If your Windows 2000 laptop can install 2 batteries, Windows 2000 may **NOT** run the **low** or **Critical** battery alarm,
as set in **Control Panel / Power Options / Alarms**.

The problem is caused by Windows 2000 improperly calculating the remaining time when 2 batteries are installed, and AC power is unplugged.

The formula for calculating remaining time is:

**RemainingTime\[h\] = RemainingCapacity\[mAh\] / PresentRate\[mA\]**

**NOTE:** Remaining time in hours is equal to Remaining Capacity in mili-ampere hours divided by the Present Rate of
battery power consumption in mili-amperes.

With 2 batteries installed, the formula should be:

**RemainingTime\[h\] = (RC1 + RC2) / (PR1 + PR2)**

Where:

**RC1** is the remaing capacity of the first battery.**RC2** is the remaining capacity of the second battery.**PR1** is the present rate of the first battery.**PR2** is the present rate of the second battery.

Unfortuneatly, Windows 2000 is using:

**RemainingTime\[h\] = (RC1 + RC2) / PR1**

This can result in a sudden loss of power.

I suggest that you either increase the power level percentage in an effort to compensate, or to be safe,
use one battery and have the **critical** alarm **Hibernate** your laptop so you can replace the battery.