Juniper Systems Allegro DOS Manual - Manual (Page 45)

Hardware Features Page 2-27
3) Tap on OK.
Your Allegro is now set up fur use in vehicle power mode.
Battery Gauging Explained
The Allegro's intelligent battery gauging circuit helps you efficiently
maintain the batteries for applications. The percentage of remaining
charge in the batteries is indicated through the battery status LED
indicators. The gauging works for both NiMH rechargeable batteries
and alkaline batteries, although the mechanism is different, as outlined
in this section.
❖ Important Note: Battery gauging is provided as a tool to help you manage
your batteries. It does not affect the performance of the Allegro or the batteries
in any way. If the gauging circuitry is not properly synchronized with a NiMH
battery, it may show erroneous readings. Please read this section on battery
gauging so you understand the proper setup, functionality, and limitations of
battery gauging.
How Battery Gauging Works for the NiMH Rechargeable Battery
The Allegro employs a circuit that watches how much charge is added
to or removed from the rechargeable battery.
To illustrate how this circuit works, imagine the battery as a tank of
water. The battery capacity is like the size of the tank in gallons.
Watching charge is like watching how many gallons of water flow into
or out of the tank.
Gauging the battery is like gauging how full the tank is, without being
able to see into it. You must know the size of the tank and how full it
was to start with to determine the amount of water in the tank.
As water flows out of the tank, the percent full can be calculated by
subtracting how much water has flowed out of the tank from the
starting point and then dividing by the capacity of the tank. This is
exactly what the Allegro does, except it monitors milliamp-hours of
electric charge instead of gallons of water.
For the battery gauging to work correctly on the Allegro, the following
values must be known about the NiMH battery pack:
- Charge percent
- Capacity
Setting the battery charge percent and capacity are both described
earlier in this chapter in the Setting Battery Charge section.