Car Battery Amp Hours

These numbers are given by the factory of a car battery and it is just a simple linear formula.

Car battery amp hours. If a battery is said to have 20 amp hours of capacity it means that it can hypothetically discharge one amp of current for 20 hours 20 amps for one hour or any combination of amps and hours that equal 20 amp hours. Amp hour is the rating used to tell consumers how much amperage a battery can provide for exactly one hour. Amp hours are also heavily based on the relative capacity between two batteries which reduces accuracy levels in helping determine the exact time of use. Connect a basic resistor across the battery s terminals then monitor the discharge over time until the voltage decreases to 12 volts.

Larger suv truck and cars with larger electronic systems will have batteries around 60 111 ah. The smallest of car batteries will be 36 46 amp hour ah equivalency. To determine the ah rating of a 12 volt battery use a multi meter. If a battery s ampere hour is 100ah this tells you the battery can deliver 5 amps of power for 20 hours.

The power and longevity of a battery is noted by its amp hour ah rating. If a battery is rated as 100ah it will produce 100 amps for 1 hour. In small batteries such as those used in personal vaporizers or standard aa sized batteries the amp hour rating is usually given in milli amp hours or mah. The car battery capacity of 1 amp hour should be able to continuously deliver a current of 1 amp to a load for 1 hour 2 amps for half an hour and so on before being completely discharged.

Amp hours ah may be presented on your battery as 200ah 25 hr which means that the battery would provide a constant supply of usable current for 25 hours at a rate of 8 amps. The amp hours allow you to measure car battery amps through the practical lens of how long it will last between charges. A rule of thumb is that for a 1 hour discharge rate i e. A 24ah battery can deliver 1 amp for about 24 hrs or 2 amps for 12 hours etc lead acid 12 volt car batteries are fully discharged around 8 volts and if they are discharged below 6 volts they may not hold a charge reliably.

Charts that detail this effect for different discharge rate can be used for greater accuracy. For example if a battery is rated as say 8ah it will be able to provide 4 amps for 2 hours. Basically this denotes how long a battery will last if it isn t recharged. For example batteries rated in ampere hours ah also called amp hours are designed to deliver low currents for an extended period.

Larger car and smaller suv batteries are around 46 60 ah.