Adding More Solar than 160 Watts

[alanmalk]

Originally Posted by Vermilye

It seems to be a new development - in the past I've been able to leave the portable panel connected all day; now I have to unplug it when the GoPower controller decides the batteries are full.

At this point we have to ask "what changed"? Was working, now it is not.
Everyone loves a mystery - or do they?

--
Alan

[KirkB]

Jon, have you tried the Max Power Boost function on the Go Power controller? (press A for 5 secs). It might keep the controller at 14.4 V for an extra 1/2 hour longer, once it has switched to float mode.

There is a warning in the manual not to use this more than twice a day to avoid gassing.

[Vermilye]

Unfortunately, I have the older version of the GoPower controller without the "Maximum Power Boost feature.

I understand that the controller is using time to switch to float rather than the actual charge on the batteries, but I don't understand why adding a panel will cut down the current when in the float mode. If it stayed the same with the addition of a 160 watt panel, I expect the controller is limiting the current, but why does it drop to 0 amps with the addition?

[alanmalk]

Originally Posted by Vermilye

... but why does it drop to 0 amps with the addition?

This might take a lot of detective work with a volt/amp meter.

Here is the key question: "What is even stranger is that if I unplug the portable panel, the GoPower controller jumps the current back to 2-3 amps of charging current".

Questions - in no particular order:
Where is the unplugging/plugging taking place? Can you confirm that the wires
from the portable panel are still attached at the input to the GoPower? Unlikely,
but possible that at some point they were moved to the output side, which could
go a long way to explaining what you are observing.
Can you measure the voltage at that point before and after the plugging?
Can you measure the current - if any - coming out of the portable panel after plugging? Coming out of the GoPower (to verify the 2-3 amps)?
What is the voltage - using your voltmeter, not the GoPower - at the output terminals of the controller, and at the battery posts directly?

All these answers may or may not help. This is a good project to use up a cold, dreary mid-winter weekend.

In an ideal world you would substitute another GoPower in place of your current one and see if the behavior changes or remains the same.

Wether or not you settle on a definitive answer, you will be an expert at troubleshooting solar systems when you are done.

--
Alan