Check out my discontinuous thread here
I'm starting to put my off grid setup together finally. Looking to peel off ~ 200W of 24/7 power consumption, and have a power source if we have any planned or unplanned power shutdowns. My system will be 24V with LiFePO4 batteries that total up to about 400AH of storage. I'm going to feed...
diysolarforum.com
I too bought 4215bn because of the passive cooling and huge lugs. The ones I bought were newer units with LiFePO4 support built in. That said, I do not like their built in LFP settings, so I'm using USER as battery type. In my thread above there is a list of what settings I am using for a 24V system.
Can you confirm yours do not list LFP as a battery type?
Also, read up on mine getting stuck but a firmware update fixed the problem. Yours might be older units and not be plagued with the problem.