# leisure battery solar panel

Discussion in 'The Beginner' started by jgee, May 21, 2012.

1. ### jgeeRead Only Funster

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puchased a 110 amp battery now want to buy solar panell does it have to be matching ie 100watt or could i buy abigger one say 150 watt would it be worth it paying extra for the bigger panel

2. ### stcyrFunster

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Bigger the better!

3. ### stcyrFunster

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At the moment we have a 50w panel and an 80w panel feeding 1 x 100a battery... the bigger the panel(s) the less time it'll take to charge the batt(s). On our previous MH we had 1 x 80w panel and 2 x 110a batteries... Both worked well and kept us going fulltime.

4. ### hilldwellerFunsterLife Member

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Spot on.

There is no correlation at all between Ah or battery and watts of solar cell. They are two totally different units.

The 100W panel is almost fiction, 99.99% of the time it will output nothing like 100W.

100/12= 8 Amps in bright sunlight with the panel angled at 90 degrees to the sun.

If you wanted to be accurate you would be saying "I need 70Ah power a day so that is 70x12=840 watts per day. If I guess 4 hours sun a day, 840 / 4 = 210 watts. Now allow 50% for less than perfect sun, you would need 420 watts of solar panel."

Trouble is assessing that 70Ah ( or whatever it is ) a day.

We manage 4 days easily on 110Ah, of which we use 50% so I believe we use 55 / 4 = 14Ah per day or 14*12 = 168 watts per day. 168 / 5 sun = 33, double it for luck and an 80 watt solar panel would do us nicely.

But as winter approaches, forget the 5 hours, so just as Stcyr said "the bigger the better", but now you have an idea why.

5. ### GromettFunster

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When it comes to a choice between 80/100/150 watts solar panel total wattage more is always better.

However 2 x 80 watt panels will be cheaper than 1 x 160 watt panel.

You can get 80 watt panels for around the £100 mark.
120 watt panels are about £160-£180.

Hilldweller you are complicating things again:Wink::BigGrin:

I work on the rough guidelines. Aim for the same watts in solar panel as you AH of batteries. Allowing for budget and roof space of course.

I have 500AH of batteries and can't physically fit 500Watts of panel on my roof unfortunately. However 240watts gets me a good run for my pennies.

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plus a genny

...... plus he adds the genny:Rofl1::Rofl1::Rofl1::Rofl1:

bob

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