Battery Ah Rating

This rating is acquired by adding a specific size load to a battery to make it completely dead in a 3 5 8 10 20 or 100 hour period.

Battery ah rating. In general terms the capacity of a cell battery is the amount of charge available expressed in ampere hours ah an ampere is the unit of measurement used for electrical current and is defined as a coulomb of charge passing through an electrical conductor in one second. What this means for a 100 ah rated battery is this. Such a rating cannot be extrapolated for very high currents or very long times with any accuracy. The amp hour also has sub units like the milliampere hour.

The standard rating is an amp rating taken for 20 hours. Draw from the battery for 20 hours and it will provide a total of 100 amp hours. For example batteries rated in ampere hours ah also called amp hours are designed to deliver low currents for an extended period. 5 x 20 100.

Discharged batteries lose voltage and increase in resistance. An amp hour battery rating is only an approximation of the battery s charge capacity and should be trusted only at the current level or time specified by the manufacturer. A c rating is simply a battery s capacity or ah amp hour rating when discharged over a specific period of time. To determine the ah rating of a 12 volt battery use a multi meter.

For instance at c 5 a battery might safely provide 26 8 amp hours. For large batteries the rating is abbreviated as ah. An amp hour ah is the amount of current a certain battery can supply for a certain period of time. In our previous post we focused on the definition of a battery s voltage and how it affects the battery s performance now we look deeper into another factor which greatly affects our batteries the ampere hour or amp hour rating.

This is a big effect in alkaline carbon zinc zinc air and lead acid batteries. To ensure that ratings are given in a realistic way lead acid batteries have a few parameters on how they get that ah rating. Battery application technology. The c rating tells you how many amp hours the battery can provide for a very specific period of time.

This is not the same thing as saying you use up what is available faster but you actually decrease the total overall capacity itself. Rate of discharge considerations. The battery s ah rating goes down the faster you use it. This is called the peukart effect.

Connect a basic resistor across the battery s terminals then monitor the discharge over time until the voltage decreases to 12 volts. Capacity and battery ratings review. An amp hour ah is a rating usually found on deep cycle batteries. C 2 88 ah 0 8 3 6 ah battery keep going step 3.

That translates to about 5 amps an hour.