Understanding Battery Testers

Battery testers that provide an amp hour reading may seem convenient, but misinterpreted readings could leave fire systems and other critical security/life safety equipment with insufficient backup power.


ALL Battery testers test conductance, which is measured in Mhos. Conductance is critical to storing a charge, thus to battery life. Chemical makeup, substandard lead, amount of lead, and corrosion affect conductance/Mhos. Not all batteries are alike. However, once any battery’s conductance is at 71% of its original conductance when new, the battery should be replaced and recycled. At 70%, a battery is unable to store a charge.

Most battery testers display an Amp hour reading based on an automatic calculation after the conductance/Mhos test. The problem with an Amp hour display is the false confidence it can provide. Consider a 7Ah battery being tested displays 5Ah. The battery is at 71% conductance so it is ready to be recycled, but the amp hour reading may lead the installer to believe the battery can provide 5Ah of backup power.

An ELK-BLT Battery LifeTester™ displays Mhos, not Amp hour, as again, not all batteries are alike. A display of Mhos is not susceptible to differences or changes in battery makeup – it simply displays the Mhos/conductance of that particular battery.

Installers can monitor the health of the battery, from initial installation and throughout the life of the battery, by noting the Mhos/conductance reading of each test on the ELK-BLT test data label. Since installations vary by control system, available power, environmental conditions and more, there is no set lifetime for a battery.

An ELK-BLT prevents disposal of good batteries and identifies batteries with poor conductance without trusting an expected lifetime. Installers of fire and security systems checking batteries during visits will know when to change the battery.

The included padded carrying case & self-adhesive test labels with each ELK-BLT make it an even better value!

The ELK-BLT carries ELK’s Lifetime Limited Warranty.




Battery LifeTester™



Test Data Labels for ELK-BLT

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