Solar Charging Leisure Battery

[andyp1]

Hi,
Maplins have a 13W Solar charging panel with Diode on sale at the moment (£49.99)

Would this be suitable for keeping my 115 ah Battery topped up when in caravan storage yard - I need to use Motor mover when i collect van.
I am assuming it will work without the need for a regulator ?

Thanks in advance

Andy

 

[Reg]

Why not try one of these as a "cheap" option?

http://shop.ebay.co.uk/?_from=R40&_trksid=p3907.m570.l1311&_nkw=12v solar battery charger&_sacat=See-All-Categories

 

[Tonyex]

Hi Andy
Not sure if 13w is enough particularly if there is no sun and it is overcast. I have a 45w cost £200 it works in any conditions and keeps battery charged when away and no hook up. It has a regulator to provide a trickle charge when the battery is fully charged and this stops the gassing and loss of electrolyte. Essential you ensure 12v fittings are switched off e.g. fridge, aerial amplifier, radio, and isolator for mover as I found to my cost. Do you have an alarm system that draws off the van battery? Batteries need 14v to be fully charged my panel does that. As you know van chargers do not produce this - see various articles in PC magazine. Hope this helps.

 

[Reg]

If you need a 45w charger to keep your battery charged up then it would seem that you have a problem.

Look at the figures 45w divided by 12v is 3.75 amps.
In theory if a 115ampH battery needs that sort of charge to maintain a full charge then it suggests that it is discharging in approx 30 hours
(115ampH divided by 3.75amps)
What have you got running when the caravan is in storage? I would guess that any alarm or tracker system would be drawing only milliamps when in standby mode.
If you there is nothing running then it would be more likely be a battery on it's way out. In any case if you give your battery a constant charge at that rate then you are likely to do it damage anyway even accepting that it will not charge at night and in low light.

 

[Tonyex]

Sorry I was not very clear. I have no problems with my battery. My solar panel enables me to use 12v tv and halogen lights while away and no EHU, and ensure I can use my mover. I store the van at home and using the solarpanel saves taking the battery out to use a charger in the garage. I have only had to buy one replacement 110a battery in 10 years!

 

[Reg]

Tony
Yes that makes a lot of sense but for a constant trickle charge in storage I personally would go for a 2 to 3 watt.

 

[RonD]

I agree with Reg.... if your battery is fully charged to start with, a small 2w solar panel will maintain that charge. It won't really charge the battery but will prevent it self discharging in storage by putting in about 70 to 80ma in daylight.
Ron