If all else fails you could always bring home the batteries and charge them up with a battery charger like one of these:
http://www.batterychargers.com/itemlist.cfm?cid=2
I have one and sometimes use it to charge our extra 12V battery (that we use for the TV/DVD) before trips or if I just want to quickly charge the TM Trojans (we have two 6-volts too, the T-105's).
I think I paid about $70 for ours at the "W" store.