ECO Charger EC-90 Owner's Manual - page 6
OPERATING TIME
The operating time for the EC-90 is determined by the total battery current. The total
battery current is the sum of the current being drawn from the 12V unregulated output and
the regulated output. Since the EC-90 has two outputs, there are many possible output
load configurations. Establishing a run time for each possible device combination would be
difficult so we have provided the following formulas that you can use to estimate operating
time for your particular equipment combination.
To calculate the approximate operating time use the following formula:
T = (7.2Ah*0.6) / I
total
Where T is time in hours
I
total
is the total battery current (12V current plus current from regulator. See below)
Since the regulated output uses a high efficiency switch mode regulator, the actual current
being drawn from battery will be a fraction of the current being drawn from the regulator
output.
This can be approximated with the following formula:
I
battery
= I
reg
* (Current Factor)
Where I
b
is the battery current
I
r
is the regulator output current (power to your device)
Current Factor is the value from the table below.
MAINTENANCE AND STORAGE
During storage, it is advised to charge the battery once at least every six months. If the
battery has been stored for a long period in a discharged state, it may not be able to regain
it’s capacity even if it is recharged. If the battery is stored for a year or longer without being
charged, its service life may be shortened. Store the battery only after fully charging it.
5
Regulator Voltage
Current Factor
6V
0.55
7.5V
0.68
Table 2. Current Factors