These are small Sealed Lead Acid batteries that are generally used for semi-portable appliances that need more power or a fair bit of power (more than can be provided by D, C or AA cells) for a longish time. They are typically used for people who go caving, or for lighting for an overnight camping trip where you are travelling on foot. They are not ridiculously heavy or bulky. They are good to drive a lantern on a tinny for that night fishing expedition. Being sealed, you cannot fear that the battery acid (which is actually a GEL) will spill. The amp-hour rating tells you how long the battery will last before it goes flat. For example, a 7.2Ah battery will give 7.2 amps for one hour or 3.6 amps for 2 hours or 1.8 amps for 4 hours, etc. Generally an adequate amount of current for a lantern. They are ideally charged by solar panels. Also often found in alarm systems, NBN installations, and other critical systems with backup batteries.Features Leak proof construction Usable and rechargeable in any position Capable of high discharge rates Deep discharge recovery Wide range of operating temperatures Long service lifeSpecifications Packaged Volume : 1.29l Packaged Weight : 2.18kg Packaged Length : 15.8cm Packaged Width : 7.3cm Packaged Height : 11.2cm Length : 151mm Height : 95mm Depth : 65mm Weight : 2.2kg DC Voltage : 12V Battery usage : Rechargeable Battery Chemical Composition : Sealed Lead Acid (SLA) Battery Peak Current : 108A Amp Hour Rating : 7.2Ah 20 Hour Capacity : 7.2Ah 10 Hour Capacity : 6.48Ah 5 Hour Capacity : 5.76Ah 1 Hour Capacity : 4.32Ah Internal Resistance : 25Ω Connection Type : Spade Terminals Type of battery : SLA Block Recharging Voltage : 14.4V, 15V Standard Recharge Current : 720mA Recharging Time : 12hr