How To Measure Rechargeable Battery Capacity With Multimeter
To determine capacity, you need to actively discharge the battery, measure the current being drawn, and precisely time how long it takes for the battery to reach a safe cut-off
This post demonstrates the procedure to test the capacity of a battery. The test will determine and compare the battery's real capacity to its rated capacity. A load bank, voltmeters, and an amp meter will be utilized to discharge the battery at a specific current till a minimum voltage is achieved.
Convert to Amp-Hours (Ah): Multiply that average current by the total discharge time in hours. If your test ran for 4.5 hours, the math would be 0.9A x 4.5h = 4.05 Ah. Convert to Milliamp-Hours (mAh): Just multiply the Ah value by 1000. In this case, 4.05 Ah x 1000 = 4050 mAh. That final number is your estimated battery capacity.
Battery capacity testers typically function by discharging the battery under a controlled load and measuring how much energy it delivers until a cutoff voltage is reached. Here's a step-by-step breakdown: The battery is connected to the tester's terminals. Some testers are universal; others are specific to certain battery chemistries or voltages.
Yep, you absolutely can measure the capacity of non-rechargeable batteries like alkalines using the exact same discharge methods. The big thing to remember, though, is that it's a one-and-done, destructive test. Once you drain that AA battery to see what it's made of, it's completely spent.
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