How to calculate battery back up time for a 400 AH battery
bank installed in telecom shelter for a load of 20 Amps and
time taken to fully charge this battery bank?

Answer Posted / pavan

Part -I:

400Ah Battery means the battery can supply a DC load of 400
Amps for a duration of 1 Hour until the battery gets fully
discharged. so if you are using the battery to supply the
above mentioned load of 20 Amps the battery can work for
400/20 = 20 Hours. provided the 20Amps is a Direct load
connected to the Battery. if you use the battery for a
inverter or UPS to suplly an AC load of 20 Amps. then the
duration is different.

Part - II:

For charging any battery we have to provide a voltage that
is slightly (5% - 10%) higher than the Battery terminal
voltage. The duration of charging can be known by the same
process as above. A 400Ah gets charged in 1 Hour provided
the charging source is capable of supplying 400 Amps to the
Battery. But normally the current of the charging source
will be limited to a lesser finite value. so if you can
know the maximum load the source can supply you can easily
calculate the duration required for the battery to get
fully charged.

Is This Answer Correct ?    27 Yes 5 No



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