I have attempted to charge a new Renogy 200Ah Bluetooth LiFePo4 with a Blue Smart IP65 12/15 charger. The charger is set to the LiFePo4 preset. The battery initially told me that its capacity was 45.56% and the voltage 13.2V (as delivered). The charger is connected directly to the terminals of the battery. There is nothing else in the system.
When I powered up the charger, it did the initial test, the bulk indicator illuminated momentarily, and then switched to absorption. The charge rate was initially 1A at 13.2V and gradually decreased to 0.7A at 13.2V. After being left overnight to charge, the charger output was 0A at 13.2V. The battery capacity had increased to 46.86% at 13.2V.
I have repeated the process several times but the charger behaves the same way every time. It will not output 15A at 14.2V as defined by the LiFePo4 preset.
The charger firmware has been updated to v3.61.
Unfortunately, I have only one LiFePo4 battery and only one charger suitable for charging it, so swapping out for known good units is not possible.
Am I doing something wrong with the charger settings, for example, or is it more likely that the charger (or battery) is faulty?
Edit: I have since tried to charge a partially discharged lead acid battery using the “Normal” settings with some interesting results. It does the test, then goes to bulk, then flicks back and forth between abs and bulk ad infinitum. This seems to tally with the symptoms of a hardware fault I have read about on here.