I have a solar panel (100 watt, 18 V, 5.5 A) hooked up to a Victron BlueSolar PWM Charge Controller (12V, 5A) to charge a Victron AGM 12V/8Ah Deep Cycle Accu.
It is a very small set-up, just for me to get some hands-on experience with solar panels and batteries.
All looks good and works fine, but the Charge Controller says the voltage during loading is 13.1 V (and the current is around 2 A). Should it not be at 14.4 V , as per specification on the accu? Is my battery loading at all this way?
This is the target voltage. It will take some time for your battery to reach that if it is starting around 13.1v
Think of the charger like filling a bucket. The 2 A is the water flowing into the battery, while 13.1 V is the pressure/level of the electrical system. As the battery becomes full, the charger raises the voltage, eventually reaching around 14.4 V during the absorption stage. After that, it reduces the charging current to avoid overcharging.
So seeing 13.1 V and 2 A does not mean the battery isn’t charging. If current is flowing into the battery, it is charging. The interesting thing is whether the controller eventually raises the voltage to the specified absorption voltage.
12V/8Ah that’s tiny battery so it should not be too long to full.
The battery is almost empty. The voltage will rise during charging an is limited by the charge controller at 14.4V. When 14.4V are reached the battery is not fully charged but the current drops down. After a few hours the charger should lower the voltage to about 13.6V (float). The battery is full charged if the current sinks to about 0.1A. It depends on the condition of the battery how long it takes.