How to check whether a charge controller is broken or not

[carolinabigfoot]

When my fla-battery bank died recently the charge controller (a Morningstar ProStar PS-30M Gen2)
was charging bulk while the bank was literally boiling. (I disconnected the panels right away and
haven't hooked them up ever since.) I wonder now whether I can still trust that charge controller
and if there is a way to test whether it is broken or not. The battery bank was definitely done for. It went from
green on the charge controller to low voltage disconnect in within a few hours with no loads attached to it except
the charge controller. Any ideas anybody?

 

[MisterSandals]

was charging bulk while the bank was literally boiling.

I had this happen once and it was because my batteries were shot. They could not charge up to the voltage that would normally stop a charge controller from pumping more energy into it. So, without a temperature probe, the charge controller just keeps charging, not knowing or caring why. And, all this energy, that normally produces a chemical reaction in a good battery, is absorbed and heats up the battery.

If you have another way to charge your batteries and find that your batteries do in fact charge to full and hold that charge above nominal voltage, then you can rule out the batteries as being at fault.

My gut feel it is your batteries that are the problem, not your charge controller. If your batteries are new and not "supposed" to be failing yet, then that should be figured out. Were they abused or just faulty?

 

[carolinabigfoot]

The bank was 5 or 6 years old. It had started to consume more water in the recent months. In the end it went down fast, draining fast
after dark and "charging up" fast when it got light again.

 

[MisterSandals]

The bank was 5 or 6 years old. It had started to consume more water in the recent months. In the end it went down fast, draining fast
after dark and "charging up" fast when it got light again.

They dead.

 

[RCinFLA]

When my fla-battery bank died recently the charge controller (a Morningstar ProStar PS-30M Gen2)
was charging bulk while the bank was literally boiling. (I disconnected the panels right away and
haven't hooked them up ever since.) I wonder now whether I can still trust that charge controller
and if there is a way to test whether it is broken or not. The battery bank was definitely done for. It went from
green on the charge controller to low voltage disconnect in within a few hours with no loads attached to it except
the charge controller. Any ideas anybody?

All it takes is one cell in one battery to go short or low resistance to cause the rest of series cells to boil.

Charger is just trying to get to absorb voltage. It has no way to tell one cell is shorted. Some chargers have a maximum timeout limit setting for absorb to reduce the damage for a situation like this.

 

[carolinabigfoot]

Thanks for the replies.

 

[circus]

Probably only one battery is shorted (turns into a heater). It'll suck the the remaining batteries dry making them all look bad but they're not. Unless you waited too long to fix it.