Power Consumption •
For each piece of equipment you will be operating from the
inverter, you must determine the battery’s reserve capacity
(how long the battery can deliver a specific amount of
current – in automotive batteries, usually 25 amperes) or
ampere-hour capacity (a measure of how many amperes
a battery can deliver for a specified length of time).
Example – Reserve capacity: a battery with a reserve
capacity of 180 minutes can deliver 25 amperes for
180 minutes before it is completely discharged.
Example – Ampere-hour capacity: a battery with
an ampere-hour capacity of 100 ampere-hours can
deliver 5 amperes for 20 hours before it is completely
discharged.
To Determine the Battery Ampere-Hour
Capacity You Require:
1. Determine how many watts each piece of equipment
consumes. This can normally be found on the product
label. If only the current draw is given, multiply the
current draw by 115 to get the watt consumption.
2. Estimate the time (in hours) that each piece of equipment
will be running between battery charging cycles.
3. Calculate th total watt-hours of energy consumption
(power x operating time) using the average power
consumption and the total estimated running time
(in hours). Power x Operating Time = Watt-Hours.
4. Divide the watt-hours by ten (10) to determine how many
power supply’s (12 volt) ampere-hours will be consumed.
11
Nothing comes close to a Cobra™
10 English
Turning Your Inverter On or Off •
Be sure to have your power inverter properly installed before
attempting to turn the unit On (see “Installation” page 5).
To Turn the Power Inverter On:
1. If a DC power supply is being used as the power
source, switch it On.
2. On the left side panel, switch the On/Off Switch to On.
The inverter is now ready to deliver AC power to your loads.
If several loads are to be operated by the inverter, turn them
On separately, after the inverter has been turned On. This
will ensure that the inverter does not have to deliver the
starting currents required for all the loads at once.
To Turn the Power Inverter Off:
1. On the left side panel, switch the On/Off Switch to Off.
NOTE The On/Off Switch turns the control circuit
in the inverter On and Off. It does notdisconnect
power from the inverter.
Continued…
Power Consumption
Installation
On/Off Switch to On
On/Off Switch to Off
Power On & Off
Operation
Laptop
100 Watts x 2 hours
= 200 Watt-Hours
TV/VCR (up to 25")
115 Watts x 3 hours
= 345 Watt-Hours
Blender
300 Watts x 15 min
= 75 Watt-Hours