Most inverter batteries are sealed lead acid. A lead acid battery provides a good rechargeable power reserve and the sealed ones don't vent explosive hydrogen and oxygen gases into the room it's in. You can use a standard lead acid battery if it's located outside or in a well vented shelter. For the most part, bigger is better. Get one that will satisfy your backup needs power wise. More amp hours means more backup time. You need to make sure the charger is matched to the size of the battery. You want the battery to be recharged within a reasonable amount of time after it's used.

Exide Inva Tubular is a good option.
You can check some websites listed here:
http://indiahometips.com/inverter-batter…