Recent content by mikemarmar

Yeah...the cells don't seem to be getting hot so that's good. I will check the terminals I can't access sometime in the next few days. The bluesea switch on the other hand seems to have a bad internal contact, but that's a separate issue at this point.

I ran the same experiment again (high current (150A) discharge, followed by lower current charge (60A)) and the imbalance is now pretty much gone. So whatever is going on, the imbalance gets larger when I do low current discharge + high current charge (normal usage) and the imbalance gets...

So this is interesting. I just tested charging from 50% to 100% at 70A charge rate. The same problem presented (cell 1 voltage goes high around 80%, then drops back down when the other cell voltages start to rise). However, it was much less dramatic this time. Cell 1 never really went above...

Yes good point I will grab that fluke meter and poke around

Yeah cell 1 is the same that went high while charging. Running that test again right now to make sure it is reproducible. Next step is to take everything apart, and run some of the tests you all have recommended. I'll let you know how it goes, thanks again for the help and suggestions!

So after drawing down 500Ah, cell 1 is at 2.8v while cells 2-4 are around 3.15v. Cell 1 dropped below 3v fairly early on (around 40% SOC) and has stayed low. I guess the next step is to take the pack apart and try to figure out if it is a bad connection or if one cell is bad.

Hm yeah I might have to go ahead and disassemble and make sure my connections are good. I made my own bus bars from copper flat stock so it's possible that there is a burr I missed. Also, the terminals on these cells are very prone to stripping so I might not have tightened one of the bolts...

I would say mostly sitting. It has been powering some small loads the whole time, but the victron has mostly been plugged in and floating the pack at 13.2v, which tends to settle around 70% SOC and stay there. The batteries were in full use for a 2 week trip, and otherwise the van has been in my...

Thank you for the quick replies. I will have to do some further testing it seems. To answer some of your questions: Good idea, I will do this first. The battery has been on one long roadtrip and something may have come loose. The cells were top balanced at 3.6v before the pack was assembled...

Hey all. A couple months ago I put together a 560Ah 12v pack (2p4s) using the 280Ah Eve cells (It is possible that I actually have the 272ah Lishen cells....the vendor on alibaba was a bit unclear). Today I was charging up the pack from ~60% to 100% using my victron compact multiplus 12/2000...