.

Dollar shown for scale. You will need 299 more of them to buy one of these bad boys.

Note to UK readers: we refer to D-locks as U-locks here in the USA, so I’ll stick with that.

You won’t see me using any angle grinders here, nor dynamite or filthy language. I bought the Litelok X3 – at normal retail pricing – to lock up a bike. There is plenty out there on how difficult the X3 is to attack, so I’ll skip all of that since its been done to death already.

Instead, I’ll look at the X3 from the perspective of what I saw for the first time when it came out of the box, how I plan to use it and how it compares to my other already-expensive U lock solutions.

I’ll also note why I bought it versus its chief competitor, the Hiplok D1000 (and why I didn’t wait for their upcoming DX1000). Finally, I’ll make some brief observations on the right way to maximize the utility of a lock like this.

What I Need To Protect

I have a Bullitt cargo bike I use as a daily driver. I lock it up outdoors all the time. My theft insurance requires I have the bike locked to a fixed object for coverage to apply, so for proof’s sake I take a picture every time I leave it locked up somewhere.

The Purchase Process

You buy it online at the Litelok web site. There is currently an order backlog. I saw reviews written as recently as a month ago stating the wait was two to three months. Litelok’s web site lists a 30-day wait. My lock arrived precisely 30 days after I purchased it in November 2023.

Viewing the web site, there doesn’t appear to be a difference between the bicycle and motorcycle version. There was no material stated difference on the web site at the time of purchase, but today the moto version does list -40°C freezing-spray resistance. I have to wonder if the bicycle version doesn’t have that as well since that version’s web page now indicates it is certified for both Sold Secure Motorcycle Diamond and the less-stringent Bicycle Diamond ratings. Either way, for US$300 I wanted to take no chances on having the most-capable version of this lock, so I bought the moto variant.

Internal Dimensions

In addition to the professional lock-destroyer reviews, what sold me were its internal dimensions of 100mm in width (3.93″) and 195mm (7.6″) in length. I wanted state-of-the-art angle grinder resistance, but practicality is required. It has to fit around stuff.

This is where the Hiplok D1000, which is the only real competing product on the market now, effectively fell out of consideration. The Hiplok’s internal dimensions are 92mm (3.6″) by 155mm (6.1″). Thats acceptable, widthwise, but pretty short on the length. The tapered angled shape of the outer loop of the shackle further constricts its usability (more on why this was considered a dealbreaker in the Usage section below).

I didn’t want to risk $300 and find out I was unable to use it everywhere I wanted to. I considered waiting for the spring 2024 release of the Hiplok DX1000, but its increased size (112mm x 205mm, which is quite large) is maybe too much of a good thing. The X3 gives me enough to do the job I want.

Weight

The X3 weighs 2.1 kg (4.6 lbs), which is damn heavy. The Hiplok DX1000 (the bigger one) weighs 2.6 kg, or 5.7 pounds. Holy cow. So the bigger Hiplok with the more usable size is both bigger than I need and the weight is more than a pound heavier. Another knock against it as a practical choice.

Don’t take away a negative impression of the Hiploks from what I’m saying here. Both the D1000 and DX1000 seem like great locks, but when I look at my own needs, both versions come in second place in size, weight and in the case of the larger DX, price. Your own needs may flip to a different conclusion.

Convenience?

Given the weight I just listed, the X3 might seem impractical for all but XXL solutions. However, its a compact package designed to be tight and rattle-free.

If you have a sturdy pannier, a rack with a cargo net or a backpack, this lock is heavy, but not too big to carry along. Besides, the weight of the X3 is the price you pay for angle-grinder resistance. If you want light weight, kiss goodbye this feature, which is the whole reason you’d buy this lock in the first place.

The X3 certainly presents itself as a quality piece of kit that is easy to use and clearly made very well.

One of the Litelok X3’s jobs is to replace my disc brake lock for quickee lockups. It is unobtrusive enough I found out the hard way I need a reminder cable so I don’t try to roll the bike away with it still attached.

An Unexpected, Pleasant Surprise

The pick-resistant Abloy locking mechanism is far less fiddly with regard to key insertion, rotation and removal than any of my other higher-quality, pick-resistant locks. For those locks they seem to commonly need a retry or three to get the key in there just right, fully inserted, rotated to lock, unlock and then withdraw. They all work but it doesn’t seem to ever be a smooth process. This is something so common I gave it no thought until I had been using the X3 for awhile and realized it doesn’t have this issue. Look at the shortie videos showing the use of the X3 below. I didn’t intend to showcase the ease of using the key mechanism, but watch for it and its right there to see.

Since I lock frequently, often multiple times per day, this seemingly minor bit of convenience stands out.

Shackle Dimensions

The X3’s shackle is not round, its oblong. 24mm on the narrow axis and 26mm on the wide one. So it won’t fit inside the links of most chains.

You can forget about fitting the X3 thru a link in an 11mm boron steel chain. With 18mm and 16mm shackles – which are BIG as such things go – my other two U-locks fit right through.

I also have a 13mm boron-steel long-link chain. The X3 could be pushed inside of it on the narrow axis, with a very mild effort. It did dent the exterior of the X3 very slightly when I pulled on the chain. This is not something I’d want to be doing regularly. Notice in the picture below the fit was snug enough the X3 shackle stood upright. The best locking scheme is quick and easy. This tight fit ain’t that.

I don’t carry around my 2-meter, 13mm chain as thats too big even for me.

Price

Its three hundred bucks. Plus shipping. And tax. However its price versus its only competitor is the same. The larger Hiplok DX1000 costs an extra US$50 – and is not going to be available for months.

Usage

For me, the X3 – or any armored angle-grinder-resistant lock – is best used as a standalone in a multi-layered locking scheme. Don’t use it such that it can be bypassed by cutting your chain instead. When used on the bike, that bike is effectively never going to be rolled anywhere by anyone except the owner.

So how am I using it? I presently have a total of four security devices (two U-locks, a chain and a little disc lock) used in two different locking solutions. Those solutions are…

The Quickee

For low-security stops where it stays visible to me at all times, I use a simple Kryptonite disc brake lock, which does a great job for what it is: Small, lightweight, easy to deploy and remove.

The X3 is going to replace that lock completely. I will still use the little Kryptonite on a different bike. It will probably go into the handlebar bag on the Apostate. But for the white Bullitt, I get so much security from this literally 10-second lockup with the X3, it would be crazy not to take advantage of it.

The Whole Enchilada

My locking scheme for all other situations has two layers, uses two independent U-locks and a noose chain. The chain is noosed to the bike frame’s seat tube and rear wheel. It runs forward where my biggest U-lock secures it and the bike to a stationary object. Ideally, that big U-lock locks around the front wheel rather than just letting the chain pass thru it, so cutting away just the chain does not release the front wheel.

A second locking layer is a U-lock that independently wraps around the frame’s seat tube and rear wheel, so if the front U and chain are defeated, the bike still has to be carried unless you also cut away that second lock.

Since we are talking about a bike that is about 8 feet long and weighs quite a bit, the risk of two or more people carrying it off is minimal. That second U-lock in conjunction with the first, and the chain, should visually send the signal that its easier to steal a nearby car than this bike.

The X3 is going to become the second, independent U-lock. Since the X3’s shackle is so thick, my 11mm chain is not usable with it. HOWEVER, since I have a noose chain, the noose end has a great big loop on the end that WILL fit, should I need a little more chain to reach a little further out.

But never mind the chain… the anti-twist feature on the X3’s shackle means you need two cuts to get the lock off the frame… and considering how much time I spend inside of a bank or a grocery store… that lock is not going to be defeated in time.

Even doing it the long way, locking up the bike is a sub-2-minute process (Usually I noose the chain to the seat tube of the bike and that takes up several inches of slack in the chain).

The X3 fits right into what is, as you can see, a process that is quick and convenient.

Ideal Use?

This is my opinion and you are free to disagree: The Litelok X3 is not best employed as a device that locks your bike to something. U-locks in general can’t reach very far, and despite the X3 being twist-resistant, it is not twist-proof. I have seen to-destruction testing where a U-lock is holding a cable or chain and the cut-up shackle has just enough play in it to allow the cable/chain to be released.

If you use the Litelok X3 to attach to a solid object, and then attach a chain to the X3… or another U-lock, then the thief can simply shift their attack to that other locking device, cut thru it quickly and perhaps even ignore the X3.

The X3 is best employed to disable the locked object (bicycle or motorcycle). Lock it around the bike in such a way the motorcycle or bike cannot be quietly rolled away. Let that be the X3’s job. Locking it around substantial parts, like I do with my frame and rear wheel, means it has to be cut clean through in two places to be defeated.

If you also want to lock the bike to a solid object (and you should) let the second layer of your locking scheme do that. In my case that second layer is another big U lock and a big-ish chain.

Compared To Other Motorcycle U-Locks

Xena XSU310

I bought it for use in a marine environment where its all-stainless construction is resistant to corrosion/rust. This lock is a monster, with an 18mm vinyl-coated chromed steel shackle and a monobloc stainless steel lock body. Its internal shackle width is about 105mm (4 5/32 of an inch), and its length is 11.5″ (292mm). Thats enormous, but its shackle width is a hair less than the X3.

The Xena’s sheer size makes it great for reaching out and grabbing onto things. Its 1.7kg (3.75 lb) weight seemed really heavy until I picked up the 4.6 lb X3. The Xena also incorporates a locking mech that is anti-twist, which means you need two cuts to defeat it if its wrapped around something big like a wheel. This is perhaps the most secure motorcycle U-lock around – or rather… it was.

Pragmasis/Lockitt DIB Series

I’ve got a couple of these. They use interchangeable U shackles in differing lengths. All are 87mm wide internally. The one pictured is the 260mm length, and I have another that is 190mm long. 87mm is narrow compared to the X3’s 105mm, but still perfectly usable.

The X3 shackle is nicely wider than the DIB

In the montage of images up at the beginning of this article, you can see the DIB used as my second-layer lock around the back wheel and frame. The narrower DIB is a bit fiddly fitting it in there, whereas the X3 is noticeably easier thanks to the increased width. The DIB locks are rated Sold Secure Motorcycle Gold.

The 16mm shackle of the DIB locks is respectable even for a motorcycle lock, but compared to the 18mm Xena and now the X3 in 24+mm …

Top to bottom: X3, Xena and DIB

Worth Calling Out

You can see in the pics above that the X3’s internal steel shackle has squared-off ends. These prevent it from rotating should someone find a way to cut through it. That anti-twist feature makes it more likely that not one but two cuts will be needed to truly defeat the lock and free up whatever it was you locked it up to.

In my case, since I am locking the frame and rear wheel with the X3, whoever is coming after my bike will need to complete two complete cuts of the shackle to get it off to free the bike.

Thats It?!?

I hope so. The plan is to just use this lock and nothing ever happens. Until thieves work in gangs with tilting flatbed trucks, or start using light sabers to cut locks off, my plan is the US$300 I spent on this lock is an investment that keeps me out of the headlines.

Ebike Battery Charge Safety: Heavy Duty Cutoff Timer

Add a safety layer to ebike charging practices, with residential/commercial grade components rather than the cheap stuff.

Nip It!

In my previous post I dug into the subject of using a mechanical cutoff timer plugged between your ebike charger and the wall. It gives you an added layer of safety when charging your ebike battery. Using a timer, coupled with some advance planning and brain power, you physically cut the power to the charger. In doing so you prevent even the possibility of a charger or battery malfunction. I went into the details thoroughly in that post.

To do this job I used a cheap, basic timer bought online that I have been using for years. Recently, others who also use this timer have taken it apart and looked inside. The verdict: It will do the job, but it is not particularly robust or fault-tolerant.

How Do We Beef It Up?

Use a better timer. Chances are pretty good if you live in the USA you have already seen and used this exact timer many times. They’re on the wall in almost every hotel or motel bathroom: The timer that turns your heat lamps off after a short while so the bulbs don’t burn out. You also see them on whole-house fans in private homes (you have to live where it gets hot to have these).

The one brand that seems to be everywhere and in use for decades is Intermatic. They seem to last forever, so the hope here is it will also last forever with your ebike charger. Since it is made to conform to residential electrical codes, its internals should be safer and more robust than any teeny tiny timer you bought on the internet.

Following that, what will we use to go along with it? After all they’re called ‘wall timers’ because they are usually built into walls and connected to your power grid. We want this thing to be reasonably portable, and still safe.

Lets Make A Parts List

I have built a few of these. I have bought parts from a local Home Depot, or from Amazon. Neither is the best place for everything. Some parts are cheaper at one source than they are at the other, but the bargains are all different parts. Buying everything from just one or the other, you end up spending the same amount of money. If you want to save a few bucks, shop around locally and buy a few bits in town. You should be able to save about US$15. I am going to stick to using Amazon on this parts list.

Project cost if bought from Amazon is about US$75 if you buy the 10-foot cable. Thats a lot more than the cheapie timer but it is WAY less than your fire insurance deductible on your garage.

Intermatic 12-Hour Spring Wound Timer

Different versions of this timer exist to span ranges from a few minutes to a few hours. This 12-hour version (Model SW12HWK, Single Pole Single Throw) is less common. It is usually an order-in item if bought locally. I chose 12 hours because I like to charge big batteries (35ah!) at low current rates, so a long timer works better for me. Its also almost guaranteed to work for a variety of other jobs, so I am not blowing US$75 on something that is only good for one thing.

The image above is what you will see on order pages. It is a bit deceptive as the timer does NOT come with the decor-style faceplate seen in the product image. You have to buy that separately.

Alternatives:

The commercial series by Intermatic has a slightly different look and a faux brushed-aluminum 1-piece faceplate (In days of yore it was made of metal. In modern times its plastic). These are available in a 4-hour version (model FF4H) and a 6-hour version (model FF6H).

Both models, like the 12-hr version, are SPST

This shorter duration may be a better choice, timewise, for more mainstream, manufactured-ebike batteries that tend to be in the smaller 12ah to 20ah range. That is the good news. The bad news is these versions cost more money and can be difficult to find, even on Amazon where you will see some sellers wanting ridiculous prices for them (the links above are the best prices I could find).

This increased cost is slightly offset by there being no need to buy the next item on the list, the decor-style wall plate cover.

White Decor-Style Wall Plate Cover

This is what you’d think the timer would have come with above but doesn’t. I chose white to match the inner timer plate (which DOES come with the timer). The inner plate fits directly into and onto the ‘decor’ style wall plate.

There is no requirement to buy the linked Leviton brand as all decor-style covers are a standard size.

1-Gang Weatherproof Deep Wall Box

This is what we are going to mount the timer into. Heavy duty aluminum boxes like this are ordinarily used to surface mount a switch onto a wall, like bolting one onto a metal wall or similar. The box will come with little screw-in plugs so the big extra hole in the back will be easy to seal up.

I chose to use the ‘deep’ version of a wall box so I have more room to work in. I also used the larger 3/4″ hole version as again bigger holes are easier to work with.

Two Strain-Relief Connector Fittings

One of these comes out the top of the wall box, and one comes out the bottom. They have rubber gaskets inside and when you screw them down, the gasket tightens onto the cord running thru so it is held fast and can’t be pulled apart without deliberate malice aforethought.

The pictured part above has a metal ring that could be used inside some wall boxes, but in this case we’ll discard it and just screw it tight to the box. I have bought this exact pictured part and used it, but in the pictures below you will see I used a slightly different version I bought locally.

Lighted 12-Gauge Outdoor Extension Cord

Read the specs on this cord via the Amazon link above and you can see it is quite a beefy cord. The SJTW rating means its meant for hard-service, rated for 300v and approved for outdoor use. The one I linked is good for 15a and 1875 watts. As importantly, since I am going to be splicing this cable into a residential/commercial electric timer switch, and those switches typically use 12 gauge wiring, I wanted a cord that also used that same thickness of wire, even though it is by necessity stranded and not solid copper wire.

The seller I linked sells the cord in a variety of lengths. You can decide whether you want a short or long one. I went for 10 feet when I put mine together as that is what fit best from my outlet to my charging station.

Lastly, notice the cord has a lighted end. This will be handy for when the timer turns on the power. We know its hot by seeing the light at the end of the plug.

If you live outside the USA, your electrical cords will be different, so you’ll want to find a similarly overbuilt cord for your project.

Aside from two heat shrink butt-end connectors we will need, thats it for the parts. There is a complete tutorial on how to make reliable crimp connections here. You can refer to it if needed.

Lets Get To Work

Step 1 is to figure out just where on your power cable you want to place your timer box. For my project, since I was mounting the box in my garage I had to measure from the wall plug, to the place I was mounting the timer. I also had to be sure I had enough cord to reach from the timer to my ebike’s charging cable.

So… Using a sharp and sturdy cutter (12/3 cord is not going to cut cleanly with ordinary scissors) cut your power cord completely in half at your desired spot.

Next, cut back the cord insulation without slitting the insulation on the inner three wires. I used a utility knife blade held in my hand, and cut very carefully. Just as important to not slitting the insulation on the inner wires is to not slit yourself, either. This process requires considerable caution. There are specialized cord stripper tools out there to take the danger out of the process.

After this, strip a short length of each inner wire on each side of the cord. The end result should look like this:

With your two stripped ends ready, thread the strain-relief connectors over each end of each cord. Now run the two cords thru each side of the box, one from the top and one from the bottom. Screw down the connectors into the box, but do not tighten down the outer rings, so it is still possible to move the electrical cord back and forth thru them. When you are done it should look like this:

Now its time to re-connect the cord and put the switch in between. Here’s where things get tricky if you intend to mount the box vertically on a wall, as I did. This is where the deep box giving extra room comes in handy.

You only need to plug the hot wire (black) into the switch. The neutral (white) and ground (green) wires can be connected right back together again (note to folks outside the USA, your wire colors will be different and will match an international standard that – of course – we don’t use here in the States).

The neutral and ground wires are reconnected with simple heat-shrink, adhesive marine butt-end connectors. The hot wire is attached to the switch via its simple teeter connectors, which work fine on stranded wire even though they are meant for solid copper. This connection is a big part of the reason I chose thick 12-gauge electrical cord.

When deciding what side goes where, the Line side (male plug end) goes to the power source (the wall). The Load side (female plug end) goes to your charger.

Because of this Line and Load business, and the fact that I was mounting this switch vertically (notice the directional Top markings on the front of the switch) I had to run the top cable to the bottom of the switch (Line) and the bottom cable vice versa to the top (Load). Thats why everything is running around in a circle inside the box.

If you look to the right side of the switch you’ll see Line (2) and Load (2) plugs are there and reversed, which would solve this alignment issue. However, this second set of connectors are dummies lacking the hardware to be usable. They’re just blanks not used by this Single Pole, Single Throw switch.

Once you get to this step, all the real work is done. Carefully move the switch into the box, ensuring the connected wires are not subject to any pulling stress. You’ll want to be tugging back the still-loose electrical cord a little to help make room, but again don’t overdo this. You don’t want to cause any strain on the switch connections, and you have a deep-version of the box so there’s room to fit the cable behind the switch.

Screw it down carefully once its fit into place. The screws to do this came with the switch.

And now screw down the decor cover. Take care not to torque it down too hard as it is a delicate part and you can crack it if you go too far. Next, tighten down the two strain-relief connectors, which fixes the cord in place so you can’t tug it apart.

Those last two steps took only about a minute, and we’re not going to need much more than that to finish the job: The switch comes with a little cheapie hold-down ‘nut’ that is little more than thin bent metal. It needs to be that thin as there are almost no threads available for it to grab. Drop the inner timer plate onto the opening. Tighten down the nut so the inner plate is now fixed to the timer face.

Don’t overdo the tightening. You will figure this out as you see the plate bend inward as you tighten. I used needlenose pliers as fingertips don’t quite have enough grip to do the job.

Next, press on the timer knob. You’re done. You just created your heavy duty timer, that you can use to plug in between your ebike battery, or anything else you want to provide time-limited electrical power.

Now What?

Plug that sucker in and make use of it! This is the part where it becomes handy to have the lighted plug end. Turn the timer on and you’ll see the power come on via the little light. Come back a few hours later and the presence of a light at that plug will instantly confirm the power is on before you even glance at the timer dial.

Ebike Battery Charge Safety: Use A Cutoff Timer

Lets easily add a layer of extra protection to help safeguard your home and loved ones from a battery fire.

We’ve all seen the news reports. When compared to the number of ebikes out in the world, battery fires are extremely (EXTREMELY) rare. But when they do occur they can be catastrophic to life and property.

As a daily commuter who also uses an ebike for an auto replacement, I have been charging daily for years. In fact, since I charge at home and at work, I am generally charging twice daily. So I do a lot of charging, which increases the possibility of a failure, even if it is a small one.

Lets skip to the good part first:
Here is the light-duty timer I use. It costs a whole US$9.99 on Amazon. I have several scattered around at my home, my office and in a couple of garages.

With that out of the way, I’ll spend the rest of my time telling you how to go about using it.

What Kind Of Failure?

I have had chargers fail to stop at the target voltage on three separate occasions: They kept on charging. In one case I was using a premium charger with an 80%-charge setting, that was supposed to stop at 55.4v on my 14S/52v pack. A 52v pack is really fully charged at 58.8v. I walked into my garage and saw the charger with its fan merrily humming along; its little red light telling me it was feeding current into my battery… and it was now at 59.5v. Luckily for me it wasn’t enough to cause the battery to combust, which it could have if I hadn’t walked in and reacted appropriately

The second time it happened was almost exactly the same story. Diagnosis worked through with the charger manufacturer determined an internal component failure. They were prompt with warranty replacements, but who is going to warranty my garage?

What About The BMS?

All drama aside, the BMS likely stopped the battery from accepting the current from the charger at 59.5v. This second layer of safety prevented disaster.

Whats a BMS? There is a layer of protection inside the battery. Ebike batteries typically have a Battery Management System inside that is supposed to stop accepting current if an overcharge is in progress. But if you read the headlines, you already know those can fail too.

As part of my solution to this problem, I started using chargers made for outdoor commercial and municipal use. These units have Mean Time Between Failure ratings in the hundreds of thousands of hours. They are built to work trouble-free for decades.

That is a whole different story explored here: An Ultra-Reliable Ebike Battery Charger.

Add Another Layer To The Onion

We’re going to address the failure-to-stop risk specifically: Plug a countdown timer into the wall, plug the battery charger into it, and set the timer to physically cut the AC power clean off before the battery even has the chance to reach a 100% state of charge, let alone an overcharge. If everything works correctly, this adds significant safety to routine charging.

Whats a Countdown Timer?

Think of a kitchen timer. You want something to cook for 10 minutes, so you set your timer to ’10’ and when 10 minutes expires, you hear the timer going off with a bell. If you have an oven with a cooking timer, it will also shut the oven off.

So What?

Thats what we’ve got here: An oven timer that plugs into the wall, and instead of going ‘Ding’, cuts the power from the wall socket to the charger when time runs out.

What that will do is stop a charger from even enjoying the possibility of failing and overcharging your battery. So we will be gaining two things: First, we’ll be making it more difficult for the charge process to induce a battery to combust. Second, we will be creating a way to charge the battery to a less-than-100% level, which will lengthen its lifespan.

Extending Battery Life

This second benefit is optional, but makes sense to take advantage of if you can. If this is a new topic for you, here is a good explanation of the plusses and minuses of the practice. I have cue’d it up a couple minutes in to skip the technical portion of the explanation.

How Do We Set The Timer?

You may have to go on a short fact-finding mission. You need to know how much voltage your charger puts into your battery in a given time period. You need to either have a charger that displays the current voltage level, or an ebike display on your handlebars that shows current battery voltage (i.e. the display shows something like “46.2” volts instead of showing five bars in a pictograph, which is functionally almost useless, but not uncommon). If you don’t have a voltage display, you will want to fudge one.

Two DIY ways to do this

Use a Multimeter/Voltmeter and take a reading off of your battery leads
Use A Watt/Voltage Meter and plug it inline to your charge plug or cord

I describe the Watt/Voltage Meter in a fair bit of detail in the ultra-reliable ebike battery charger article, so I will, for now, just link you to it and let you take it from there. You can use that information, along with the separate instructions on how to make dependable crimp connections, to put together an inline meter fairly simply. Additionally, you may be able to come across a meter that just plugs straight into your battery.

When we get into the description of doing a robust DIY timer, one of the optional ways to do it will let you directly attach an inline meter.

We’ll discuss an inline meter as seen above, when we describe a custom timer build in a separate article.

You could also use a multimeter, or voltmeter. Those are pretty simple devices you can get for cheap online, or in your local hardware store. You don’t have to spend a lot of money to get one much more accurate than the typically marginal accuracy of ebike displays and watt meters.

Here is a cheap multimeter (US$9.99 at time of publication) that will do the job. I am linking it here chiefly because it has an instruction manual written in understandable English.

For about US$35, you can get hold of a much higher quality product. This unit has a neat feature where the leads you need to plug into for a given job are lit up with little LED guide lights so you can’t screw that part up.

Since I do a fair bit of hobby work around electrical things, I use this slightly fancier model, that runs about US$60. Its a little more accurate, and has a couple of added bells and whistles. Using it I found my voltage display on my Bullitt hill climber was consistently 0.5v lower than the actual battery voltage.

Find Volts-Added-Per-Hour

Now that we have a method of determining battery voltage, lets figure out how much our charger adds in an hour.

I plugged my multimeter’s leads into my battery charge plug. I get a reading of 55.8v. Thats my starting point. I plug in the charger and set an alarm to come back in one hour. My alarm goes off and I hustle back to the bike to take another voltage reading.

57.2-55.8 = 1.4. My charger puts in an additional 1.4 volts into the battery per hour. It is not such a bad idea to run the battery back down and test it again. Go for a third time on general principles. See if you come up with the same number or maybe you want to average three slightly different numbers.

A Worthwhile Detail To Note:
Ebike battery chargers use a method commonly referred to as “smart charging”. Technically speaking, this is what is known as “CC+CV Modes”, where the Constant Current mode pumps power into the battery at the charger’s full current level (usually something like 2 amps). But when the charge starts approaching the voltage limit the charger is set to reach, it switches to Constant Voltage, which slowly ramps down the current being fed into a battery until it gently stops at the final target voltage.

So, bearing in mind the above, we don’t want to be measuring the rate of volts-added-per-hour when we are up near the top of the battery’s capacity, because we will be measuring when the charger is in a ‘slowing-down’ mode.

Now What?

Well, in the above example, if my battery is at 55.8v, and I want to charge it to 100%, I now have an idea how long it should take to fill it up. My 52v battery is fully charged at 58.8v. So 58.8-55.8 = 3. I need three volts. My charger charges at 1.4v per hour … and I know CV mode will slow the charge rate down near the top.

I could be conservative and just set it for two hours, knowing 2.8v is close enough to 3v, and its safer to come up to a bit less than 100%. Or if I need that 100%, I can set it to 3 hours. That is too much time, but not by much thanks to the CV mode slowdown at the end.

In practice, this is a lot more thought than you will need to put into the process on a routine basis. What you’ll be doing is ballparking what you set the timer to, and even if you go over or under by a bit, if you do your part on the math it will not be enough variance to matter if Something Bad happens.

And if you use the timing method to cut power off at a lesser charge state of, say, 80%… you can routinely be off a bit and instead of risking a problem, you’ll end up with maybe an 83% charge. Or 78%. Not enough to matter on most rides.

Myself personally this is exactly how I ballpark my charges with my timer: I don’t worry about getting anything exact and I shoot for 80%-ish.

We Are Ready To Use A Timer

So we’ve done all of our homework. Its time to plug in a timer. What timer should we use? I personally prefer mechanical timers. The old-school spring-wound kind that are immune to weirdness like power interruptions. The kind that are not programmable and are thus not subject to programming mistakes. The kind that need a positive action to set, and are not so susceptible to a little oops like pushing the 4 hour button instead of the 2-hour button. Also a mechanical timer is more granular in how you set it. If you want an extra 10 minutes on today’s charge you just turn the dial another click or two.

Here’s the timer I have been using. Amazon tells me I have bought five of them over several years.

Picture taken at my professional photo studio (i.e. on my garage floor)

Its a whopping US$9.99 at the time I am writing this. I have been using them for years and they work easily and effectively. Is this a robust solution? No it isn’t. Its just a super cheap little timer. Folks on the internet have taken theirs apart and reported the mechanism inside is not very sturdy. In recent weeks I have found my main one at my home is feeling a little worn out when I turn the dial.

BUT its one hell of a lot better than nothing. And if its this or nothing, spend the ten bucks, get this and hopefully you will be a little safer for having it.

If instead you want to try and do this job with something a little better made, then read where I

Build a Heavy Duty Countdown Timer

BBSHD Programming For The Pedaling Cyclist (2023 Update)

After a few years of incremental refinements, lets re-visit BBSHD programming for pedal assist settings that give you a workout, and are also gentle to the drivetrain.

After A Lot Of Tinkering…

I have written in years past about efforts to develop BBSHD settings idealized for cyclists who want to pedal, and even get a workout. I’ve followed up with revisions here and there as I continued to poke at things.

Things have progressed to the point it is worthwhile to revisit this subject, supplement the original article and share what I think is some progress.

What is here was originally part of my Bullitt hill climber build series, mixed in with stuff about that bike. After a while it became clear I needed a dedicated post, where these settings aren’t buried inside something else so nobody knows they exist.

So. Here we are.

Tools

The screenshots below are taken from the widely-used, open source Bafang Configuration Tool originated by Stefan Penov. His software (still perfectly usable) can be downloaded here. My screenshots use Version 2.2b, which was taken up by Laurent V. His later version can be found here. I only use it for screen shots.

To do the actual work, I have long owned a Black Box from Lunacycle which has served me very well. In more recent times I have purchased a cheap ‘programming’ cable, a USB-C adapter and use the Speeed app on my Android phone. This lets me stash the cable on the bike somewhere so I can adjust the BBSHD whenever needed.

Goals

There are no perfect BBSHD settings for everyone. I am just showing you mine. Hopefully you will see something useful for your own journey. These are my goals:

GOAL 1: (COMPLETELY) Eliminate Excess Drivetrain Wear

On the internet you hear stories about how a powerful mid drive tears up your drivetrain. It doesn’t have to be this way. When I see reports like this I know someone did something wrong.

In separate articles I make the case that on the one hand, a builder needs to use the right components for the bike to work right:

How to Build A Mid Drive Ebike That Doesn’t Break

On the other hand, making it work right long-term is also a function of the cyclist following a few simple rules.

How To Ride A Mid Drive Ebike Without Breaking It

But on the gripping hand, the third essential ingredient for a 100% reliable BBSHD-powered ebike is to adjust motor settings so it doesn’t behave anything like it did when it came from the factory.

Many of the settings described below are exclusive to Goal 1.

GOAL 2: Set Pedal Assist So The Bike Won’t Run Away From You

A cyclist wants to get a workout while riding. This is difficult with a stock BBSHD, because factory-set pedal assist is so powerful. We want PAS to not overpower us … but preserve the option to do that if we want to take a break.

This is crucial to eliminate the complaint against cadence-based pedal assist from people who think they must have torque-based assist to get a natural cycling experience.

Taken together as a whole, settings as described here mean you can set the BBSHD (or BBS02!) motor to a low pedal assist value that provides only a small bump in power when you pedal. This means when you want to accelerate or cope with a hill, you have to put some muscle into it just like on an analog bicycle. Want to put in less muscle? Fine click up what is now a gentler increment of power.

The settings taken together kiss goodbye stuff like unnaturally strong initial power application, shutdown lag and other bits that detract from a more natural cycling experience.

Goal 3: Easily Shift The Power Curve Up or Down Without Screwing Everything Else Up

This entire settings package – taken together – makes for a refined system. We’ll see how you can easily increase or decrease PAS power output levels across its entire scale, so all of that fine tuning stays in place.

Got all that? Here we go, then.

Fraternal Twins

In line with Goal 3, we will look at two configurations that provide very different levels of pedal-assist power.

One is a low-power setup – developed for use mostly on flat land – for high-cadence, high speed cruising. This setup gives a max sustained output of 400-450 watts on Pedal Assist Setting #9. That is not a lot considering I am using a 30a BBSHD on a 52v battery. With that much power behind it, a BBSHD can easily hold 1750 watts. This is a significant reduction with big implications to range and running the motor well below its redline.

We’re limiting PAS power, not throttle power. If you want to put down 1500w to the ground, use your thumb. Current Limit on the Basic Screen is usually the tool for limiting power output, but that cuts everything across the board. We won’t do that.

I said this config was developed for flat land, but it works on hills if you have the right gears. My Apostate uses this setup and it is a light, short-wheelbase mountain bike with a 40T front ring and an 11-46T cluster.

Small and nimble with a pie plate rear cluster, The 26″ Apostate (a rescued 1999 Intense Tracer) doesn’t need big PAS power.

The other configuration is a high-output setup made for high-cadence, slow-speed riding up the steepest of hills. Its maximum sustained PAS output is in the 950-1000 watt range. This config also works great when you are on flat land: just stay down at PAS 1 or PAS 2. Save the big settings for a rainy day (not literally :D). I use this on my hill-climber Bullitt.

You don’t have to use the high output config on an alpine cargo bike, but it certainly works well with one.

Here’s The Rub

These two configurations are arrived at by changing only one setting. Otherwise they are the same. We’ll talk about the one change at the end.

The Throttle Screen

Start And End Voltage

I am using a commonly-known enhanced range of 11 and 42 (standard factory setting is 11 and 35). This wider range makes it easy to smoothly modulate power in small increments (as low as 50 watts based on what my displays tell me). It eliminates the jerky on/off switch that is usually a BBSHD throttle.

Designated Assist Level

By setting this to 9, we tell the controller to treat throttle peak output as if we are on PAS9. Skipping ahead a little, that setting is unlimited at 100% for speed and current limits, so the throttle has access to full motor power. If you are setting a bike up for your 4-year-old, or Grandma, maybe don’t do that.

(Throttle) Start Current

Start Current for the throttle is reduced to 2%, which is really low. The throttle starts laying on power very gently. You hear a lot about how Bafang motors bang and jerk on the chain. 2% on throttle Start Current ends that. If you find 2% is too gentle, try 5%.

The Basic Screen

What I did with the Speed Limit percentages was simply start at 100% on Level 9, and work my way back in 5% increments down to Level 1. Doesn’t look very scientific, does it?

Some people are looking for Speed and Current Limit settings to give them exactly X output at Y setting based on Z input. My take on this: attempts at precision are wasted effort. These settings are ranges with somewhat fluid boundaries, and will not yield hard limits.

For example: the Speed Limit percentage value is not the percentage of your ground speed. Its of motor speed. As in the percentage of max motor rpms. And those max motor rpms are affected by battery voltage, which is on a curve as the battery runs down.

Thus you see basic increments in my various Limit settings: Over time I have decided these increments give me enough change in performance from one to the next to make them worthwhile, while at the same time not emasculating the low PAS settings with limits too small to be useful.

Lots of room here for changes based on personal preference.

The Assist 0 limits of 1 and 1 are there to preserve the normal function of throttle when you set the screen to Level 0, which disables Pedal Assist. This lets you pedal with no motor support without turning the motor off. Throttle remains available in case of an unexpected need.

The Pedal Assist Screen

This is where the magic happens (click an image to enlarge).

ABOVE LEFT: the high power config. RIGHT: The low-power config. Only Current Decay and Keep Current are changed, and changing Keep Current is not necessary.

NOTE: The screen shots above have a graph that does a decent job of trying to explain how the settings interact and affect performance. Want to know what all these settings do? Look at the graph.

Start Current

Set very low at 2% for the same reason it is at 2% on the throttle screen: kinder/gentler initial engagement (5% is a good Plan B).

Slow Start Mode

Set as gentle as is known safe for the BBSHD controller. Lower numbers here = slower starting and 3 gives me the gentlest motor-safe slope to that curve.

Start Degree Signal

Set to a fairly prompt 4. The problem to solve: starting from a stop at an intersection, while on a steep hill. Specifying a lower number of signals before the motor kicks in makes it start up sooner. Start Current and Slow-Start Mode also figure into this equation so this relatively fast engagement doesn’t cause any drivetrain strain.

Stop Delay

Remains as small as is safely possible to preserve the motor controller. Setting it low like this means when you stop pedaling, the motor stops promptly.

HILL MODE: Current Decay Set To 8

This is the one setting that causes the big changes.

In conjunction with the other settings/screens as shown, changing ONLY Current Decay changes the maximum sustained output of the motor while on pedal assist. A setting of 8 gives maximum output to the drivetrain. Current Decay acts, effectively, as a volume control that goes from 1 to 8.

If it is set to the maximum of 8, Current Decay is minimized almost to the point of eliminating it entirely. This makes sense when riding in steep hills.

Setting Current Decay to a low number to increase its effect makes sense on flat ground. You need less power to maintain cruising speed. But in a granny gear, pedaling like mad and crawling up a steep hill? The last thing you need is for the motor to cut back power. So for hills we set it to 8.

As such, when grinding up a hill at 60+ rpm cadence, and 4-9 mph (7-15 km/h) the motor stays consistently strong.

But…

I said earlier setting Current Decay to 8 almost eliminates its effect. Here’s what that means: As you slowly honk your way up a slope, you get strong, consistent power assist. As you crest the hill and transition to flatter ground, or the hill decreases in slope for a segment, typically you stay in the same gear and spin the crankarms faster (before you think to upshift to a smaller rear cog). That is when Current Decay eases back in again. As you start spinning and speed increases the motor will back off the power.

I am describing Crawling up hills like this one (click for interactive street level Google Maps view)

This will also happen if you just upshift on flat ground and start pedaling furiously. Part of this effect may be due to the low gear you are in and the upper rpm limit of the motor. Since Bafang documents nothing and we are left to guess at everything, its hard to say. But I like it this way as it gives a more natural pedal assist behavior.

NOTE:
What I do on that climb up Hoffman Avenue pictured above: You can see if you follow the Google Maps link, it has many different slope angles from bottom to top. I set my gear to a single generous ratio – one cog lower than I’d need on an analog bike. Then I vary my PAS setting up and down as the hill changes slope, never shifting gears. Varying the PAS assist up or down lets me ride like a cyclist, working hard on the pedals as I choose, and maintain my cadence regardless of slope. Thus I am using my PAS panel to take the place of a gear shifter.

Its a technique not possible with an analog bike if you don’t want to pop a blood vessel, and one of the reasons ebikes should be recognized as a different system to master with different rules than old-school bicycles.

FLAT MODE: Current Decay Set To 2

We have taken the same configuration and done nothing more than just turn the volume down.

With the “volume turned down”, pedal assist is still pretty strong at slower speeds with low cadence… exactly what you’d expect coming off a dead stop. But its not so fast you are giggling and leaving people in the dust. You’re starting off only a bit faster than a normal bicycle.

Want more power off the line? Let the throttle help. Don’t do it from a dead stop because thats what kills drivetrains. Give yourself a pedal revolution or two before hitting the juice for, say, 2 seconds.

You’ll know for sure Current Decay is limiting power when you look down on PAS 9 at full speed and see only 400w and maybe 6 or 7 amps on your display.

Stop Decay

This setting is at zero. Once the motor’s assist shutdown is initiated, this setting dictates the slope of the shutdown curve.

I ran some experiments recently as part of an internet discussion. A suggested setting of a whopping 1100 ms (i.e. set it to 110) produced nothing negative. The cutoff happened so fast I couldn’t argue it hurt anything, and I tried to create a problem. It was still a shutdown that happened so fast I couldn’t find a way to screw up.

Keep Current

This is the second of two changed settings, but it is just personal preference, and not necessary to make the big change that Current Decay provides.

I like a strong current reduction when Current Decay kicks in. I have found at high cadence I like the motor to let me work harder than it does with 40% assist. So I kick Keep Current down, get a little more exercise and claw back some efficiency in the process.

(Not) The End

As noted above, there is no ideal suite of settings for any BBSHD. There are also different ways to try and get the same end result (witness how many leave all Speed Limit % settings at 100). I think doing it this way is simpler, and preserves desirable nuances in motor behavior, rather than just zero’ing them out.