question

roger avatar image
roger asked

Solar controller not putting out full power

  • Hello I have attached a 100/50 controller to a 600ah 12v lifepo4 battery bank. And am charging that with 1000w at 40 v.

I put a clamp meter on the the cables and I know the batteries are a bit low yet it is still only putting in 15 amps. I have also a 24v set of 300ah these are doing a bit better but I still don't believe that I'm getting everything out of my panels and in to the batteries.

Any ideas please


solar sizing
1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

bibbjs avatar image bibbjs commented ·

This sounds like the same issue I am having. I have Victron Gel batteries and a 200W system on a 75/15. The max I am getting is 1 amp.

0 Likes 0 ·
4 Answers
JohnC avatar image
JohnC answered ·

Hi Roger. Piease measure your battery V. Your cc will back off once that's achieved. Your cc may well have come with default settings of like 14.4V Absorb. And may not suit your Li's.

First port of call...


1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

roger avatar image roger commented ·

Yes I did check my battery voltage and it was very low only around 12v. I will have a go today using Bluetooth on the phone to see what I can do. Any tips would be appreciated.

Thanks from Roger

0 Likes 0 ·
Guy Stewart (Victron Community Manager) avatar image
Guy Stewart (Victron Community Manager) answered ·
Try isolating your panel strings to make sure that each is putting out the correct power, voltage and polarity.

It might be a solar wiring issue.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

roger avatar image
roger answered ·

Both 12v and 24v are running completely separately.

I am getting a worse result from these controllers than from some cheapie.

I get the feeling some settings are wrong, it worked well yesterday in the hot sun all day but at the end of the day there was still not much left in the batteries,.

I am also taking a lot out of them but am alternating between the the two sets and theoretically there should be plenty of amps there.

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Can you seperate out the panels to see how much power each panel or panel pair is putting into the system independently of each other panel?

We want to see the production and voltage from each panel/pair individually.

For example if a panel is connected in reverse polarity it will be hidden by the others that are correctly connected.


I am not sure what you mean about 12V and 24V, do you have multiple battery banks connected to the same MPPT, or you have tested the MPPT in 12V and 24V systems?

0 Likes 0 ·
roger avatar image
roger answered ·

Yes they are totally separate 12v and 24v.

Its basically another system that I can turn a switch and run from one to the other, separate inverters as well. No link.

I think my next move is to get hold of a Bluetooth dongle and make some adjustments. To set up to the battery manufacturer specs.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Additional resources still need to be added for this topic