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?

Re: External battery use
 

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.

Re: Exteral battery use
 

Hi Karel,

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

Re: Exteral battery use
 

Mine uses 4 AA batteries... :p

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.

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.

Re: Exteral battery use
 

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...

Re: Exteral battery use
 

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.

Re: Exteral battery use
 

Hi Karel,

I think a simple regulator circuit would do the trick.


Luke

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.

Re: Exteral battery use
 

Here is what I use http://www.newegg.com/Product/Produc...82E16875999020

Works great and will even recharge the AA batteries via a USB port. Comes with a tip that works with the 770 which I assume is the same for the N800. Plus there are a bunch of other tips that come with the product for use with other devices, such as cell phones. While it charges the Nokia, it does so very slowly and I find it better used to supplement the on-board battery.

Re: Exteral battery use
 

Yeah. You know, I actually almost understood some of the words in that sentence. :rolleyes:

That should give you an idea how proficient I am with electronic parts. I'll probably wait a few months and let some Thai electronics genius figure it out for me. ;)

Re: Exteral battery use
 

I I didn't know about the other battery. My n800 is using the BP-5L, and I seem to be getting the full battery life. I, like Karel. couldn't tell a capacitator from a regulator if me life depended on it,

Re: Exteral battery use
 

a regulator circuit isn't complex...parts should be available at ratshack or online for sure... google it.. here is a sample..
http://www.tkk.fi/Misc/Electronics/circuits/psu_5v.html