Xantrex Technology PROwatt 1000 manual Estimating Battery Requirements, Battery Sizing Example

Battery Types and Sizes

Estimating Battery Requirements

To determine how much battery capacity you need:

1.Determine how many watts are consumed by each appliance that you will operate from the PROwatt 1000. You can normally find this on a label on the product. If only the current draw is given, multiply it by 115 to get the power consumption in watts.

2.Estimate how many hours each appliance will be operating each day.

3.Calculate the daily watt-hours needed for each appliance.

4.Add the total number of watt-hours needed for all the appliances and multiply it by the number of days between charges.

5.Divide the total watt-hours of AC load between charges by 10. This gives the battery Ah used between charges.

6.Double the total Ah used between charges to get the recommended battery size in Ah.

See the battery sizing example that follows.

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 for this
	(A) Power	(B) Operating	appliance
Appliance	Consumption	Time per Day	(= A x B)
TV & VCR	200 W	2 hours	400 Wh
Compact	800 W	15 min = 1/4 hour	200 Wh
microwave
3 lamps, 60 W each	180 W	4 hours	720 Wh
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		1540 Wh
	x Number of days between charges		3
= Total watt-hours of AC load between charges			4620 Wh
Battery Ah used between charges (divide by 10)			462 Ah
Recommended Battery Bank Size in Ah (multiply by 2)			924 Ah

B–4