La Crosse Technology BC-500 Instruction Manual page 15

When the rechargeable batteries are fully charged, the capacity (Ah)
(Figure 12) and the voltage (V) (Figure 13) will be shown alternately with
"FULLTEST" displayed on the LCD.
(Figure 12)
(Figure 13)
Note: When any one of the batteries is in the test mode, do not change
the other battery(s). To test additional battery(s), you must remove and
reinstall the testing batteries and then reset the mode.
The capacity
Test mode
The voltage
Test mode
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