Solar Trickle Battery Charger

[TLC]

Hi, Am needing some advice on a Solar Trickle Battery Charger. Do they work & has anyone got one that they would recommend? We think that they seem like a good idea just to keep the battery topped up but we would like your views.

 

[JeremyClarksson]

The small ones are probably not big enough to run an alarm if you have one.

We use a 13W suitcase type left on the seats with the skylight blind open - keeps the battery topped up with the alarm on, is useful when no EHU and can be picked up for

 

[Hugh_374319267]

I have bought a small trickle charger from Maplins for

 

[rob_jax]

TLC,

There are plenty of posts on Solar (or PV) panels - a search should reveal all, but in outline:

A lead-acid battery self discharges at a rate of around 0.5AH per day, and if you don't allow a battery to discharge below 50%, then a 100AH battery will need urgent recharging after 100 days.

The cheap solar panels - advertised in the tabloid press - seem to have an output of under 2 Watts - that means a charge current of 0.1 Amps for the hours that the sun shines. In winter, at the very best, they will supply around 0.3AH - better than nothing, but you're not winning. These cheap panels may also be supplied without a "blocking diode" - and will discharge the battery during the nights.

The better solar panels - with a rating of 10 Watts or so - and only a bit more expensive than the cheap panels - will provide almost 1AH of charge each day - and will happily keep the battery in tip-top condition. And also run a small alarm or other low current drain on the battery. And they have a blocking diode as standard.

"Real" solar panels for wild camping (no EHU) are rated at 40 or 80 Watts or more and require charge controlling electronics to limit the power fed into the battery. You don't need to go there.

Suggestion: Look for a 10 watt model - Maplin and other electronics shops have special offers on these devices from time to time.

Robert

 

[TLC]

Thanks all for your replies. I have just looked on Maplin's & think I will buy the suitcase type. The only pain is that it is not even shower proof so if it is caught in a shower.....ruined!! May take a look round for a waterproof panel.

 

[rob_jax]

You should be able to find a 10 Watt (or thereabouts) panel that is waterproof - and can be permanently mounted on the caravan roof. And you now need to feed the power cables through the caravan skin - it's not worth going to all the expense and trouble for a low power panel - but if you were thinking of a higher rated panel for extended "wild camping", then it's essential.

However, the type that aren't guaranteed waterproof are fine for use inside the caravan, placed close to a window that receives direct sun-light. The acrylic window will reduce the efficiency of the panel - but not too much.

Robert

 

[JeremyClarksson]

I have the Maplin type (x2) and was not aware it was not showerproof - it has seals on the connection block and that is the only thing I can see water getting into.

Ours has been out in heavy rain quite a few times and has shown no sign of ingress or corrosion.

I would not worry about it.

 

[Hedgehog1]

There is lots of useful info on my website www.naturesgrid.com - Don't order anything though as we have shelved the project for now!!!

TONY

 

[TLC]

Jeremy,

Do you need a regulator with the 13w suitcase type or has it an inbuilt regulator? I am just worried about the battery over charging.

 

[shaun_374336076]

I'd recommend that for any caravan owner - the entry level trickle chargers perfrom very poorly. Most of the entry level solar panels are manufactured from thin film (plastic) or amporphous silicon which only works for 5 years or so then degrades.

The entry level trickle charger needs to be a 10W rating and above for longevity you should purchase a monocrystalline solar panle these are typically guaranteed for 25 years to produce the rated output less 20% which is great pay a little more get something that lasts and can be moved to your next van.

For weekend and 2 weeks wild camping and caravanning you need to be looking between 30W - 55W for a solar panel that will operate and actually put back up to 3-4 amps per hour - a geally green energy battery charger with enough amps to make the purchase worthwile.

My adviuse for what its worth dont waste your money on entry level plastic solar brief cases and trickle chargers buy a ce, tuv and iso approved panel made of monocrystalline solar cells that will last a lifetime.

We purchased a 51w panel from Free Solar Energy Uk a specialist in Caravan, motorhome, camping and narrowboat 12v battery charging. There web site is here but it looks like a lot of the great products are out of stock till Jan 08 due to the christmas demand http://shop.freesolarenergy.co.uk. I found these people to he honest, value for money and you could call them for fee advise.

 

[JeremyClarksson]

TLC

Sorry missed your question.

It has a blocking diode but no regulator - it does not really need one.

 

[JeremyClarksson]

Slight correction - Some 13W briefcases do come out with regulators now.

http://www.maplin.co.uk/Module.aspx?ModuleNo=99760&C=newsletter&U=07P13-3&T=11992404