Tools & calculators

Battery charge time calculator

This calculator is designed to calculate the maximum battery charge time for any given chargable batter. The calculator will calculate the time after you enter the battery rating capacity, charge rate and the efficiency of the charging system, including the battery. The normally accepted standard for efficiency loss is 20%-30%.

Sample values for a car is 60ah and 0.8A for with the Optimate 4 charger
Sample values for a Motorbike is 20ah and 0.6A for with the Optimate 3+ charger


Battery charge time calculator

 

This is the time taken to recharge an absolutely flat battery
Battery capacity Amp hour (Ah)
Charge rate Amp (A)
Between and hours.

Calculation based on a 70-80% charging Inefficiency

     

Battery size calculator

To calculate approximately how big a battery and inverter you require for your power backup needs in Amp-hours (Ah), enter the power of each appliance and the average length of loadshedding time. The first couple of lines are given as an example; just click in the boxes to replace the values with an estimate of your own power consumption.

To calculate approximately how big a battery and inverter you require for your power backup needs. in Amp-hours (Ah), enter the power of each appliance and the average
length of time loadshedding time. The first couple of lines are given as an example; just click in the boxes to replace the values with
an estimate of your own power consumption.

Battery size needed calculator


Appliance Watts   Amp hour
Hours downtime required
We’re also catering for a 90% effecency in inverter, baterry and charger
 
You need a
Amp Hour battery