solar trickle charging

[Tiz]

Hi,

Has anyone any experience or advice on trickle charging a battery using a solar panel. We keep our van in storage and although we use it for approximately 90 nights per year there are periods when it is left in storage and the battery runs down. It's a 2008 van with an alarm, no other power usage whilst in storage. Currently I use two 110ah batteries one in the van, the other one being charged at home and switch them over every six weeks or so. The alarm needs to be on and functioning because of an insurance requirement.

It occurred to me (after reading an article in the current addition of Practical Caravan) that I could use a small inexpensive solar panel trickle charger; internally positioned in the van to keep one battery topped up thus saving the need to change batteries. I believe this type of panel has an output of only 2 watts.

PS we need a fully charged battery when removing the van from site to enable the use of the caravan mover.

Tiz

 

[ProfJohnL]

Hello Tiz.

You could save quite a lot of weight and the inconvenience of having to swap batteries, if you opted for a larger solar panel and retained just one battery. with a big enough solar panel, you might match the power usage of the alarm system, thus still find you have more than enough power left in the battery to use the mover.

You need to check to see what the power consumption, of the alarm panel is and choose a solar panel of about three times the power to enable panel to recharge the battery during daylight hours for the power used over night, and to continue to run the alarm during the day as well.

 

[lairdAl_374474951]

Hello Tiz.

I had a small 12v trickle charger that was bought for me as a xmas gift.

I have put it to the battery & its working fine,mind you the batterys need to be fully charged in the first place to maintain the charge.

You mention that you need to keep the leisure battery on the van to keep the alarm working ?

We have a 2004 swift challenger & the alarm has a built in 3.3Ah sealed lead acid battery that will last when charged for approx 9 mths depending on ambient temperature/initial charge.

Obviously the alam battery is going to discharge somewhat over time,& to fully charge that battery you will either have to fit a leisure battery or connect to the mains supply for a while to give the alarm battery chance to charge.

Have a look in your hand book to see if you can find the same,it'll save you lugging the batterys about from home to storage every six weeks or so.

Our van has been in storage since november last year & is checked every fortnight or so,& the alarm system is working fine.

Laird Al.

 

[JohnnyV]

My understanding is that a battery will lose about 1% of its total amperage per day, so.....

A 70amphr battery will lose 0.7amps per day, a 110 amphr 1.1 etc.

If you have an alarm system running this will also draw amps so you need to find out how many it is drawing so that you can work out how many amps you need to replace.

The solar panel output is calculated in watts - my small one gives 1.5w - to convert to amps divide by 15 - so 1.5w = 0.1amps (I think) multiply by the number of hours that the panel is getting daylight and you will know if the output is enough to counter the loss.

If the panel gets say 4hrs of daylight it will put back 0.4amps - if it gets 8hrs it will be able to put back 0.8amps (if you run two panels in parallel you will get double the result).

Hope this helps

Jon