Solar panel low charge current

[kalli]

Hey all,
first trime p[osting. T25 in Ireland. Have the camper for 2 years already bvut leisure battery ran empty and I checked the solar installed by previous owner. System is either 120W or 240W. looks exactly like this with same panel measurements: https://www.amazon.co.uk/ECO-WORTHY-120W-Monocrystalline-Solar-Panel/dp/B08SVX7W9X?tag=mhf04-21

the charge current is always very low, even with a low battery. evenings 0.6A, during bright summer day max 1.3A

I measured voltage on panel, which is 17V, which is also connected to charge controller and battery is at 12.8V at this moment (after i charged it). but like I said, I never saw more than 1.3A

to me this is 12V*1.3A =15W - I was expecting 10A best case, hoping 5 during day if its a 120W and double that on a 240W panel

am i wrong, does this sound normal?

 

[oldiesontour]

Do you have one panel (120w) or 2 panels (240w)
If one panel flat on the roof 120w on a good bright day may bring in around 80w on a cloudy day next to nothing ( my 440 w panels haven't gone above 1.5 a today) also you have a cheap PWM controller rather than the moe efficient mppt

 

[Tombola]

Hi And welcome to the forum.
10a in winter/autumn in the UK is very optimistic, you wont get that with 120w panel especially with a PWM controller, MPPT is the best bet,
can you clarify do you have 2 x 120w panels or 1

 

[TrudeandDall]

Based on your panel sizes, your expectations of 10/5 amps are about right for a good clear and sunny mid summer day.
I have 280w panel with a quality MPPT controller and even in high summer I never get the 20 amps that in theory my system can produce - 15 amps, on a good day is realistic.
But it's winter now, there is not much usable solar energy in GB and Ireland, so what you are generating at the moment sounds about right for this time of year.

 

[donkey]

Disconnect the panel(s) and connect directly to a meter set to dc amps. Expose the panel to full sun and you will get the true output of the panel. If you can gain access to the rear of the panel, the data sticker should show the short circuit output in amps.

Geoff

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