Use this procedure to test the integrity of the battery in the NxE55 network engine. The life expectancy of the 12 VDC battery installed in the NxE55 is 3 to 5 years. The battery monitoring circuit of the NxE55 does not load test the battery. If the battery fails to maintain a proper voltage level during a power loss, the NxE55 may not be able to complete a normal shutdown and unarchived data could be lost. Therefore, periodically field test each battery or replace a battery that is well beyond its life expectancy, even if a battery fault condition does not exist. As a best practice, establish a regular maintenance schedule to check the batteries of all NxE55s currently in service.
Follow these steps to test the sealed 12 VDC battery used on NxE55s. (This procedure does not apply to the N40-class network engines, including the NCE25, NAE35, and NAE45.) To perform the test, you need to remove the battery from the network engine and assemble the parts listed here. Test leads are required to connect the 7.5 ohm resistor to the battery.
Parts required:
- 7.5 ohm, 25 watt resistor (Ohmite® part number D25K7R5) or equivalent
- Jumper wire test leads (22 or 24 gauge)
- DC voltmeter
- Stopwatch or other time source
Follow these steps:
- Verify the battery you want to test is fully charged.
- Connect the 7.5 ohm load across the battery.
- Wait 60 seconds, then record the voltage across the battery terminals (not across the load resistor).
- Wait another 60 seconds and again record the voltage across the battery terminals.
- Remove the load from the battery.
- Subtract the voltage reading taken in Step 4 from the voltage reading taken in Step 3. This is your difference reading.
- If the difference reading is less than or equal to 0.25 VDC, the battery is good. Reinstall the battery.
- If the difference reading is greater than 0.25 volts, the battery is no longer effective. Replace the battery.