I recently purchased a BSC IP67 12/25 charger that is exhibiting similar symptoms. It is running the 3.65 firmware and the serial number begins with HQ2444.
In Storage mode with a 92 AH AGM battery and no load, the current spikes by up to 3 A every 15-20 seconds. The voltage jumps from 13.27 to 13.52, then declines and jumps up again along with the current. If I add a load of 1A, the output stabilizes. Here is a screenshot
I assume this is not normal. Is the 3.67 firmware likely to fix this problem, or is this a hardware problem?
I am observing the voltage and current with a SmartShunt.
Thanks for your help.