i have 2 smartups 1400 and the battery has failed in one of them. i was thinking of replacing the factory battery with sealed gel cell car batteries (so the gas isn't vented into my room) to gain additional capacity. it occurred to me that i might be able to hook the batteries (it takes 2, in series, to make the 24v required) to both the UPSs so they'd benefit from the increased capacity. if i wire the battery array to the 2 UPSs in parallel, it will preserve the voltage, but will this create an issue during charge time? the battery connectors are just + and - connectors so there's no special on-battery circuitry, and i was wondering if it will cause a problem if both UPSs try to charge the battery at once. will this just charge the battery twice as fast, or will it feed power from one UPS into another and damage them. if this will cause damage, does it help if i use two different sets of terminals (the batteries in question have 2+, 2- terminals)?