I think to answer this properly we woud need more info on the battery.
i'm planning to setup a headunit in a waterproof box to run outdoor speakers. i have a 12v 6amp adpator and have bench tested it and it runs fine off the adaptor. now since the box is going to be outside i dont want to have it always plugged in (when not in use) so i figure i'll put a 12 volt lead acid battery in it. all i want the battery to do is pretty much keep all my presets and everything set while the system is unplugged. the question i have is the adator i have going to be too much power to charge the battery? and/or will the voltage be not enough to charge it? again i dont plan to run the system off the battery i just want it to keep all the presets and everything.
like those alarm batteries radio shack sells...ex:
2003 Steel Blue PT Cruiser GT Autostick, Mopar BOV, K&N FIPK, Dual Exhaust, Boost Gauge.
ICE: 2 12" Infinity 1230W, JBL BP1200.1, Infinity 6000CS, JBL P80.4, Sirius Starmate.
I suppose the problem I can for see is 1. over charging and 2. making sure you get a battery heavy enough handle a 6 amp charge. Such as the first one. Might be easier to rip apart something that has a 12 volt battery w/ a power adapter and internal components that prevents over charging. ( I think like a UPS at which point you could use 110v and not 12 ) but that would take up both room and time.