Power Consumption; Turning Your Inverter On Or Off - Cobra CPI 880 Operating Instructions Manual

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 1 00 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 the 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.
50 watts x 2 hours
= 1 00 watt-hours
115 watts x 3 hours 300 watts x 15 minutes
=
345 watt-hours
=
75 watt-hours
4. Divide the watt-hours by 10 to determine how many power
supply's (12 volt) ampere-hours will be consumed.
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
tum
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
tum
the power inverter off:
1. On the left side panel,
switch the On/Off Switch
to off.
Ill\
NOTE The On/Off Switch turns the control circuit
\1fl
in the inverter on and· off. It does not disconnect
power from the inverter.
NOTE When the switch is in the off position, the
G
inverter draws no current from the battery. When it's in
the on position, but no power is being supplied to the
load, the inverter draws less than 500 milliamperes
from the battery. This is low current draw. It would
take more than a week to discharge a 1 00 ampere-
hour battery at this rate depending on the age of the
battery.
Nothing Comes Close to a Cobra®
~