Solar Charge Controller and High Battery Voltage.

[DJE]

Just noticed today that the battery voltage was 15V and it's never been that high before. There is a single 50W panel on the cabin top to keep the batteries topped up. The solar charge controller was flashing its "battery full" light. When I ran the water pump for a while the voltage quickly dropped to about 13V. The boat is ashore and the engine hasn't been run for months. The batteries are at least seven years old and have been giving cause for concern so I'm on the point of replacing them anyway. Could old batteries cause the controller to misbehave? It's a cheap PWM type and when I replace the batteries would it be worth getting a better controller?

 

[Keith-i]

Sounds like the controller at fault rather than the batteries. I’ve just bought a Votronic MPP165 which comes in a marine version with coating on the circuit board to protect against corrosion.