you think the terminal touched the metal case? hmmm.. i thought that for a moment also, but, it wouldn't do anything if it was just one terminal right? it'd need to have contact in 2 points no? I assumed maybe a gecko or something ran across it, but didn't see any carcas. or you thinking the metal in the back that was scracthed away was the culprit?
ok, so i see your logic, scratched case from the poor welding in the back. the case is a negative charge. but.. arguably. there was no visible contact between the terminal case. plus, this system did work for a couple of weeks (never to 100% SOC arguably), and there was not changes or hits or fiddling with in that time. So what made it break now.
Charge status can expand battery cell causing pressure
Jbd all the way
Jbd all the way
1 - Assumption is mother of many fuck ups. Never assume any thing!
I think you can see the battery breakers, green ones, in one of the pics. Suntree i think, 125a (5x). Ok, didn't know Daly was so bad. but arguably.. maybe there was nothing for them to protect if the short was external? and yes LITHIUM mode implies that, but, it still has protections.
OK I see them. Will did a test of a portable outlet box recently and the 20A rated breakers didn't trip until over 60A iirc. He has since taken it down I believe.
yeah, I hear ya, as and engineer and a pilot, your words are correct. But we live in the Phillipines, 4th world country, and make due with a lot. We don't often have the luxury to go 100% on 100% of things. Arguably, this was close. and has been working for a while. torque was "hand tight" by an installer who has been doing it for 5 years and never a fire (so he says). and yeah, maybe this could be the cause. Just doesn't feel like it's the issue. I'm thinking a bad stem and the cut plastic base in the back. I'll add some foam too. Either way, there is no way of knowing nw
can you explain that? how would a not tightened terminal allow overcharging? Isn't the voltage what the voltage is? say worst case 58v. how would it be more? I could see maybe some micro arching, causing warmth. but dang... it was 100% for 20 minutes, and it was already on it's way down as the deye shows it detected 100% voltage, so it was throttling down the solar power, as can be seen on the solarman screenshots. yeah, the DIY is more painful. Our original intent, 2 years ago, was to have custom built racks that are easily cell-swappable in a large EV boat. That fell apart due to lack of technical expertise here, so we got railroaded here. Now, with the advent of cheap cells and cases, it seems obvious to buy a case, but, it wasn't 2 years ago. quite frustrating to try to be a leader in any field.
A micro arcing situation would have been going on the entire charge, building heat.
A loose connection creates higher resistance in that circuit. Higher resistance creates voltage drop reading.
Small differences in voltage between what the actual battery is seeing, and the inverter/bms could over charge it. Might have been okay when it was first built cycling over time good idea go back with a DVM and check from the terminal stud itself on each cell. Maybe that cell was getting over charged repeatedly. Good that didn't start a fire and burn down the place probably the fact that you had steel around it wasn't any wood around it to catch fire the heat was contained.
If they aren't communicating how is the deyw supposed to know it's at 100%
Bad assumption.
