Best Kind of Charger to buy?
 

Hi all,
I'm not using my R50 very much at the moment and the alarm has burnt through two batteries already when it's been sat on the drive.
I had a third put on recently but it's already two weeks since it was last used
I don't want to ruin another battery... Would "maintenance charging" with something like this be sufficient to keep the battery in good condition or might it need something meatier to charge it back up?
Thanks in advance