Self -heated 12V 100Ah Power Queen battery in the test

LiFePo4 batteries are known for their long cycle life and safety. Unfortunately, charging is not allowed below 0 degrees Celsius. Fortunately, the company, Power Queen, provided me with two such batteries free of charge for my 24V off-grid solar system. In this post, we'll look at how they work and my capacity test. At the end, I'll open the battery and let's take a look inside.

If you want to know more about our experience with the Power Queen solar battery, read my full article. Otherwise, here is a brief summary of our experience.

After the technical data of the battery, there are brief notes from my side:

The voltage ranges listed in the technical specifications are marginal. I recommend a final charge voltage of 13.6V and a final discharge voltage of 12V. For higher discharge currents, you can also set the voltage to 10.8V. If the battery needs to be charged quickly, a voltage of 14.4V can be used.

Capacity test

Between discharge and charge, we can determine the efficiency of the lithium iron phosphate cell chemistry. In our battery cells, this is an incredible 99.77%! This does not include charger losses.

Internal structure of the battery

The first thing I noticed was that the cells are installed horizontally. That's not a problem. However, the battery should only be installed in this position in your vehicle or photovoltaic system if you don't know how the cells are integrated internally. The top of the LiFePo4 cells always has the positive and negative contacts, as well as a pressure relief valve. This valve must never be facing downward.

Im Inneren von LiFePo4-Zellen

The first heating plate is hidden between the BMS and the cells. The second heating plate is located at the bottom of the cells, i.e., the battery base. So, at first glance, it looks good.

Conclusion

I'm very satisfied with the capacity, the weight of around 10 kg, and the 100A charging and discharging current. The heater will have to prove itself in the winter. If there are any important tips, I'll post them on reside-heimwerken.de to name.