The battery taking that sort of current, says to me that some plates are shorted. Your battery charger if it is a normal transformer one, may well have overheated and shorted out some of the windings from getting so hot.

This will happen if a battery is allowed to be flat for any length of time. If it is a gel type battery, then if they do go flat, they must be charged with a special charger at a slow charging rate or it will kill it.

Here are a couple of links explaining battery types and problems:
http://www.mpoweruk.com/leadacid.htmhttp://www.solar-facts.com/batteries/battery-failure.phpIf the car hadn't been used a lot prior to you stopping using it the battery may have already been in a low charge state and leaving it for 3 weeks enough to discharge it.
Where I work from home I suffer from batteries having a low charge at times (there is nothing more annoying than going to use the car and not enough charge in the battery to start it) so I'm looking at putting a 10-20w solar panel in the car with a cheap charging regulator.
