Estimating Battery Requirements; Battery Sizing Example - Xantrex PRO XM 1000 Owner's Manual

Battery Types

Estimating Battery Requirements

Battery Sizing Example

Appliance
TV & VCR
Microwave oven
3 lamps, 60 W
each
Coffee maker
Steam iron
Recommended Battery Bank Size in Ah (multiply by 2)
B–4
To determine how much battery capacity you need:
1. Determine how many watts are consumed by each appliance that you
will operate from the XM Series Inverter. 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.
This battery sizing example illustrates a typical calculation, assuming an
opportunity to charge the batteries every three days.
(A) Power
Consumption (Watts)
200 W
1000 W
180 W
600 W
700 W
Total daily watt-hours of AC load
× Number of days between charges
= Total watt-hours of AC load between charges
Battery Ah used between charges (divide by 10)
(B) Operating Time
per Day (Hours)
2 hours
20 min. = 1/3 hour
4 hours
15 min. = 1/4 hour
6 min. = 1/10 hour
Daily watt-hours needed
for this appliance
(= A × B)
400 Wh
333 Wh
720 Wh
150 Wh
70 Wh
1673 Wh
3
5019 Wh
502 Ah
1004 Ah
975-0263-01-01