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-   -   Exteral battery use (https://talk.maemo.org/showthread.php?t=7080)

bizshop 2007-06-29 17:56

External battery use
 
BP-5L batteries are dirt cheap (~2.00 on eBay). I've gotten three, and expnse/combined weight is much less than most other options(Solio, etc) to keep me going for up to 28 hours on my n800.

Only drawback is having to open case to swap. Any ideas on some kind of adapter/dongle/jury rig to hook up batteries externally?

Karel Jansens 2007-06-30 14:16

Re: External battery use
 
Quote:

Originally Posted by bizshop (Post 54928)
BP-5L batteries are dirt cheap (~2.00 on eBay). I've gotten three, and expnse/combined weight is much less than most other options(Solio, etc) to keep me going for up to 28 hours on my n800.

Only drawback is having to open case to swap. Any ideas on some kind of adapter/dongle/jury rig to hook up batteries externally?

The biggest problem is that LiIon batteries start ageing (and thus losing capacity) from the moment they're made. If you have three batteries, each with an estimated lifespan of two years, your three batteries will be good for two years.

That's why I don't buy spare LiIons anymore, but go for external batteries that mimick an AC charger.

luketoh 2007-06-30 14:26

Re: Exteral battery use
 
Hi Karel,

Those external devices that you use to mimic ac adapter...what do you think they use in it?

Karel Jansens 2007-07-01 00:04

Re: Exteral battery use
 
Quote:

Originally Posted by luketoh (Post 55144)
Hi Karel,

Those external devices that you use to mimic ac adapter...what do you think they use in it?

Mine uses 4 AA batteries... :p

luketoh 2007-07-01 04:40

Re: Exteral battery use
 
Hi Karel,

I see! but batteries are expensive aren't they? i thought it would be more cost effective to use a lithium polymer ext battery pack.

bizshop 2007-07-01 07:41

Re: Exteral battery use
 
As I mentioned, I can get BP-5L batteries for less than a couple bucks apiece - so aging is not an issue really - buying new ones every year would still be a lot cheaper than AA batteries + external power unit,etc. Not to mention that some of these require different power convertors/tips - I already carry the charger to the n800 and don't want another.

I'm hoping to talk to some modder types who can figure out an external battery pack that the BP-5L will fit in and power the n800.

Karel Jansens 2007-07-01 14:45

Re: Exteral battery use
 
Quote:

Originally Posted by luketoh (Post 55292)
Hi Karel,

I see! but batteries are expensive aren't they? i thought it would be more cost effective to use a lithium polymer ext battery pack.

I use rechargeable (2500 mAh) AAs.

And I happen to have an external LiPoly pack. It's just that it puts out either 16 or 19 volts (it's for my old tablet, which has a busted battery) and I haven't gone around (yet) figuring out how to best drop the voltage to 5 volts. A pack like that could power my N800 for days on end...

Karel Jansens 2007-07-01 14:49

Re: Exteral battery use
 
Quote:

Originally Posted by bizshop (Post 55317)
As I mentioned, I can get BP-5L batteries for less than a couple bucks apiece - so aging is not an issue really - buying new ones every year would still be a lot cheaper than AA batteries + external power unit,etc. Not to mention that some of these require different power convertors/tips - I already carry the charger to the n800 and don't want another.

I'm hoping to talk to some modder types who can figure out an external battery pack that the BP-5L will fit in and power the n800.

In that case it might be easier to look into a solution that involves a smallish capacitator that will keep the N800 powered for the short period it takes to switch batteries. It could possibly even be built into the N800 itself. Fujitsu's Stylistic tablets (used to?) have this: You could take out the depleted battery and drop in a new one without having to reboot; just standby would do the trick.

luketoh 2007-07-02 01:44

Re: Exteral battery use
 
Hi Karel,

I think a simple regulator circuit would do the trick.


Luke

distguitar 2007-07-02 02:58

Re: Exteral battery use
 
BP-5L are showing as 770's batteries, n800 pulls up Exim hi cap 1500 mAh.
Any difference? I would like to get an extra one at least.


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