Ramble: 1.5-volt lithium polymer AA battery? What sorcery is this?

Been a while since I’ve posted anything on here, but I decided to share my thoughts on a peculiar AA battery.

This AA battery is the Kentli lithium-polymer AA cell. It has a built-in 1.5 volt regulator that converts the typical 3.7 volts down to 1.5 volts (open-circuit at least). I bought a 4-pack of these cells from AliExpress back in October, but have yet to receive them. Even though I haven’t gotten them, there is some things that I’ve taken note of.

Current/voltage output

A graph promoting the battery discharge curve of the Kentli cell is shown below, taken from a sales page on AliExpress (rehosted on this blog to prevent image bandwidth-hogging):

705255222_102The interesting thing I found out was the green dashed line. This is supposed to represent the output voltage when used in a wireless microphone. However, the graph itself provides no meaningful data because no current loads are specified at all. In an attempt to get some sort of information from the graph, a Google search for a spec sheet for a typical microphone gives a discharge current of 125 mA. But a 0.3 volt drop at 125 mA? I dunno, this doesn’t seem right.

Safety

From a safety point of view, I’m not sure about how much temperature would rise in the cell from high current draw and whether overheating could occur in use, and if any typical Li-Ion protection circuitry is used (voltage and discharge protection). Given how this is made by some relatively unknown Chinese company, who knows.

I’m not saying anything definite until I see these cells and have a chance to get my paws on them for testing and disassembly. Until then, we’ll just have to wait.

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6 thoughts on “Ramble: 1.5-volt lithium polymer AA battery? What sorcery is this?

  1. Did you receive these batteries, finally? If so, have you had a chance to check them out?
    We’d be very interested to know this information.

  2. I have bought several kentli aaa, aa, 9 volt.
    Great batteries, I was most impressed by their low leak (when not in use).
    Lasts a long time than my reg nimh (more than twice the time)

  3. From what I can see, in the graph the dashed lines are the “Electronic cut-off voltage”. Meaning that the wireless microphone will no longer power on when the battery voltage reaches the line (about 1.22 volts). In the alkaline battery this would be at about 45% of the capacity and at about 60% for the NiMH.

  4. Pingback: Teardown of Kentli PH5 1.5 V Li-Ion AA battery | Rip It Apart – Jason's electronics blog-thingy

  5. Pingback: Teardown of Kentli PH5 1.5 V Li-Ion AA battery -Use Arduino for Projects

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