Battery Capacity Measurement, Identify a Fake Battery, [Lithium-NiMH-NiCd][UID=d432]

RE: Battery Capacity Measurement, Identify a Fake Battery, [Lithium-NiMH-NiCd][UID=d432]

dougw — Wed, 09 Oct 2019 22:40:42 GMT

Nice work. I definitely have some batteries that do not perform as advertised. The 3rd party spare Lithium batteries I bought for my camera are the worst offenders. Their capacity is rated as higher than the original battery, but in reality they only last about 20% as long. In addition, they self discharge over the course of a few days - unlike the original which keeps its charge indefinitely.

RE: Battery Capacity Measurement, Identify a Fake Battery, [Lithium-NiMH-NiCd][UID=d432]

three-phase — Wed, 09 Oct 2019 21:09:24 GMT

Thanks for sharing this, I could do with a useful little project to get me started with Arduino.

Kind regards.

RE: Battery Capacity Measurement, Identify a Fake Battery, [Lithium-NiMH-NiCd][UID=d432]

neilk — Wed, 09 Oct 2019 13:43:59 GMT

A fascinating article and excellent video.

I was aware that not all brands of Lithium batteries deliver their claimed capacity, but this piece of kit to measure capacity is really useful.

I will add it to my list of projects to be done.

Thanks for sharing [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-f2a54c24-f8d2-417b-a671-05050bbaca7f/contentimage_5F00_1.png:16:16]

Neil

RE: Battery Capacity Measurement, Identify a Fake Battery, [Lithium-NiMH-NiCd][UID=d432]

dubbie — Wed, 09 Oct 2019 09:04:16 GMT

This is an interesting concept. I've not heard of fake batteries before. I know about batteries having different capacities and how difficult it is to obtain a realistic understanding of what they can do. I also know that the capacitor does depend on the current taken, so lower current drains get nearer to stated capacity values, whereas higher current drains lead to much lower apparent capacity as the battery chemistry cannot get the energy out fast enough. Plus, if you interrupt the current drain then the battery can recover - to some extent.

I used to do an experiment with my students to measure battery capacity, as an first exercise in using laboratory equipment. This was just a resistor in series with the battery and then measuring current and voltage over a two hour period. We started with carbon batteries which worked perfectly, provided the current flow was not interrupted, because if it was then the battery would last longer than the two hours. But then carbon batteries became difficult to obtain so we started to use alkaline and they were just too good! We could no longer obtain a complete discharge curve in the two hours available.

Batteries were a very interesting topic.

Dubbie