So, over the winter when not using the boat much I have been keeping battery at 13.0 VDC setting for storage mode, 14.6 for bulk, and 13.7 for float with offset of 0.1 V for re bulk (float). Re bulk (float?) every 7 days to get BMS to do a top balance. Any comments on this protocol for a non Victron LiFePO4 200 AH battery?
First thing is it isnt doing is a repeated absorption every 7 days ( where it is set) even though it thinks the battery is at or below 13.0 volts per the status reading on the connect app?
Also when voltage showing on the Connect App is below the set 13.0 volts storage (12.9 but meter directly at the battery showing 12.7) and re bulk method set to voltage, and offset set to 0.1 the charger is not "re bulking or charging to the 14.6 absorption setting even thought battery is 0.1 volts below the re bulk voltage? What setting is the "re bulk voltage? The absorption setting or the float setting?
I use Bulk = 14.2 volts and Float = 13.5 volts when my RV is in storage. I’ll bump those up to 14.4/13.6 when the RV is being actively used. There is very little state of charge increase between 14.4 and 14.6 volts.
I’m working on projects in my RV in the winter, plus I have warming pads on the LiFePO4 battery, so I need the battery fairly charged up.
BMS are usually configured to balance cells at a cell voltage of 3.4 volts, which is 13.6 volts for the battery. So while balancing doesn’t happen that often in storage I’ve never seen my cells go out of balance in that timeframe.
Thanks for info. What I know from the limited data on my battery is that it says charge to 14.6 volts and they sent a cheep 10 amp charger with the battery that charges to 14.6 and then shuts off. No other data on the battery other than its 200 AH and has 4 cells and a built in BMS. I ditched the cheep 10 amp charger last year and installed a Victron IP22/12-30 and have been trying to figure out what to set it to ever since . I am now at 14.6 absorption, 13.7 float, 13.5 storage, re bulk method = voltage, re-bulk offset = 0.10V, absorption duration = adaptive, tail current = disabled, repeated absorption = every 7 days. It is holding the battery at 100% SOC but when it finally drops 0.10V below the 13.5V from small parasitic loads on the boat it doesn’t re-bulk and doesnt repeat absorption every 7 days? Otherwise the cheep Chinese battery is doing fine after 5 years in use! I whish there was a pre set setting for a 12.8V non Victron LiFePO4 battery in the connect app, it would be so much easier!
Also, how do you know that your cells haven’t gone out of balance? Can you read the individual cell voltages from your BMS via a app?
Yes, the BMS I use for my battery connects to an app on my phone through Bluetooth where I can see the voltage for each cell.
You could take the battery apart and replace the BMS. I’ve seen people do just that.