[Aurornis]

I’ve followed the super cheap Chinese battery options for a while. It’s amazing how cheap they can be, but at the same time the number of early failure stories is alarmingly high. Getting a warranty exchange is hit or miss.

It feels a lot like gambling. You might get one that works for a thousand cycles without issues. You might get one that fails after a week. You might be able to get a warranty replacement, or you might spend hours every week trying to make progress on a warranty claim without any luck.

You’re right that there’s a lot of opportunity if you’re willing to buy used panels, Chinese batteries, and do all of your own work. However, the cost of equipment is falling while the costs of labor are rising, which is why professionally installed systems are still expensive.

[duffpkg]

There is a lot of information on this on the diysolarforum.com but if you purchase name brand cells, CATL/EVE from a good supplier these are the same ones used by all industry. They have a very good track record. I do not advocate buying from any random seller on aliexpress. There are not any mass market non-chinese batteries available for sale. Virtually all solar equipment of any fashion is chinese made.

[Aurornis]

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.

[jauntywundrkind]

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.

[h0l0cube]

Then that’s more the issue with the BMS rather than the cells

[samatman]

Problems with the BMS can become problems with the cells very quickly.

[h0l0cube]

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

[Aurornis]

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.

[h0l0cube]

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

[oulipo]

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!)

[lazide]

Also prone to average people setting themselves or their houses on fire, eh?

[oulipo]

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!)