Hi guys, I m considering changing the battery to a bigger one so as to increase the backup duration. The battery that came with it is 12V 7.5 Ah. The battery I m planning to put is a 12 V 100 Ah. Now my question is, will the big battery increase the standby duration without overloading and damaging the hardware in the UPS.And will it charge the bigger battery? I have an APC Back-UPS ES 500 VA,300 Watts.And having the battery externally is what I had in mind.Thoughts please ?