Victron charger

[briwy]

I have one of these rigged to a Biard 100w panel

I have suspected for a while that either the panel or the charger are not working correctly so as the van has had the roof done and the panel had to come off I have wired it all up temporarily to a spare battery. Even in southern Spain last year the panel didn't seem to keep the leisure batteries topped up despite very little use.
So today its fairly bright, bit cloudy but a bit of sun now and then and I am getting these readings from the controller.
No load on battery, 0w up to 3w. Obviously the panel is working as it's showing 21.32v.


With load on the battery charging one of my drone batteries. 0w up to 6w. Battery voltage drops as there is load on it.


The battery is charged fairly well, left on a CT charger, so obviouskly there is not much requirenment from the panel but it does seem low and given past possible charging problems I'm loath to put it back on the van until I'm sure everthing is OK.

If anyone has a similar setup with the Victron controller I would appreciate some comparison readings which would show if it's all OK or not.

 

[MattBW]

Sounds very low for 100w but cloudy and shadows will greatly reduce the output. What is the battery state with nothing attached?

I have a small 50w suitcase one and in cloudy conditions it wasnt great but when the sun was out I was getting 2 or 3amps rather than 0.1. In low light I was getting about 0.5a.

If its very cloudy and the panel isnt pointing to the sun then 0.5a isnt out of the question.

Or your battery is full and thus its adjusting the charge accordingly.

 

[MattBW]

Can you put a heavier load on it and see what happens then?

 

[briwy]

Thanks Matt.
I have just put another flat Mavic battery on it, the sun has come out and it has shot up to 60w, 4.4a so looks like it is all ok so panel going back on.

 

[MattBW]

Assume thats +4.4amps rather than minus?

 

[Max-Felix]

As above - depend on the load and state of charge so sounds OK to me!

 

[briwy]

Thanks guys.
Before putting the panel back on the van I tried pointing it at different angles to the sun.
I know this is obvious but I was surprised at the difference it made.
Direct at the sun got the 60w. Lying flat on the ground in the same place dropped to 20w. Even having the panel at a small angle seems to help quite a lot.
If it wasn't for the hassle of something else to put in the van I would make the panel portable with a frame to angle it direct at the sun.