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Thread: Battery Size In A Jump Starter Pack

  1. #1
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    Battery Size In A Jump Starter Pack

    Can any one tell me if there is a way to know how many true amp hours are in a portable jump starter.

    I know this will vary depending on its size.

    I have a son coming back from USA and the unit that I want says 2000A peak 20000mAh

    Now to me this is gobberlygook. To travel with it on a plane a lithium battery has to be under 100 watt.

    How do I or airport authorities calculate this?

    This is the unit Robot or human?
    Dave.

    I was asked " Is it ignorance or apathy?" I replied "I don't know and I don't care."



    1996 TDI ES. 2003 TD5 HSE

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    Quote Originally Posted by d2dave View Post
    Can any one tell me if there is a way to know how many true amp hours are in a portable jump starter.

    I know this will vary depending on its size.

    I have a son coming back from USA and the unit that I want says 2000A peak 20000mAh

    Now to me this is gobberlygook. To travel with it on a plane a lithium battery has to be under 100 watt.

    How do I or airport authorities calculate this?

    This is the unit Robot or human?
    20000ma = 20A
    20A x 12v = 240watts
    Damien
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    Quote Originally Posted by Vern View Post
    20000ma = 20A
    20A x 12v = 240watts
    Thanks Vern. I understand ohms law. What I do have trouble with is that such a small device could have a 20 ah battery.

    This being the case I could run my 40 litre Engel for about 13 hours off this.
    Dave.

    I was asked " Is it ignorance or apathy?" I replied "I don't know and I don't care."



    1996 TDI ES. 2003 TD5 HSE

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    BradC is offline Super Moderator
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    They don't. They have a total of 20AH @ a nominal 3.7V. That gets divided by 4 to get a nominal 14.8v (peak of 16.8 but it'll put a float on the car battery sharpish). So realistically 5AH, but then that's also Chinese Amp Hours, or 5AH PMPO.

    My power bank here is 26800mAH and the label says 99.16WH.

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    Why import one when they are cheap as chips here - mine off ebay was a little less than $100.
    REMLR 243

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    BradC is offline Super Moderator
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    Quote Originally Posted by d2dave View Post
    Can any one tell me if there is a way to know how many true amp hours are in a portable jump starter.

    How do I or airport authorities calculate this?

    This is the unit Robot or human?
    Right there on the specifications page: Capacity: 20000mAh (73.2Wh)
    So they've used a nominal voltage of 3.66V

    The way to know how many "true" amp hours are in the device is to do a couple of calculated discharge tests. I have a specific rig built to do that with a controllable load, a couple of GPIB volt meters and a calibrated shunt. But that's probably a bit more than you need.

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    Quote Originally Posted by 101RRS View Post
    Why import one when they are cheap as chips here - mine off ebay was a little less than $100.
    From my research it appears to be a really good brand and freight is free, so no much over a $100
    Dave.

    I was asked " Is it ignorance or apathy?" I replied "I don't know and I don't care."



    1996 TDI ES. 2003 TD5 HSE

  8. #8
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    Quote Originally Posted by d2dave View Post
    From my research it appears to be a really good brand and freight is free, so no much over a $100
    Make he doh me checks he can carry in checked in luggage Battery Size In A Jump Starter Pack

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