Using my Bluetooth-linked GPS unit with my iPAQ 2210 Pocket PC has the
serious downside that the 1000 mAH battery runs out after 3 hours or
so, nowhere near long enough for a day's walking/hiking.

I'm looking at a higher capacity battery (3300 mAH) but that has the
disadvantage that the 2210 would no longer fit its leather case. So an
alternative I'd like to explore is using conventional (alkaline or
NiMH) batteries. The lithium ion battery is apparently 3.7V. The DC
power unit plug that fits the cradle I use when at home reads 5.28V on
my meter. So a 6V set of 4 AA or C or D cells are candidates,
possibly with a diode in series. Has anyone tried this please? I'm
assuming there's protective circuitry to maintain the appropriate
voltage anyway. Presumably the lithium ion battery in place would get
charged simultaneously? Safely?

--
Terry, East Grinstead, UK

At 21 Apr 2008 13:36:59 +0100 Terry Pinnell wrote:

> I'm looking at a higher capacity battery (3300 mAH) but that has the
> disadvantage that the 2210 would no longer fit its leather case. So an
> alternative I'd like to explore is using conventional (alkaline or
> NiMH) batteries. The lithium ion battery is apparently 3.7V. The DC
> power unit plug that fits the cradle I use when at home reads 5.28V on
> my meter. So a 6V set of 4 AA or C or D cells are candidates,
> possibly with a diode in series. Has anyone tried this please?

I've done it- just a straght 4AA pack with no diode and connected it to
both an Audiovox Maestro (which used a 5.0V charger) and a Dell A im (used
a 5.4V charger.) 4 alkaline AAs caused the Maestro's charge indicator to
glow an undocumented red instead of the usual yellow (charging) or green
(done.) I assumed that was some kind to overload warning so I disconnected
it. The Axim didn't seem to mind it at all.

Rather than play with diodes, I simply substituted rechargeable batteries
(Ni-Cads and eventually Ni-MH.) Besides the advantage of reusability, they
output 1.25v each instead of 1.5, so a set of four is a nearly ideal (ideal
for the Maestro!) 5V. As a bonus, they're lighter than alkalines as well,
and have a steadier voltage curve. (Alkalines drop voltage steadily as
they are deeply discharge, so they drop below the needed 1.25v each before
fully drained- Ni-Cd/Ni-MH put out a steady 1.25v almost until fully
depleted.)


> I'm
> assuming there's protective circuitry to maintain the appropriate
> voltage anyway.

To a point yes- I blew a diode in my old Casio E-100 plugging in the wrong
charger (12V!) in error.

> Presumably the lithium ion battery in place would get
> charged simultaneously? Safely?


I've used my 4AA charger for years without incident. I built my first (the
Maestro and Axim used the same size DC plug), then bought a nicer looking
one off eBay. When I moved to my HTC Wizard (5.0v) I put a female USB plug
on my old home-built one to use the Wizard's charge/sync cable with it.

Terry Pinnell wrote:
> Using my Bluetooth-linked GPS unit with my iPAQ 2210 Pocket PC has the
> serious downside that the 1000 mAH battery runs out after 3 hours or
> so, nowhere near long enough for a day's walking/hiking.
>
> I'm looking at a higher capacity battery (3300 mAH) but that has the
> disadvantage that the 2210 would no longer fit its leather case. So an
> alternative I'd like to explore is using conventional (alkaline or
> NiMH) batteries. The lithium ion battery is apparently 3.7V. The DC
> power unit plug that fits the cradle I use when at home reads 5.28V on
> my meter. So a 6V set of 4 AA or C or D cells are candidates,
> possibly with a diode in series. Has anyone tried this please? I'm
> assuming there's protective circuitry to maintain the appropriate
> voltage anyway. Presumably the lithium ion battery in place would get
> charged simultaneously? Safely?
>

Surely a better option would be to stick with your existing battery and
case and use a plug in battery powered extender/charger, these can
usually be picked up on ebay cheaply: http://tinyurl.com/47b8ke



Mike

Mike <mikeloveschampagneandrugby@googlemail.com> wrote:

>Terry Pinnell wrote:
>> Using my Bluetooth-linked GPS unit with my iPAQ 2210 Pocket PC has the
>> serious downside that the 1000 mAH battery runs out after 3 hours or
>> so, nowhere near long enough for a day's walking/hiking.
>>
>> I'm looking at a higher capacity battery (3300 mAH) but that has the
>> disadvantage that the 2210 would no longer fit its leather case. So an
>> alternative I'd like to explore is using conventional (alkaline or
>> NiMH) batteries. The lithium ion battery is apparently 3.7V. The DC
>> power unit plug that fits the cradle I use when at home reads 5.28V on
>> my meter. So a 6V set of 4 AA or C or D cells are candidates,
>> possibly with a diode in series. Has anyone tried this please? I'm
>> assuming there's protective circuitry to maintain the appropriate
>> voltage anyway. Presumably the lithium ion battery in place would get
>> charged simultaneously? Safely?
>>
>
>Surely a better option would be to stick with your existing battery and
>case and use a plug in battery powered extender/charger, these can
>usually be picked up on ebay cheaply: http://tinyurl.com/47b8ke
>
>
>
>Mike

Thanks both.

Mike: Great idea, hadn't known of those. Duly bought.

--
Terry, East Grinstead, UK

Reading the comments below the article (lots and lots of them), there seem
to ne several ideas on the best way to do this;
http://www.hackaday.com/2005/01/20/h...-usb-battery/2

HTH,
Keith

"Terry Pinnell" <terrypinDELETE@THESEdial.pipex.com> wrote in message
news:th2p04t6ku8n7d73qffsmsvaapspkvplc4@4ax.com...
> Using my Bluetooth-linked GPS unit with my iPAQ 2210 Pocket PC has the
> serious downside that the 1000 mAH battery runs out after 3 hours or
> so, nowhere near long enough for a day's walking/hiking.
>
> I'm looking at a higher capacity battery (3300 mAH) but that has the
> disadvantage that the 2210 would no longer fit its leather case. So an
> alternative I'd like to explore is using conventional (alkaline or
> NiMH) batteries. The lithium ion battery is apparently 3.7V. The DC
> power unit plug that fits the cradle I use when at home reads 5.28V on
> my meter. So a 6V set of 4 AA or C or D cells are candidates,
> possibly with a diode in series. Has anyone tried this please? I'm
> assuming there's protective circuitry to maintain the appropriate
> voltage anyway. Presumably the lithium ion battery in place would get
> charged simultaneously? Safely?
>
> --
> Terry, East Grinstead, UK