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by Aurornis 721 days ago
That’s the forum I followed.

The failures often came from BMS or other parts, too. There’s a lot of focus on the cells, but people are buying whole packs with a BMS.

2 comments

I buy that the bms aren't very good and are drastically hurting your system. Much lower key stakes, but I have an Andis Supra trimmer I rely on a lot, but it's charger has basically no low key mode: it will pump 10W+ power into these 2S cells forever. It's criminally bad battery management, will absolutely nuke the heck out of these high end cells, if you forget to pull it off the charger.

To me, the main thing is observability. Too many people trust their systems. We need to see how things are going. As the voltage converges to peak, we should be seeing the amps level out.

We can't just trust the machines, ever. We need to be observant. Ultimately I think we'd be able to review & get rid of bad equipment more effectively, but we should be in tune with what these systems are doing, should be aware that - oh hell - we are at peak voltage and still pushing power in, and we need to stop. These systems need to report what they are doing. Being blind consumers makes the economic system weaker; these systems should all report what they are doing.

Then that’s more the issue with the BMS rather than the cells
Problems with the BMS can become problems with the cells very quickly.
Yeah, but I would just buy the cells and spend more on a BMS. Or you can just use a low voltage cutoff and an active balancer for a smaller setup
In many of the systems, the BMS and battery are one in the same.

This article blurs the lines between the cells and battery system, too.

The post you were replying to was specifically about cells, and if you’re going for economy, building your own packs are substantially cheaper than buying packs domestically. Also less fraught when you’ve DIYed to diagnose and fix when things go wrong
This is why at https://gouach.com we've built the first easy-to-repair, easy-to-swap-cell battery! We're launching a Kickstarter soon, stay tuned (on our newsletter!)
Also prone to average people setting themselves or their houses on fire, eh?
Depends on how scrupulous Average Person is being. There's codes for electrical and solar installations that can be followed, and it's best to stick to the letter, even if you're certain it doesn't apply. And after that, you should get it certified by a licensed professional, but would also need a licensed professional to hook it up to the grid
I think you’re misunderstanding what I’m trying to say.

I’m talking about assembling your own multi-kwh lithium battery assemblies (pre-BMS even).

One wrong poke with a screwdriver, and all sorts of entertainment is likely to ensue eh?

And they’re big enough, no portable fire extinguisher is going to make a dent either.