Filter
Top Products
975-0697-01-01 53
Battery Information
This guide for use by qualified personnel only.
Estimating Battery Requirements
Calculating Battery Size
Step 1: Compute Amp-hours
For each appliance, compute the number of amp-hours that will be
used between charging cycles, as follows:
1. Obtain the wattage. If the wattage is marked on the nameplate
rating, use that. Otherwise, multiply the marked voltage and
amperage:
WATTS = VOLTS × AMPS.
2. Obtain the Watt-hours by multiplying that amount by the hours
the appliance will be used:
WATT-HOURS = WATTS × HOURS.
3. Obtain the amp-hours that the appliance requires by dividing
that amount by 20 (the factor for the Freedom SW 230V, which
is a 24-volt system):
BATTERY AMP-HOURS USED = AC WATT-HOURS÷10
For example, a 100 W light bulb that is used for 4 hours will use 400
watt-hours (Wh) and the inverter will consume approximately
40 Ah from a 12-volt battery.
4. Enter this information on the blank calculation worksheet
(page 56).
Step 2: Calculate Battery Size
5. Complete the rest of the worksheet; see Table 5, “Battery
Sizing Example” on page 54 for an example.
Size the batteries at approximately twice the estimated total amp-
hour usage. Doubling the expected amp-hour usage ensures that the
batteries will not be overly discharged and extends battery life.
Do not skip this doubling step. 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.
Troubleshooting If you find that the system shuts down when
appliances with large motors are started, the problem may be that
this motor is too much for the battery. Even though you calculated
the amp-hour requirements appropriately, the startup of a large
motor makes high demands on the battery. You may find that adding
more amp-hours (in the form of extra batteries or replacement with
a bigger battery) solves the problem.
Freedom SW 3K2K 230V InvChg Install Guide.book Page 53 Friday, June 20, 2014 9:11 AM