Xantrex Technology 3000 manual Battery Sizing Example, Per Day Hours = a x B

Battery Types

Battery Sizing Example

This battery sizing example illustrates a typical calculation, assuming an opportunity to charge the batteries every three days.

			Daily watt-hours needed
	(A) Power	(B) Operating Time	for this appliance
Appliance	Consumption (Watts)	per Day (Hours)	(= A x B)
TV & VCR	200 W	2 hours	400 Wh
Microwave oven	1400 W	15 min = 1/4 hour	350 Wh
3 lamps, 60 W	180 W	4 hours	720 Wh
each
Coffee maker	600 W	15 min = 1/4 hour	150 Wh
Steam iron	700 W	6 min = 1/10 hour	70 Wh
	Total daily watt-hours of AC load		1690 Wh
	x Number of days between charges		3
	= Total watt-hours of AC load between charges		5070 Wh
	Battery Ah used between charges (divide by 10)		507 Ah
Recommended Battery Bank Size in Ah (multiply by 2)			1014 Ah

This example illustrates how quickly your battery needs can escalate. To reduce the required battery size, you can conserve energy by eliminating or reducing the use of some loads or by re-charging more frequently.

When sizing your battery, resist the temptation to skip the last step of this calculation (multiplying by 2). 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.

B–4 975-0128-01-01