Help required with 12v issue.

[bigguspeckus]

We're currently in Southern Spain, lots of sunshine.
We have 2 SPs, (both flat on the roof) 80w connected to the Sargent Unit which is showing max output of approx 0.5 amps ☹ and a 120w which I fitted masen hooked up to a Fangpusun controller which is maxing out at approx 3.5 amps.
The Sargent Unit is indicating L batteries at 12.5 volts & 45%amp/hours and the Fang is indicating 13.1v & 78%amp/hours.
The 2 units are not inter-connected but they're hooked to the same batteries.
Is the discrepancy instrument related or am I missing something?
I'm fairly well genned up on AC electrics but my DC knowledge is pretty woeful and all things Solar even worserrerrer.
Any helpful comments would be much appreciated,,, and any unhelpful comments would also be nice...
Ass nice ter'be noticed, innit.
Best regards from down ear in the Sarff.
??

 

[pappajohn]

I would say its the Sargent unit at fault.
80w @ 0.5a as opposed to 120w @ 3.5a

3.5a is far more realistic as is the voltage @ 13.1 and ah capacity.

 

[bigguspeckus]

I would say its the Sargent unit at fault.
80w @ 0.5a as opposed to 120w @ 3.5a

3.5a is far more realistic as is the voltage @ 13.1 and ah capacity.

Thanks for taking the time to respond PappaJohn. I think the 80w SP is knackered,,, I'll measure its output direct from the panel and take it from there. ??

 

[Lenny HB]

Get a multimeter direct on the batteries that will give you a true reading. You could then try disconnecting each panel and see what happens to the voltage.
Let us know the results then we may be able to suss out what is going on.

You could also swap the panels over to the opposite regulator to see if a regulator has failed.