I just bought a NiMH battery in PP3 (9V battery) form-factor. It is GP ReCyko 20R8H. The brand was previously unknown to me. The label said that its capacity is 200mAh with nominal voltage 8.4V. This is probably a 7 cell battery, as NiMH cell nominal voltage is 1.2V each. This is supposedly a LSD (low self-discharge) battery. The box says it “retains up to 80% power” after 1 year. Interesting that it says “power” instead of charge. The box also says it can be recharged 1000 times. I downloaded the datasheet PDF from elpro.
Anyway, the price (Rp95k) was rather expensive for a single battery, so I wanted to make sure I didn’t receive a fake product.
After I received it I discharged it to 6.3V, let it rest, and then charged it using my bench power supply. The setting I used was 10.5V with 25mA current limit. I let it charge for 14 hours and it reached 10.15V. As far as I can tell it didn’t get warm. I let it rest for 1 hour before I tested the capacity. At that point the voltage had dropped to 9.84V.
I tested it using Zhiyu ZB2L3 with a 100Ω 5W power resistor. This tester can only do constant resistance test. Before testing I had calibrated the ZB2L3 using this instruction. I set the cut-off voltage to 6.3V. The test result: measured capacity was 206mAh.
Conclusion: I probably received a non-fake product 👍
I don’t have a battery charger for this. Maybe I’ll build a simple one 🤔