Anyone here understand electronics? - Palmtop

This is a discussion on Anyone here understand electronics? - Palmtop ; I am attempting to shoehorn a bigger battery into my T3. The standard battery is 850 mah but it is possible to upgrade it to 1700 mah using an i705 battery. http://www.discount-battery.eu.com/p.../palm-i705.htm The two batteries are stacked, one on top ...

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Thread: Anyone here understand electronics?

  1. Anyone here understand electronics?

    I am attempting to shoehorn a bigger battery into my T3. The standard
    battery is 850 mah but it is possible to upgrade it to 1700 mah using an
    i705 battery.
    http://www.discount-battery.eu.com/p.../palm-i705.htm
    The two batteries are stacked, one on top of the other, in parallel and they
    will fit (with some surgery to the internal Palm plastic). The circuit board
    will not fit, so you need to find somewhere for it to lie on top of the Palm
    T3 motherboard and run two wires to the battery.
    I am following an idea originally on Brighthand forum:
    http://forum.brighthand.com/showthre...=236731&page=5
    So far:
    I have stacked the batteries together and they fit.
    I have checked the voltage of the parallel batteries and it is 3.7V (the
    same as the original Palm battery). I have used a multimeter and the
    polarity is correct.
    I have soldered the wires to the circuit board and when I connect the
    circuit board to the original battery, the Palm powers up, so the soldered
    battery circuit board works fine.
    When I connect the wires to the parallel batteries, the Palm does not work.
    In summary, the Palm works, the battery circuit board works, but when I
    connect it to two batteries in parallel with correct polarity and voltage
    (3.7V), it does not work.
    My electronics knowledge is patchy. Anyone got any thoughts?
    PS I have a spare T3, having cannibalised the bits to keep my other T3s
    running, so I can't do any serious damage.



  2. Re: Anyone here understand electronics?

    Mag wrote:
    > I am attempting to shoehorn a bigger battery into my T3. The standard
    > battery is 850 mah but it is possible to upgrade it to 1700 mah using an
    > i705 battery.
    > http://www.discount-battery.eu.com/p.../palm-i705.htm
    > The two batteries are stacked, one on top of the other, in parallel and they
    > will fit (with some surgery to the internal Palm plastic). The circuit board
    > will not fit, so you need to find somewhere for it to lie on top of the Palm
    > T3 motherboard and run two wires to the battery.
    > I am following an idea originally on Brighthand forum:
    > http://forum.brighthand.com/showthre...=236731&page=5
    > So far:
    > I have stacked the batteries together and they fit.
    > I have checked the voltage of the parallel batteries and it is 3.7V (the
    > same as the original Palm battery). I have used a multimeter and the
    > polarity is correct.
    > I have soldered the wires to the circuit board and when I connect the
    > circuit board to the original battery, the Palm powers up, so the soldered
    > battery circuit board works fine.
    > When I connect the wires to the parallel batteries, the Palm does not work.
    > In summary, the Palm works, the battery circuit board works, but when I
    > connect it to two batteries in parallel with correct polarity and voltage
    > (3.7V), it does not work.
    > My electronics knowledge is patchy. Anyone got any thoughts?
    > PS I have a spare T3, having cannibalised the bits to keep my other T3s
    > running, so I can't do any serious damage.
    >
    >

    Rule number one: lithium batteries can be dangerous...don't do it.
    There are different lithium technologies that have slightly different
    charge termination voltages. Don't get it wrong.
    There are lots of ways that protection boards work. It might be possible,
    maybe, that the board won't reset with a 3.7V battery. You may have
    to charge the battery with an approved lithium charger under carefully
    controlled conditions (take that lawyers) before the board will reset.
    You may or may not be able to do that with the charger in the T3.
    Your new batteries may be bad. High internal resistance is a typical
    failure/wearout mode. They'll measure ok open circuit, but still won't
    run the T3.

    --
    Return address is VALID!
    Bunch-O-Stuff Forsale Here:
    http://mike.liveline.de/sale.html

  3. Re: Anyone here understand electronics?

    > Rule number one: lithium batteries can be dangerous...don't do it.
    Mike - Thanks for the advice, but too late, i've already done it. Stupid me,
    I needed to charge the batteries. I put the whole lot in a box when I did it
    in case it went bang, but it charged fine.
    Mag



  4. Re: Anyone here understand electronics?


    "Mag" wrote in message
    news:goNQj.112845$5i5.69301@newsfe6-gui.ntli.net...
    >I am attempting to shoehorn a bigger battery into my T3. The standard battery is 850
    >mah but it is possible to upgrade it to 1700 mah using an i705 battery.
    > http://www.discount-battery.eu.com/p.../palm-i705.htm
    > The two batteries are stacked, one on top of the other, in parallel and they will
    > fit (with some surgery to the internal Palm plastic). The circuit board will not
    > fit, so you need to find somewhere for it to lie on top of the Palm T3 motherboard
    > and run two wires to the battery.
    > I am following an idea originally on Brighthand forum:
    > http://forum.brighthand.com/showthre...=236731&page=5
    > So far:
    > I have stacked the batteries together and they fit.
    > I have checked the voltage of the parallel batteries and it is 3.7V (the same as
    > the original Palm battery). I have used a multimeter and the polarity is correct.
    > I have soldered the wires to the circuit board and when I connect the circuit board
    > to the original battery, the Palm powers up, so the soldered battery circuit board
    > works fine.
    > When I connect the wires to the parallel batteries, the Palm does not work.
    > In summary, the Palm works, the battery circuit board works, but when I connect it
    > to two batteries in parallel with correct polarity and voltage (3.7V), it does not
    > work.
    > My electronics knowledge is patchy. Anyone got any thoughts?
    > PS I have a spare T3, having cannibalised the bits to keep my other T3s running, so
    > I can't do any serious damage.


    I'm not familiar with battery change in the T3, but lots of us have upgraded
    batteries in the Garmin iQue. In the iQue as you open the case, at some point (I
    don't recall now the exact point) the power to the motherboard disconnects. I believe
    it's when you undo the screws securing the motherboard. It's only when you reassemble
    everything back together the power is restored and the device hard-resets.

    It may be the same thing is happening in the T3. It may not work untill you get
    tighten back the screws of the motherboard. You cannot just test it with the
    motherboard loose from the base.

    Adam



  5. Re: Anyone here understand electronics?

    Adam
    It was a really simple thing. I needed to charge the replacement battery.
    Doh!



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