What size folding solar panel for 110amp battery (1 Viewer)

[Urs4_2008]

No Problem! Maximum output for panel is just over 8 Amps which is poor for 200W and you will never achieve all of that anyway,

The panel has higher voltage. P=UxI. P=30.8v x 8.28 a = 255 watts. So it's fine regarding this.

 

[andy63]

I see we are back on the series parallel debate again...
A good while back when andy @Techno was contributing to these sort of threads i remember him doing an actual test ... it did seem to suggest that there was no gain in the series connection for your average mh install and id anything more to be gained with a parallel connection...
https://www.motorhomefun.co.uk/foru...lator-parallel-or-series.106170/#post-1380718
Have a read @Urs4_2008 .. theres always more than one way to skin a cat.... both work... depends on the circumstances.
Andy.

 

[funflair]

No Problem! Maximum output for panel is just over 8 Amps which is poor for 200W and you will never achieve all of that anyway,

Hi Philip

I guess there is confusion as the panel spec is just for panel as in the panel output not the output you would expect to see from the controller when it converts 30v to 12v the amps has to go up following the rules of V=IR.

Martin

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[Urs4_2008]

I see we are back on the series parallel debate again...
A good while back when andy @Techno was contributing to these sort of threads i remember him doing an actual test ... it did seem to suggest that there was no gain in the series connection for your average mh install and id anything more to be gained with a parallel connection...
https://www.motorhomefun.co.uk/foru...lator-parallel-or-series.106170/#post-1380718
Have a read @Urs4_2008 .. theres always more than one way to skin a cat.... both work... depends on the circumstances.
Andy.

Thanks, Andy63 I've done a lot of testing myself, along with several installations. I've testet a lot of different charge controllers. In smaller installations there are little to no difference (<200w). From 400w and upwards, the amperage rises to a point where it matters - specially regarding heat. 400 watts can generate ~25 amps. If you use a PWM instead of a MPPT controller, you can observe in a 400 watt solution upwards of 34 amps. Normal household wires and breakers are 10 amps and 16 amps.

So 34 amps is quite a bit, running from the paralell panels on the roof towards your PWM controller, in this "worst case scenario". I've tested this, and a 4mm2 cable running shortest possible route from front of roof to house batteries in front of the vehicle on a small motorhome, the cables get hot when batteries are somewhat empty or running a powerhungry inverter.

 

[Urs4_2008]

Hi Philip

I guess there is confusion as the panel spec is just for panel as in the panel output not the output you would expect to see from the controller when it converts 30v to 12v the amps has to go up following the rules of V=IR.

Martin

Funflair is correct

The actual amperage on the 12v side towards charging the battery from this 250w panel will be transferred from 30v 250w to whatever voltage the battery is at and 250w (optimal conditions). Following this, if you have a sufficient big enough (MPPT) charger, you can observe 250w/11.7v = 21.3 amps running towards the battery if the battery is empty.

If you have a ie a 800w solar panel setup, maximum amperes charging an empty battery pack can be as high as ~70 amps. At 70 amps you need to carefully regard both the distance between the charger and the batteries (keep it close ) and the thickness of the cable, as well as the breakers and the connectors. 70 amps is a serious bit of power.

 

[autoswan]

It’s a bit like the magic circle, it’s called the 12v circle and they are sworn to secrecy so as to keep us normal people in the dark so we can not do anything. Haha

the most I have to do with electricians is when I cut or bury their first fix cables when plastering

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