Can i run 12V DC=0.5A DSL Modem on 12V=7Ah Battery???

[Kapilkaps]

Can i run 12V DC=0.5A DSL Modem on 12V=7Ah Battery???

 

[Gryd3]

Can i run 12V DC=0.5A DSL Modem on 12V=7Ah Battery???

You sure can, but there are some things you should consider.
Mainly... be careful choosing the right battery. Most SLA (Sealed Lead-Acid) do not like to be fully discharged... it causes them to degrade and fail.
You may also find that as the battery drains, the DSL modem may, or may not become unstable as the voltage dips... This is highly dependant on the design of the modem. Expect it and plan for it, but don't place any bets