Solar Panel without Leisure Battery?

[paulo999]

This summer I'm going to be in one place for two weeks.

At the moment I don't yet have a leisure battery.

I've estimated my power draw for the two weeks and I think it'll be more than a decent leisure battery can offer, at least one that will fit under the passenger seat.

So, my thinking is: Get a big solar panel. I'm looking at 100w, which apparently should put out 50w if it's overcast. That's 300-400w/hrs a day, which should easily keep up with my anticipated 200w/hr use a day. Peak draw will be during the day, which means that it won't discharge as deeply as if say, all of the draw happened in the dark.

So now I'm thinking, can I cut a corner here and skip the Leisure battery? How deep discharge can traction batteries tolerate? Or is this a bad idea for other reasons, regardless of discharge?

[jamesc76]

you need to add a battery to it, if your only using a little power a day you could use a standard car battery.

[paulo999]

you need to add a battery to it, if your only using a little power a day you could use a standard car battery.

That's kind of what I mean - use it to feed the regular battery.

[eatcustard]

Not recommenced, I would stick in another battery, just in case you flatten your starter battery as what a solar panel says and what it does is a different matter.

Traction batteries are the dogs dangles, and can handle quite a deep discharge

[kevtherev]

I agree a traction battery would answer your question and do what you wanted.
but they are not cheap
However they last for ten years instead of five, have twice the amphour capacity of a similar sized leisure.
Last over ten times longer after a full charge

[jamesc76]

you need to add a battery to it, if your only using a little power a day you could use a standard car battery.

That's kind of what I mean - use it to feed the regular battery.

No mate for the amount you recon your gonna use an other battery to act as a buffer (ie gives out 12v, as solar panels can kick out upto 18~19v in good sun) to the solar panel, plus make sure it comes with a solar controller! (saves overcharging and gassing the battery!)

[fodtommo]

This is an interesting thread for me - I dont have an LB currently (its a leisuredrive so no frills spec!)I too was thinnking of popping in a car battery rather than a proper leisure battery (im well known for being tight ad I have an ok one kicking about!), even if its just for this summer, the only things we would run are 2 x flourescent lights and occasionally the radio / dvd player there is bugger all else fitted (leisuredrive again)and you wouldnt use the fridge off the battery when stopped anywa, got gas for that.

I did a trial recently, spent the evening in the van from 6 till 1am drinking beer with mates - someones gotta do it and checked the voltmeter at the end, we had lights and radio on and battery was down from 12 to 11 volts. which indicates to me that my kit does not require much.

Also I have a couple of old towbar twin electric kits knocking about - do they have a split charge relay i could pinch....being tight ...

Finally - I reall like the idea of a solar panel, whos got one, what do you all reccomend. can they be a permanent fix on the roof or is it a hang it out when stopped job??

Thanks

Tom

[paulo999]

Cool. Thanks for the advice folks - that's given me a few options.

(Already had the regulator in sight. Will probably try to overspec the amperage to allow for a possible extra panel at a later date).

[jamesc76]

I have a 48watt panel on my roof permanently mounted and been on a couple of years now brill bit of kit!

[ninja.turtle007]

I get up to just over 4 amps from my panels which are permanently fixed to my poptop. They work very well even though they are old. As the van isn't being used too much recently I found after a couple of weeks or so the starter Battery has being going flat. I have crocodile clipped a fused cable from leisure pos to starter pos to keep it topped up. This is removed before starting.

[paulo999]

I have a 48watt panel on my roof permanently mounted and been on a couple of years now brill bit of kit!

I have to say, the whole magic of 'free electricity' does appeal. I know it's not new, but it's still slightly sci-fi.

I was pipe dreaming the other day, about making the van self sufficient when stationary. With a 12v microwave for hot food and drinks, I think it's almost possible. There's room for *alot* of wattage on a hard top.

(I'm having a mid-life wannabe new age traveller crisis )

[ninja.turtle007]

I have a 48watt panel on my roof permanently mounted and been on a couple of years now brill bit of kit!

I have to say, the whole magic of 'free electricity' does appeal. I know it's not new, but it's still slightly sci-fi.

I was pipe dreaming the other day, about making the van self sufficient when stationary. With a 12v microwave for hot food and drinks, I think it's almost possible. There's room for *alot* of wattage on a hard top.

(I'm having a mid-life wannabe new age traveller crisis )

You will need a load of storage.

You could always collect the gas from your porta potti and use if for cooking!!!

[jamesc76]

a 12v microwave for hot food and drinks, I think it's almost possible.
(I'm having a mid-life wannabe new age traveller crisis )

Sorry but ya cant have new age traveller and microwave in the same post

[paulo999]

a 12v microwave for hot food and drinks, I think it's almost possible.
(I'm having a mid-life wannabe new age traveller crisis )

Sorry but ya cant have new age traveller and microwave in the same post

Err, good point.

[paulo999]

So, a quick update.

The panel has been out and about at a few events now. Two weeks at Glastonbury, plus some long weekends elsewhere.

I've still yet to mount it, so it's getting rested on a bumper (meaning it goes from being perfectly angled, to being entirely in the shade.)

In terms of power, my laptop is outpacing it at the moment, which means there is some net loss on battery when that's in use. For other stuff (lights, phones, stereo) it's seemingly limitless.

And, having not got round to a leisure battery set up, it's all running via the main battery. Which now fires the starter better than ever - seems like only two cranks and the engine is alive.

So maybe - just maybe - my theory is holding up. Partly. If one's main electricity use is during daylight, there's not much draw down on the battery, maybe none if you're using less power than the panel is putting out (mine's theoretically 100w). So the benefits of a leisure battery are hugely reduced.

The gotcha is the laptop. The net loss from running that means one *is* hitting the starter, which is obviously not good. The inverter fires a low volt alarm after about 90 mins. At which point I switch off. Whereas if I had something that would be happy with deep discharge, I'd happily drain it a fair bit more.

So, project continues, but my corner cutting hasn't been a disaster - yet.