The maximum amount of charge for a fully charged battery to release a stored amount of electricity (ampere-hours/Ah) with a specified current (ampere/A) over a specified time (hours/h).
How much does a high discharge current affect battery capacity?
With a higher discharge current, of say 40A, the capacity might fall to 400Ah. In other words, by increasing the discharge current by a factor of about 7, the overall capacity of the battery has fallen by 33%. It is very important to look at the capacity of the battery in Ah and the discharge current in A.
What is battery capacity?
Battery capacity shows how much energy the battery can nominally deliver from fully charged, under a certain set of discharge conditions. The most relevant conditions are discharge current and operating temperature. Varying either of these can really impact performance, changing the capacity of the battery. See the example below.
The discharge current can then be worked out from the C-rate and the Nominal Capacity. For example if a battery has a C1 capacity of 400Ah, this means that when the battery is discharged in 1 hour, it has a capacity of 400Ah. The discharge current would have to be 400A to discharge the battery in an hour.
What is the rated capacity of a battery?
Under well defined conditions this is often referred to as the Rated Capacity as the battery capacity is likely to be different under different temperature, discharge rates and prior use. An alternative unit of electrical charge. Product of the current strength (measured in amperes) and the duration (in hours) of the current.
How long can a battery be discharged?
Maximum 30-sec Discharge Pulse Current –The maximum current at which the battery can be discharged for pulses of up to 30 seconds. This limit is usually defined by the battery manufacturer in order to prevent excessive discharge rates that would damage the battery or reduce its capacity.
How do you calculate battery capacity?
Capacity is calculated by multiplying the discharge current (in Amperes) by the discharge time (in hours) and decreases with increasing discharge current. For secondary batteries, nominal capacity is usually given as capacity for a specific discharge rate, typically for stationary batteries a 10-hour or a 20-hour rate.