Batteries for backup power storage can range from tiny AAA electronics batteries weighing less than an ounce to large glass matrix battery banks weighing hundreds of pounds.

This article focuses on backup power for RV, home, commercial or jobsite use. 

If the need for backup power is only for a short duration, batteries storage alone can do the job.  For large loads or extended backup power time, power generation is used in conjunction with battery storage. 

A common size of battery used to compare backup power systems for home, commercial or jobsite use is a 125 amp-hour, 12 volt, deep cycle glass matrix battery. Amp-hour is short for ampere-hour and is abreviated in a variety of ways including, Ah, ahr, Ahr.