: I usually do what Ford_6L_E350
says, but most of my flashlights require more than one battery making testing one battery impractical... However, the Amprobe which you guys discussed may be the thread which can unravel this puzzle. It led me to this $11 load tester (and there may be more):
which says this:
"A battery tester works by putting a load on a battery and measuring the voltage
at the battery terminals. The reason is that this voltage, measured with a good voltmeter that draws almost no current, changes little as the battery wears out. What does change is that the battery's internal resistance increases, which wastes energy, and the amount of chemicals available to generate current decreases. By putting a load on the battery, the meter can see whether the battery is still able to do its job."
Or check out this one:
"The ZTS Mini Multi-Battery Tester (Mini-MBT) provides a comprehensive means of testing more than 15 battery types. The Mini-MBT's microprocessor-based design makes battery testing simple - using a patented, high accuracy pulse load test. After a fully automatic test cycle, percentage of remaining battery capacity is indicated on the LED bar display. Battery types are clearly labeled next to appropriate contacts. There are no settings, and test results are easy to understand. Its small size makes it ideal for the gadget bag, toolbox, or home utility drawer. Negative test lead/probe conveniently stores in seam at side. Tests 1.5v alkaline (AA, AAA, C, D, N), 1.2v NiMH/NiCd, 3v photo lithium, and 9v alkaline."
Read about this one. I am not sure I can justify it over the mini:
"Yes, the tester has separate terminals for lithium AA and lithium AAA cells. The Energizer Ultimate Lithiums can be expected to have somewhat longer useful life than "ordinary" lithium cells, but the tester will accurately show their condition. This is simply the best tester out there, and if you're like me, you'll quickly realize what a good investment it is."
My bag of batteries may have to wait until I save up enough for that baby...
Thanks! (back to packing wheel bearings...)