4 Piece AAA High Capacity NiMH Rechargeable Batteries

Comments about Chicago Electric Power Systems 4 Piece AAA High Capacity NiMH Rechargeable Batteries:

I bought the AA and AAA and they perform the same or better then my Rayovac Platinum rechargeable at half the cost. I would recommend them to anyone that is looking for a good set of rechargeable batteries.

Comments about Chicago Electric Power Systems 4 Piece AAA High Capacity NiMH Rechargeable Batteries:

I ran an actual test on these AAA cells. Each cell was charged on a smart charger and then each was discharged through a 2.4 ohm resistor until the voltage was 0.9 V. The voltage of each was monitored with a data acquisition module connected to my computer. The data was loaded into Excel which calculated the milliamper-hours for each cell. I ran the test twice to see how much conditioning was needed to get them to full capacity. Here is the results with the first test for each cell separated from the second test with a /:. 874/888. 849/871, 901/920, 850/873. Notice that the capacity of each was almost as good on the first charge as it was on the second. This means that conditioning was not needed. Since memory effect is really the need for a cell to be periodically reconditioned by fully discharging and recharging, and since these did not need condtioning, then they will not show a memory effect. Quality manufactured cells have consistent capacity among samples; these are quite consistent and so I judge these very good. I have tested brand new cells where some samples were a fraction of the better ones and none meeting claimed capacity (milliamp-hours).

Comments about Chicago Electric Power Systems 4 Piece AAA High Capacity NiMH Rechargeable Batteries:

Since this is a technical review, I will refer to these using the proper "doctor" term as cells rather than batteries. A battery is more than one cell connected together, usually in series, to get the desired voltage. I charged all four cells in a smart charger and then each cell was discharged through a 2.4 ohm resistor until the cell voltage was 0.9 volt. The voltage was monitored with a data aquisition module connected to a computer. The test data was loaded into Excel which calculated the amp-hours of each. On first test the results were 874, 849, 901, 850 milliamp-hours. In the second test, they improved slightly: 888, 871 ,920, 873. The lowest capacity cell was within 5.3% of the best. That is very good and indicates good manufacturing and quality control. Since the first test was almost as good as the second, that means that these don't need to be conditioned before use which also means that they would not exhibit a memory effect. TIP: Charge a battery when the tool or light starts running down and never when it stops functioning. Running until dead will surely destroy the battery.

Comments about Chicago Electric Power Systems 4 Piece AAA High Capacity NiMH Rechargeable Batteries:

I would not recommend to charge them with a 15 minute charger, this casues the batteries to leak. However, they work better than popular radioshack or rayovac brand batteries in my side-by-side test.