But, for Lithium and Nimh, the discharge graph is so flat that the voltage stays reasonably constant throughout the discharge cycle, thus making a prediction of the capacity unreliable. These types of testers do an adequate job on alkaline batteries, as the discharge graph has enough slope to it that allows for a good prediction of the capacity. This voltage is compared to predetermined values from a discharge graph to turn on a certain number of LED's or bars in a graph display. There are commercially made battery testers that perform the test by placing a load on the battery for a few seconds and then a voltage is read. Without the load, you would think the battery was good. A battery might have a voltage reading 1.5 v., but when a load is placed on it the voltage may drop to below 0.8 volts in a few seconds. Are there other ways of testing a battery without discharging it to a non-usable state? You could check the voltage of a battery with a multimeter, but it is not a good test of the remaining capacity or condition of a battery as they do not place a significant load on the battery when taking a voltage reading.
We have worked with an engineer at Energizer and we both have concluded this statement is true. Unfortunately, the only reliable way to measure the remaining capacity of a battery is to run the above tests, but in the case of the Alkaline and Lithium batteries, that will discharge them to a non-usable state. The other two types of battery capacities are not significantly affected by the current load. Likewise, if a load of 500 ma is used a smaller milliamp capacity will result. If a test is completed with a load of 100 ma instead of 250 ma a higher milliamp capacity will result.
We have had cameras with alkaline batteries stop taking pictures during the coldest part of the winter and then return working again in early spring. The Lithium available capacity was not significantly affected by the 5° temperature and the NiMH was moderately affected.Īlkaline battery capacity tests will also vary according to the amount of current load used in the test. If this battery is returned to room temperature, its remaining capacity of 1453 mAh (2181 - 728 = 1453) will be available. Only 33% of its room temperature capacity is available at 5°. Battery TestedĪlkaline batteries are significantly affected by the 5° temperature. For comparison, we have completed this standard capacity test on Energizer AA Alkaline, Energizer AA Ultimate Lithium, and Tenergy AA Premium NiMH Rechargeable at room temperature and in a freezer at 5° Fahrenheit with a 245 ma load. However, the capacity is sometimes affected by temperature and the amount of the current load. In theory, this 3000 mAh battery would be able to produce 30 ma for 100 hours (3000/30 = 100) or 5 ma for 600 hours (3000/5 = 600), etc. For example, let's say it took 12 hours to discharge a battery to 0.8 volts, then the capacity would be 250 x 12 = 3000 mAh.
One standard test for AA batteries is to put a 250 ma load on the battery until the battery voltage is reduced to 0.8 volts. The test for capacity is to put a constant load on the battery until the voltage of the battery reaches a certain value. The capacity of AA batteries is usually stated in milliamp hours (mAh).
0 kommentar(er)
