Estimating Battery Requirements

When sizing your battery, be conservative, and resist the temptation to skip the last (multiply by 2) step of this calculation. More capacity is better since you will have more reserve capacity, be better able to handle large loads and surge loads, and your battery won't be discharged as deeply. Battery life is directly dependent on how deeply the battery is discharged. The deeper the discharge, the shorter the battery life.

As your power requirements increase, you may need to use more than one battery to obtain sufficient capacity. Batteries can be connected in parallel or series to create higher capacity systems. It is not recommended to connect batteries from different manufacturers, different types, or that have different amp-hour ratings in parallel. Improper charging and decreased battery life will result. See “Cabling & Hook-up Configurations‚” on page 75 for more information on battery inter-connection schemes.

The following worksheet is provided as a guide for determining your battery needs. Be generous in estimating the time for which you will run each of the loads to ensure sufficient battery capacity.

Table 4: Battery Sizing Worksheet

Appliance

(A)

 

(B)

Daily watt-

 

 

 

 

hours needed

 

Power

 

Operating

for this

 

Consumption

 

Time per day

appliance

 

 

 

 

( = A x B )

 

 

 

 

 

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

W

 

hours

Wh

 

 

 

 

 

 

 

 

Total Daily Watt hours of AC load:

 

Wh

 

 

 

x Number of Days between charges:

 

 

 

 

= Total Watt hours of AC load between charges:

Wh

 

 

 

Battery Ah used between charges

 

Ah

(divide by 10 for 12V system, divide by 20 for 24V system)

 

 

 

 

 

Recommended Battery Bank Size in Ah (multiply by 2)

Ah

 

 

 

 

 

72

Prosine 2.5/3.0 Installation & Operation Guide