Xantrex Technology XS400 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 XS400. You can normally find the watt rating labelled 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
	(A) Power	(B) Operating	needed for this
	Consumption	Time per Day	appliance
Appliance	(Watts)	(Hours)	(= A x B)
TV	100 W	4 hours	400 Wh
VCR	100 W	4 hours	400 Wh
3 lamps, 60 W each	180 W	4 hours	720 Wh
Audio system	60 W	4 hours	240 Wh
DVD player	100 W	2 hours	200 Wh
Other loads	100 W	3 hours	300 Wh
Total daily watt-hours of AC load			2260 Wh
x Number of days between charges			2
= Total watt-hours of AC load between charges			4520 Wh
Battery Ah used between charges (divide by 10)			452 Ah
Recommended Battery Bank Size in Ah (multiply by 2)			904 Ah

B–4 975-0054-01-01