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Comment by mwattsun | Hacker News Reader

I love my eBike but the biggest scam about them are the proprietary batteries. Imagine if there weren't AA, AA D, and C batteries but every electrical device you purchased had it's own battery shape and size at marked up prices that you had to purchase from that manufacturer. I would love to buy a second battery to extend my range but I refuse to pay $700 for a battery that only fits on my bike. The company that standardizes batteries will do well I think, because I can't be the alone one who wants this.

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Sadly, the manufacturers (Bosch, mostly) managed to convince various governments that the proprietary batteries with DRM are there to prevent tampering and this safety. So I'm not sure if it's going away.

Depends what eBike you are buying. There are currently many with the batteries you could get from Amazon / Ali.

You're not joking. The third link on Google for "bosch battery drm" is Hacker News talking about this. I'm surprised I missed this.

"These bikes are DRM'd to the hilt and any attempt at hacking them will cause the bike to brick itself which you can only reset at the dealership. You can do that three times and then it's permanent." user jacquesm 71 days ago

https://news.ycombinator.com/item?id=29201673

I mean Bosch left the battery business years ago. What the manufacturers care about is to limit risk under the constraint of government regulations. That said the E-Bike business is too small to come up with a bold move there but in electric driving there seems a lot of experimentation going.

Prior discussion on ridiculous ebike battery prices:

https://news.ycombinator.com/item?id=29562842

There's a similar phenomenon in cordless power tools. Each one comes with its own proprietary connection and hence tools and charging system.

There does seem to be a variation on the "give away the razors to sell the blades" business model here too. Batteries/chargers are much cheaper (like 30% of the cost) when bundled with tools than they are when bought individually. I suspect the bundles are to recruit new customers, after which they buy a few "bare tool" options because they're marginally cheaper, and then they find themselves needing to buy a battery at $90 instead of having paid an extra $30 for a bundle that includes the tool, a carrying case, a battery and a charger.

I know that there are some exceptions for dangerous goods shipping of lithium batteries if they're part of a device versus a standalone battery, but that can't be it, can it?

> I suspect the bundles are to recruit new customers, after which they buy a few "bare tool" options because they're marginally cheaper, and then they find themselves needing to buy a battery at $90 instead of having paid an extra $30 for a bundle that includes the tool, a carrying case, a battery and a charger.

What I wound up doing (and what I see most folks do) was more or less following a rule; your first few tools you usually buy bundles anyway. It's not till you get to your 4th or 5th tool that you ask whether to get the battery or not. (e.x. If you need a snowblower, you can probably use the lawnmower batteries. P.S. don't let your batteries get cold, the snowblower hates that.)

No, the expensive batteries are because of the long game. In the long game, you're still screwed. Eventually, those batteries -will- start to suck. Especially if your garage is not climate controlled and gets really hot, and frankly even after regular usage I'm surprised at how warm they are. The ability to output usable voltage for your tools becomes a Joke, you can charge them but the lawnmower stalls on a single wet leaf.

The battery cases are all custom but the batteries are the same 18650 you can buy on Amazon. My ebike has a custom case that fits in the lower frame. The actual case is held together with philips screws. And I could potentially increase range by swapping out higher capacity cells.

Are you sure about that? Because the battery management systems are proprietary. I'm just starting to research this, so don't take my word, but I'm pretty sure they take steps to lock you in.

What exactly does a battery management system do and how is it incorporated into the battery pack itself?

You should ask user battery management system hacker jacquesm about that because I'm just starting to learn

https://news.ycombinator.com/item?id=29201673

It can be smart and ensure longer battery life by not overcharging weaker parts of the pack. You never have perfectly even drain even if you use just 2-3 batteries. It can be just a gimmick to ensure you use proper TM cells instead of generic ones, in same vein phone chargers are split into manufacturer's and the rest, regardless of quality/power.

Vendor lock-in has been done successfully in the past and brands like Apple don't get hurt by it. So why should e-bikes be different.

Because those are shitty business practices that only serve the profits of the corporation. My hope is that people arrive to be better, rather than pull the same old bullshit to protect profits

> people arrive to be better, rather than pull the same old bullshit to protect profits

Of course not, batteries for electric cars, bikes etc. will be locked down as hard as possible and new ones will cost 2/3 of the new car price - sometimes replacement will not be available even from manufacturer which in effect will send perfectly good car to the junkyard - you can see this playbook in action right now with old Nissan Leaf.

From a user perspective, it protects you from the battery (by protecting the battery), increases the performance and longevity, and informs you about the state of charge. It connects to the battery at the cell terminals and to temperature sensors. A charger is a separate thing from a BMS.

So can it detect if I replace the cells myself?

If you replace with the cells with the same type, it probably won't notice the difference.

I have no idea about commercial e-bike BMS specifically. But in general, some BMS can, while others won't but maybe should because replacing cells can reduce the safety of the product. It depends on a combination of the cells, BMS, charger, and load. You shouldn't mix old and new cells in the same pack.

Of course, but as an educated consumer who likes to repair their own things I would get all matched high quality cells and replace all at once. If their battery packs don't detect or prevent this somehow then it wouldn't really matter to me.

There's an awful lot of DRM talk in this thread so that was my concern. The cells theoretically are the only parts that need to be replaced sans physical damage

I don't know about DRM. Be careful when joining batteries in parallel. You might not get full performance without the factory procedure for mating the battery and BMS together. Datasheets aren't enough to fully match cells, so the reliability and safety might be less.

The BMS ultimately just electrically contacts commodity li-ion cells in all cases that I've seen. You could use proprietary cells in some fashion but that would greatly increase the cost to the manufacturer as well.

Amazon does not allow selling 18650 batteries, but yes, they are a commodity item.

You can buy them off amazon.

Even if they are not allowed?

You can buy many things that are not allowed for sale in many places that do not allow them, but I would not recommend it in this case because it's a market where sellers like to post "9,999 mAh" batteries that are just pulled from discarded laptop batteries and maybe re-wrapped with a fancy label.

ilumn.com and 18650batterystore.com are legit as far as I know.

https://www.compliancegate.com/amazon-lithium-batteries-requ...

> Amazon prohibits the sales of the following products containing lithium batteries:

> Electronic cigarettes > Cylindrical lithium-ion cell battery types: 14500, 16340, 18650, 20700, 21700, and 26650

Batteries were the first thing I was looking for when buying eBike. Ended up buying eBike with 48v 21AH battery from a local store in Toronto that also has service department. Before buying made sure that I could buy replacement battery and yes - newer version with 25AH capacity is available from Ali and it is half the price comparatively to the local store.

Care to share who you ended up buying from? Also live in GTA

Emmo

My Bosch 500 pack died and I had to buy a new one for 900$. Pulled the old battery pack apart and measured good voltage on all the cells, I think the proprietary battery charge controller is busted.

If only the shops that fix iPhones could get into the ebike fixing business

Apparently there is a diode on the controller that fails.

https://www.youtube.com/watch?v=Ia4xe_R0qgw

I first hard to deal with this when a bought a DSLR camera. It is a Nikon and works only Nikon batteries.

The Samsung DigiMax V4 camera did it right in 2003. Comes with a high capacity custom rechargeable battery, but no need to find another one if it ever starts to wear out - you can use two rechargeable AA batteries instead in the same battery compartment.

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