Operation
3–2
About Charging
This section provides information about
• calculating the charging time
• effect of battery temperature on charging
• indicator light activity during the charging process
• using a generator to run Truecharge+

Charging Time

Formula Charging time will depend on the capacity of your battery and on how
deeply it is discharged.The following equation calculates an approximate
charging time:
where:
Example A Group 27 size battery rated at 82 amp-hours is 40% discharged, that is,
it has a DOD = 40. Charging time with a Truecharge 20+ unit is
calculated as follows:
Charging time = CAP x DOD
CC x 80%
Charging Time: Battery recharge time in hours
CAP: Battery capacity in amp-hours
DOD: Battery depth of discharge in per cent. A fully
discharged battery has 100% DOD
CC: Charge current, the rated current output of the
charger in amperes
80%: Typical charging efficiency for lead-acid batteries
Charging time = 82 Ah x 40% = 2 hours
20 A x 80%