Battery problems and LiFePO4

Author	Message
Revlac Guru Joined: 31/12/2016 Location: Australia Posts: 1297	Posted: 09:47am 20 Jan 2024       Cleaned up some of the trees that smashed the front fence there would be a truckload or more of other trees that I won't bother shifting, I haven't even looked down the back, Doesn't matter. The rain come in   horizontal and got everything wet under the verandah and 6 feet up the wall, in the end of the shed everything got wet,  but the solar gear was ok, the batteries BMS and The equaliser were all bolted into the Big steel tool box, its all dry inside and working well, the toolbox turned out to be a good idea.   Quote   As you likely know, lot of talk about when to start Active balance, IMHO there is no one rule for that, it depends on the Cell mix condition, typical charge current and the selected charge voltage for the system. I found that cells in all three 48V packs are fine with a 3.3v start, not the 3.4V or more as some "experts" recommend, in my case due to the lower full SOC and charge voltage. Yep totally agree Do you have any current limit settings on the charge controllers? It might not matter after your setup is finished. I have mine limited to 50A per battery bank, there is more solar power available and that works when its not so sunny, the CC will do 60A but I should change the 32A input fuse, pulled the Anderson plugs last night incase lightening hit the solar array. The equaliser Didn't wake up till late today, but it didn't run for long that I'm aware of busy with everything else. This might be different, the voltronic inverter is making the BMS read current incorrectly, the charge controller is ok with the inverter switched off and the BMS reads quite stable, been a while since I tried that. Between the 2 of these there is not much capacitance compared to the home built inverter that will soon be installed, will need the pre charge resistor in place then. Just realised the large capacitor in the Telecom battery charger is 9000UF 75v with a ceramic resistor across it, I have just switched on the DC breaker and never thought about the BMS handling that, one day I might not be so lucky.   Quote   I decided to try a 60,000uF CAP bank across the DC cables between the AC Inverter and the Cells and BMS, this made a huge difference to charge cutoff voltage stability and obviously residual low frequency noise. I wonder if there is another way to do this, filter the noise etc. We are in for a few more humid days yet, 2 aircons going today, I was cutting tall grass the other day, working in that stuff is nasty in these conditions.