Question about batteries

[Anonymous user]

I have a Back-UPS XS 1300 that only gets about 3-5 minutes of runtime fully loaded. Since the batteries are getting a bit old, I was wondering what would happen if I replaced them with a giant Marine/RV deep cycle battery with 80 Ah (and the appropriate voltage). I realize this would void my warranty and such but I'm curious to know if it could work. Would the charger in the UPS be able to charge such a large battery? Would the inverter be able to hand the longer runtime without overheating? Is there anything else that could go wrong?

[Techie_apc]

Ben,

APC does not recommend to connect a higher AH battery than the actual AH battery to the UPS. The UPS is ONLY designed to support its battery which came with it. The UPS charger will fail or it will cause abnormal results if you connect the higher AH rating battery to the unit. Secondly, it will not meet the UL standards.

[BillP · Accepted solution]

as techie mentioned, the charger on these units is designed for the included battery and its amp hour rating. so, charging will take a lot longer on this unit since the UPS charger is I think maybe 5-10 watts. then also, you just need to make sure you wire it up for the correct voltage. i think this uses a 24v battery?

as you mentioned and realize, it does void the warranty and APC cannot support the unit further if modified in this way but as long as you take into account the above information, it may work.