Now that electronic cigarettes have reached the point where you can buy a complete disposable one in pound shops (dollar stores) it's interesting to note that despite being "disposable" they may actually have a rechargeable lithium cell in them due to the sheer mass production of rechargeable cells making them available cheaply in a huge range of sizes.
I decided to put this to the test and removed a cell from an e-cig. They don't have any built in protection circuit against overcharging and discharging (that bit's normally built into the e-cig control circuit) so I used the protection board out of another cell to build a module that allowed me to charge and test the cell. I ran a cautious charge cycle, monitoring the cell for swelling, temperature increase or venting (I put it in a non flammable container!) and it took a full charge in about an hour at 100mA. I then plugged a load onto the protection circuits output and it supplied about 100mA for an hour before the protection circuit kicked in. I then repeated this for several charge-discharge cycles and the cell does seem to be a fully rechargeable cell.
Obviously I can't guarantee this between different brands, but so far the EZI-cigs do seem to contain a 75400 (7.5mm diameter by 40mm long) 90mAh rechargeable lithium cell.

11 thoughts on “Unexpected source of a rechargeable lithium cell.”
  1. Avataaar/Circle Created with python_avatars Twelve Guage says:

    i got a large box of these of like 5 different sizes that a store had discontinued and was throwing away complete with chargers, and i use them for everything!!!

  2. Avataaar/Circle Created with python_avatars phorzer32 says:

    Nice

  3. Avataaar/Circle Created with python_avatars Mikhail Romanov says:

    19mAh!? Not 190? That is absolutely microscopic.

  4. Avataaar/Circle Created with python_avatars John F says:

    What a big puff! The ciggie that is!

  5. Avataaar/Circle Created with python_avatars KoolBreeze420 says:

    I've never seen these for a dollar anywhere near me cool maybe soon they are rechargeable even ones they say or not I've been selling them for years.

  6. Avataaar/Circle Created with python_avatars Stanley Scalf says:

    A standard 18650 Li-ion Batt has a capacity of 1500 to 3500 mAh with an output between 15A to 30A (the higher the rated mAh the lower the output rating. Obviously) while the little 75400 cells only have a capacity of around 150 mA to 300 mAh. Other than running little pen gadgets and stuff they aren't good for much I can think of even strung together. Considering the cheapest you can get a 75400 is by harvesting them out of $1 E-cigs and 18650 batteries easily found online for less than $10 the cost to capacity is still better for the 18650s or even bigger cells like the 26650s. Still a neat little discovery.
    Edit: sorry I didn't see this video is over 5 years old until after I wrote all that nonsense. Cheers!

  7. Avataaar/Circle Created with python_avatars joe jane says:

    Great video. The battery is labeled as 3axis say a 18650 is 18mm x 65mm x 0mm the zero is if the battery was not round L x W x H.
    Say a rectangle battery 10 x 50 x 20. A 400mm long battery is 40cm or .4 meter. It got me for a while too. But your videos are top notch.

  8. Avataaar/Circle Created with python_avatars Trevor van Bremen says:

    LOL @ '400mm long'… That's a LONG cell ya got there Clive!

  9. Avataaar/Circle Created with python_avatars Phil Chadwick says:

    Half the time, there's a 50% chance that 95% of the statistics I read are made up, including this one.

  10. Avataaar/Circle Created with python_avatars Domino52o says:

    Kinda surprises me nobody said anything about Clive unintentionally saying it was 7.5mm In diameter x 400mm in length. Wouldnt that be nearly half a meter long?

  11. Avataaar/Circle Created with python_avatars David Price says:

    400 mm long ????== 15.7 inches WTF? 40 mm I think!

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