Picked up a 200Ah lithium (EVE cells, 4S) build off eBay a couple of months back and fitted a JK BMS — the 200A active balancer version. Brilliant bit of kit when everything's working, but I've noticed my battery is sitting noticeably lower after a week parked up with absolutely nothing connected. We're talking dropping from around 53.8V down to maybe 52.1V over 7 days, which seems way more than it should.
Did some digging and it looks like the JK BMS itself draws somewhere between 25–35mA continuously, even in sleep/standby. Over a week that's getting on for 6Ah just from the BMS alone. My cells are pretty well matched so the active balancer shouldn't be kicking in much, but I'm wondering if that's adding to it too. Anyone know if there's a setting in the JK app to force a proper low-power sleep mode, or reduce how aggressively it stays awake?
I know the obvious fix is a small relay or a manual switch to cut the BMS off the battery entirely when I'm parked for more than a day or two, but that feels like a bodge. Curious whether anyone's found a cleaner solution or if this is just something you live with on the JK units. Using a Renogy 40A DC-DC charger and a 175W panel on the roof if that's relevant to anything.