What are Amp/Hours?

Batteries typically come with a number followed by Ah or mAh; but what does this mean? Well, the Ah stand for Amp-Hours & mAh is for milliAmp-Hours. Typically, vehicle batteries will come in Ah but some brands do use mAh as it makes them sound larger.

Ah is a measure of the current that can be supplied over time by the battery (i.e. roughly speaking a 10Ah battery can supply 1 Amp for 10 hours or 2 Amps for 5 Hours). This will give you a general idea of how much power you can draw from your battery and for how long.

Using these details, you can plan the type of battery you’ll need using the Amps of the items you’ll be using. Here is an example...

Say you have a fridge that draws 5 Amps continuously that you need to run off a battery for 9hrs before you need to recharge that battery. 5(Amps) X 9(hours) = 45 Ah required. Generally speaking, you do not want to take the battery below 50% level of charge, meaning you need a battery that has around 90Ah capacity.

Of course, different batteries have different discharge characteristics so should you need further help we recommend contacting your battery retailer or manufacturer.