Calculating solar panel capacity

[GuitarPhotog]

I'm considering using PV solar panels to keep my battery charged when there is no shore power available.

My typical energy budget is about 6-10 Ah per day.

I have a 55 Ah deep cycle AGM battery so can "stay out" 3-4 days if I'm careful.

How much solar capacity (in watts) do I need to recharge my battery daily, assuming typical conditions?

Thanks

<Chas>

[bdosborn]

How much solar capacity (in watts) do I need to recharge my battery daily, assuming typical conditions?

There's two ways to approach this.

1. PV output calculations based on season, panel tilt, battery capacity, weather conditions and latitude.

2. How much do you want to spend?

You'll be pretty happy with anything 60 watts or bigger given your usage. We can start zeroing in on the items in approach 1 if you want to size smaller than that.

The very rough rule of thumb is 1 watt of PV per battery amp-hr capacity.

Bruce

P.S. I'd look at this package from eBay for two30 watt panels to make a 60 watt folding panel. It's more expensive per watt but it's great when you're parked in the shade. I made one and its my favorite set up.

DIY Folding Panel

[dreadcptflint]

2. How much do you want to spend?

Bruce

Bruce,

You make light of the situation but that is what I did. There is nothing wrong with pay as you go. My set up is working great and allows me to do everything that I want.

Matt