Good day,
So I saw the chart linked below, which shows that LifePO4 voltage for a 12V battery is actually far above 12V, which makes me wonder about the safety of connecting it directly to my boat fridge.
Also, strange that so many of these are marketed as 12V batteries when they don’t fall to 12V until 90% power depletion. Any comments?
Thanks in advance.
It seems almost like one would need a sort of reverse inverter to connect a LifePO4 battery to anything 12V. So I must be missing something…
It’s just fine. Mobile electronics have had to deal with 14+volts coming in from the alternator on your car to recharge the starting battery for decades. The “nominal” voltage of a 12V LFP battery 3.2V per cell or 12.8V. When fully charged and then allowed to rest, LFP batteries generally sit around 12.8-13.2V.
The chart is somewhat misleading. First of all cell/SOC relation is always specific to the brand/type of cell used. There is no fixed table for all types/brands. Second LifePO’s should not be used to the BMS shut off voltages. You should keep above that so 0-10% or 0-20% is not usable capacity if you care or the lifespan of your battery. As a matter of DC-loads you should look into the documentation of the device. There is no standard, 13,8 or 14,4 or whatever all loads will endure.
Great information, thanks. So it sounds like I can connect my 12V fridge directly to the LifePO4. And that the fridge can handle the little extra voltage, which is normal.
I have an Engel fridge. It can do 12V and 24V. 24V is much more efficient. Can you check the voltage range?