Solar panel not charging - advice wanted

[chearmstrong]

Hi,

I have a PV Logic MPPT Pro Dual Batter Solar Charge Controller.

It no longer seems to be charging the battery. I’ve connected to the unit via Bluetooth - it says there is no charge available and I’m not sure why. I have checked the wired connections etc.

Any ideas on what to check? Is the panel broken or could it be something else? The attached screen shot shows the panel is generating energy (I think). But not charging the battery.

Thanks in advance.

 

[Dellmassive]

Get a voltmeter.

Take both the red and black solar wires out and test.... during day with strong sunlight.

Take a pic.

Also a pic of the solar panel.

Your pic is showing 11v.... Which is not enough.

What size and spec solar panel have you got,?



.






.

 

[chearmstrong]

Get a voltmeter.

Take both the red and black solar wires out and test.... during day with strong sunlight.

Take a pic.

Also a pic of the solar panel.

Your pic is showing 11v.... Which is not enough.

What size and spec solar panel have you got,?



.



View attachment 161524


.

I'll give this a shot today as I have a voltmeter - I'm not sure on the exact spec as it was already fitted when I got the van. Will take a pic and measure it up though and report back. Thanks.

 

[Dellmassive]

a few pics of the panel will help. . .


but normally a 100w panel should show 19v ish.

 

[chearmstrong]

OK, so this is strange... Just gone out to check this and it seems to be charging this morning. Nothing has changed but it looks OK from what I can see. It's weird as we were away at the weekend and the battery went too low to power the internal lights/USB etc. It must have had some power as the fridge was running still - it was just cutting off the lights. Yesterday morning was really sunny and it wasn't charging - we had he same issues the week before too.

We normally don't use our EHU and tend to only rely on the solar - I was wondering if we've just been hammering it too much and not giving it a chance to fully charge? We've been away a lot recently (including doing the NC500 and a trip to wales - all without EHU).

I will continue to monitor it - I'm also going to connect the EHU.

 

[Dellmassive]

that panel on the roof looks like a 50w ish going from the size . . . .


which is well under rated for the loads you have mentioned. . . USB/Lights/Fridge.


though the readout does show 15.96v from the panel - which is good.

but is only showing 4.63w of charge power - which is next to nothing. ( but assuming there isnt direct unshaded sun at that point as your pic shows the panekl as shaded. )


++++++++++

a 50w panel might just give enough power to prevent a standard battery from self discharge. . . it scertainly wont run a fridge and usb chargers and LEDS.

look at adding in some mobile panel too beef you you solar yield. .


look at 150-300W to run what you have.


more info here - [Guide] Mobile Solar Panels ? . . . - How I Did It -

++++++++++


also worth noting that temp can effect panels . . . it might go faulty when hot? ( thermal expansion causing a fault )



++++++++++

 

[chearmstrong]

Thanks @Dellmassive - that's really helpful. Thanks for the help. I'll look in to this - I wonder if it might be worth upgrading the roof panel at some point too. Cheers.

 

[baggiero]

That (heat making a circuit break) is what happened with ours - and I concluded (by some rather clumsy experimentation with cardboard shading of half the panel at a time) that ~11V was the max from "half" the cells and that one half had gone pop.. (i.e. when the busted half was 100% shaded it made no difference to the voltage ...). Cold mornings would see the solar voltage rise beyond 14V and give a bit of charge but once it warmed up, it would drop back to 11V max ...
Bad news is, it looks like that lack of voltage combined with the Dometic CRE50 fridge cut-out threshold voltage level of 10.4V (why!?) has knackered our leisure battery .. (assuming that's what the dramatic drop in voltage when the fridge kicks in means..)