I recently bought a budget-friendly MPPT charge controller and the instructions are poorly translated, making it tough to understand. There's only one voltage setting I can adjust that ranges from 13.7V to 14.6V. I'm trying to figure out if this setting corresponds to the float, bulk, or absorption charging mode. Right now, it seems to keep my lithium battery charged at 100%, according to my Victron shunt.
Here's my main concern: My battery's full charge voltage is 13.7V, so I'm worried whether charging it at 14.2V (the default setting on the controller) is safe. I've read that too high of a float voltage can damage lithium batteries, although I believe the BMS should protect it. Still, I've found so much conflicting info online that I'm really uncertain about what's safe or appropriate. Can anyone help clarify this?
1 Answer
For a LiFePO4 battery, 14.2V is actually a pretty good charging voltage. When I worked with 12V systems, I often set mine around 14.1V. The 13.7V setting is on the low side but should still keep you safe. Just keep an eye on the battery health over time to ensure everything's working well!
If the charge controller treats 14.2V as a float, it should be okay, but consistently staying in that range could wear your battery down faster. It’s good to check your battery’s specs to confirm!