Build an additional battery pack?

[alex-zero]

Hi,

have anyone expericene in building an addition battery pack für the mda-II?
With wlan i have only 90min to work on the device.

Maybe we can user an akku from camcorder or mobile phones? (Very small and powerfull)

The orginal mda-II akku has 1200mAh and the powerconnector loads the device with 5V max. 2A.

Any ideas?

AleX

[jens]

Hi!
What do you think of 5-6 AA/Mignon 2000 mAh rechargeable batteries combined with a low drop voltage regulator?
Maybe it fits in a old tape cassette cover?! (I don't have one available for testing.)
Jens

[alex-zero]

Great idea.. AA/Mignon in a old cassette cover.

I will test later on how much Ampere really is needed to load the pda and how much is need when the build in batterys are full. I think this is different.

My goal is to have enough power to use the wlan more than 5 hours if possible

regards
AleX

[sweeney]

O2 were talking about an add-on sleeve that includes a CF slot and extra battery. Available shortly apparently.

Steve

[sweeney]

Checking the O2 website see http://www.my-xda.com/backpack.html

[cruisin-thru]

I see battery extenders on ebay, just a small box with alkaline or rechargeable batteries inside, have you tried those, very cheap too.

[jens]

Backpack

Exclusively for Xda II, the backpack is a powerful expansion unit. The jacket provides a compact flash card slot, a 600mah additional battery and VGA/TV out, allowing you to connect your xda to a projector, monitor or even a television (PAL/NTSC).

This Compact Flash slot supports Wireless LAN, GPS, Bar Code readers as well as normal CF storage cards (including the IBM Microdrive®)

Alex wrote:

With wlan i have only 90min to work on the device. ...
The orginal mda-II akku has 1200mAh and the powerconnector loads the device with 5V max. 2A.

You need 5 hours of working batteries:
1200 mAh / 90 min => 800 mA / h
You need another 3 1/2 hour => 2800 mAh if current coming through the power connector is about worth the same as from internal battery.
A small plastic box with mignons seems to me more flexible. Do you really need 5 hour ?!
What's about a 6V sealed Lead-acid (right name :? ) battery with voltage regulator?
Put the battery in your backpack connected to your XDA by a wire and you can walk through your city. :wink:
Jens

[alex-zero]

tanks all for your answeres!!!

@sweeney
I have read about the backpack and it is very interessting with the CF-Slot but i heard a price of more than 200eu... thats to much for me. And the additional battery is with 600mah to small.

regards
AleX

[JoseF]

@alex
This one I have used with XDA II
The price is OK!.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3059925150&category=29846

[sweeney]

tanks all for your answeres!!!

@sweeney
I have read about the backpack and it is very interessting with the CF-Slot but i heard a price of more than 200eu... thats to much for me. And the additional battery is with 600mah to small.

regards
AleX

O2 were talking about a price of about £90 (about 130eu), then I was thinking in terms of a low power CF 802.11 card (say the socket unit (http://www.socketcom.com/product/WL6000-320.asp) which with a maximum requirement of 280mA in transmit mode and it's fancy power management drawing from the backpack's own power cell should be good for over 5 hours.

You could of course lug around a bunch of spair lithium cells or a battery pack and cable, kind of defeats the objective though.

Steve