12V Solar battery chargers.

[Colinevan]

As you will all know 12v batts need a lot of charging lol.
I recently have seen these on ebay..

http://cgi.ebay.co.uk/5-W-Solar-Batt...QQcmdZViewItem

Now then, does anyone use one of these?? i reckon i could leave my spare 12v race battery in the car and leave the charger on the parcel shelf and charge whilst my car is parked up at work. It doesnt discharge when the sun dissapears and can safely be left on all week if i dont use the car as its a trickle charger.

For a cheaper option, you can get these, but it does state on some ebay ads that they wont recharge a flat 12v, it will only maintain one. Hopefully the one above it is upto the job of charging low power batts.

http://cgi.ebay.co.uk/12V-Volt-Solar...QQcmdZViewItem

Anyones thoughts??

Col.