Samlexpower SSW-350-12A Manuel Du Propriétaire page 11

DETERMINING BATTERY SIZE
The power inverter will require DEEP CYCLE lead acid batteries of appropriate capacity.
The automotive SLI (Starting/lighting/Ignition) battery is not designed for repeated deep discharge. The SLI
battery may not supply enough energy and its service life may be reduced.
To determine the minimum battery size that you will need to operate appliances, follow these steps:
1. Determine the AC wattage of each appliance and / or tool you will need to simultaneously operate from
the inverter. To do this, read the labels on the equipment to be operated. Usually, power consumption is
shown in Watts. If it is shown in Amps, multiply by 115 to determine the AC wattage.
2. for each appliance, estimate the number of hours the appliance will be in use between battery
recharges.
3. for each appliance, determine the Watt-Hours of energy required by multiplying the AC wattage by the
number of hours of use.
4. Add the Watt-Hours of energy for each appliance to get the total Watt-Hours of energy for all
appliances to be used.
5. Divide the total Watt-Hours of energy on the AC side by 10 to get the total Ampere-Hour of energy on
the 12 VDC side to support the operation of the appliances.
6. The Ampere-Hour (AH) capacity of the battery should be 2 times the total Ampere-Hour energy required
on the 12 VDC side to support the operation of the devices (as calculated at step 5 above). Two times
factor is necessary because batteries are normally not discharged below 50% capacity.
To get an estimate of the current (in Amps) that the battery is delivering, divide the load's AC consumption
power (in Watts) by (10).
Keep in mind that most appliances are not operating for long periods of time. for example, a typical home-
use coffee maker draws 500 Watts during its brew time of 5 minutes, but it maintains the temperature of the
pot at about 100 Watts. Typical use of a microwave is only for a few minutes, sometimes at low power. Some
exceptions to brief operating times are TVs, computers etc.
In most instances, the inverter can be left connected to the battery when not in use, make sure power switch is
in the OFF position.
battery performance drops in low temperature environment. Higher capacity batteries should be installed if
the environmental temperature is below 20 C.
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OPERATING TIPS
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