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Revived an old 400Ah 16S bank that had a rodent-damaged, unreliable BMS. Swapped it out with a Seplos BMS in order to be able to get it communicating with the other batteries on the wall. It's alive and taking a charge. Still waiting on some beefier bus bars and need to enclose the BMS before...

This was back in 2021 - I managed to short out a LifePo4 pack (before my coffee kicked in). This happened in the process of dismantling a LifePo4 48V/400Ah battery in order to replace it with another battery. I didn't think about the fact that the pack was still live while unscrewing the nuts...

Just following up here - after much iteration and deliberation, I found a decent solution for this. I grabbed a chain hoist ($50), sling ($13) ( and D-rings ($6/ea) from Harbor Freight and engineered an eye-bolt I can put enough weight on (using a 4x4 and threaded 1/2" rod). Had to crawl around...

So I just spoke with David Bly at terravolt.net. He’s super technical and worked at Iron Edison. He’s very familiar with this issue. Based on his experience, the issue is caused by seepage from the battery cells, not external moisture. Apparently, the Flexnet DC component that’s part of my...

I’ll check out the factory outlet next time I’m back in Germany but I can’t justify the retail prices personally for very occasional use. Different if I were an electrician by profession.

Haha yeah would be nice it the company was still around to honor it.

Iron Edison was (they're out of business now) a company in Colorado. Originally, they built their own batteries out of CATL cells. Our house came with one of these batteries when we bought it: Unfortunately, the BMS on this battery had become unreliable, likely due to rodents that lived...

Just closing the loop on the balancing - the NEEY 4A balancer has done a great job balancing these out:

Two batteries did not burn. I hooked up a bench power supply just now for testing and was able to power up both inverters, so likely those are okay and all 4 batteries are toast.

They were probably not. There are specific gloves for electrical work. But… they were what I had and they 100% helped protect my hands. The little blister was gone after two days.

Yes, that's what I did afterwards :)

This is a detached garage, no plans for insulation. :) It was a lot nicer working in the attic without it. :)

The Seplos BMS does passive balancing, which has a number of drawbacks compared to active balancing from my understanding - especially given that these cells are a few years old and seem to have drifted, I am hoping it'll make a difference. It also just sounds fun/interesting :)

I may just get a copper bar and put it across all three points to be sure. This is going to be used for a pretty beefy battery pack (16s 400Ah) so may as well minimize heat and resistance...

Indeed. They say it’s UL listed. The design is completely changed. Copper bars

Fair enough. At this point, for my setup it seems to be a (possibly lazy) way to improve things with little additional effort - and they’re not that expensive in the bigger scheme of things. Was able to grab the NEEY 4th gen open box for $110 shipped from the US.

Oops I missed this post. Thanks for the pointer, will investigate!

Yeah that sketched me out. That stuff’s poisonous too.

Yeah, I just tried it - essentially following these steps: 1. Turn off both radians, as well as the Flexmax charge controllers 2. Turn off BMS 3. Turn on a single Radian 4. Turn on BMS Goes straight back into SCP protection. :(

Some learnings/updates for those following along: Battery #1 is actually intact, but can't handle the inrush current of even a single Radian by itself. I managed to boot up the Radians using a bench power supply, and then added the battery. It is able to take a charge and discharge...

Anyone make progress on an enclosure yet? I found a plastic box on Amazon that is plenty big enough to contain the BMS, but I'm wracking my brain on how to mount the board - since both sides of it need things connected to them (battery terminals and balance leads on the one side and the RJ45/DIP...

Here's what Seplos said. So copper bar it is.

They were electricians I paid a non-trivial hourly rate :)

Pretty much. I live on the central coast of California, very mild Mediterranean climate.

Andy does a good job explaining it in this video:

I don’t believe anyone here knows. So far, GSL has not shared a root cause with me. Still asking though.

They’re unfortunately damaged and no longer workable safely. Chemicals oozed out of some of the cells and burnt/melted balance wires.

I just built a system with their Re-Volt batteries. Pretty good to deal with, definitely a very small company though.

Just to leave this here for people who may be looking in the future: This is a BMS made by Pylontech.

I have a question out to GSL to find out if they’ve identified/fixed a design flaw here. Their answer will determine whether I pursue a replacement from them. I really don’t want to sell the replacements, I think that would be extremely unethical at the least.