Re: External battery pack for N8x0/770.
 

Thank you, please let us know your findings asap!

Re: External battery pack for N8x0/770.
 

No results yet - test just started. Both internal battery and MP1550 are fully charged and connected. Im running mplayer in the following loop in an xterm.

while [ 1 ]; do date > last.txt; mplayer n800.avi; sleep 10; done

(cant remember the full name of n800.avi - its the default video in OS2008).

If its not still going tomorrow then last.txt should show how long it was running for.

Re: External battery pack for N8x0/770.
 

Thanks a lot! I can't wait to see the results!

Re: External battery pack for N8x0/770.
 

mplayer ran continuously from 8:25pm to 5:22am - so thats just shy of 9 hours.

It might be possible to get longer if I waited until the battery was lower (i.e. 50%) before activating the battery pack.

Re: External battery pack for N8x0/770.
 

Wow, that's REALLY good for a cheap battery pack!

Re: External battery pack for N8x0/770.
 

I think I read somewhere the external packs are more efficient when used with a fully charged internal battery, the rationale being that charging the internal battery is a less efficient process than delivering current directly (which is -- more or less -- the case with a fully charged internal battery).

Don't shoot me if your Itablet explodes.

Well, you wouldn't -- because you would have exploded as well. So the disclaimer is pretty redundant then. Pfhew...

Re: External battery pack for N8x0/770.
 

I'm going to have to try that with my Tekkeon MP3300. I use it for both my n800 and DSLR.

Results:
The Tekkeon MP3300 has a row of 8 LEDs which indicate, what voltage is selected, and, at the press of a button, how much battery charge is remaining. My test was run using a 56 minute video (avi) of the Boeing 787 roll out. I also left wifi turned on (so omweather could update :D and a little use of ssh and sftp to the n800 from my PC).

After 12 hours of running the video, three of the eight LEDs on the Tekkeon were still lit up, indicating around 37% battery left, and my n800's battery was still fully charged.

It wouldn't surprise me if I got 18 to 20 hours total use out of the Tekkeon and the n800's internal battery.

(gee, I wonder how many pictures I could take with my DSLR?) :cool:

MP1550 external battery test
 

Hi all,


I hope that you don't mind my jumping in here with my experience with the Tekkeon MP1550 TekCharge. I recently purchased it on January 3 from Maxwho.com for $28.99 delivered. It arrived on January 8.

I decided to use eneloop AA batteries in the unit since I've had good results with them in the past with my digital SLR camera. Their low self-discharge rate makes them a good choice to power the MP1550, in my opinion. So far, what I've seen of the unit seems to make it ideal as a backup power supply. The construction seems solid, and with the included adapters, it can handle a lot more than just the Nokia Internet Tablets. Although I've only tested the hookup with my cell phone, which worked nicely.

Last night I thought that I would test the endurance of the unit while powering my Nokia N800. I've had my N800 for about a month and it is using OS2008.

I topped off the batteries of the N800 using the normal charger, and connected it to my home wifi network. I loaded a web page that would occasionally ask for new data without my intervention (The local Nexrad radar page on weatherunderground.com.) since I would be asleep through much of this. Admittedly this was not working the N800/MP1550 too hard, especially since the screen blanks after 5 minutes. I then removed the N800 from the charger and plugged in the recently fully-charged MP1550. (All three capacity indicators showing green.) Within a minute the N800 indicated that it's battery was once again fully charged. I then went to sleep.

This morning, at the 10 hour mark, when tapping the N800 battery indicator, it continued to read, "Battery full..." and the MP1550 showed three green capacity lights also.

At about 11 hours since the start, I noticed that one of the 3 capacity lights on the MP1550 had started to flicker. And at 11.25 hours, there were two capacity lights showing on the MP1550 and the N800 remained fully charged. Interestingly, it went back up to three lights soon after I stopped checking the N800 status.

At the 11.5 hour, I decided to push it a bit harder by playing a song in a loop in the N800 media player. Output was through a set of small earphones and the volume set on full in the player and half at the N800 main volume control. At 11.75 hours, there were two steady lights and one flickering.

At the 12 hour mark, the N800 showed fully charged and the MP1550 showed two steady green and one flickering capacity light.

As I write this at the 12.25 hour mark, the MP1550 is showing two steady green capacity lights and, of course, the N800 is fully charged.

I'll continue with this test until the N800 goes back to its own battery (the MP1550 is discharged) or 24 hours, whichever comes first and report back. But so far the MP1550 seems to be extending the battery life of the N800 by quite a bit. However, I'm not really pushing it too hard considering the screen dims, then blanks after 5 minutes. But, if the MP1550 were to go dead right now, there would remain the normal full battery time of the N800.

So for my normal usage, this appears to be a nice backup battery solution.


Bill

EDIT: 15 hours since the start... 1 capacity light remains on the MP1550.

15.25 hours: That was quick... from 2 lights to one to none. MP1550 is discharged and the N800 is on its own, with battery showing: When idle 10 days, When in use 7 hours.

Re: External battery pack for N8x0/770.
 

That's not backup, that's freaking steroids!

Re: External battery pack for N8x0/770.
 

These are two very interesting observations.

N800 Fully Charged battery + Tekkeon 3300 = 18 to 20 hours use
N800 Fully Charged Battery + Tekkeon 1550 = 12.5 hours minimum.

The price difference between the two models is about $100 so I would not have expected the cheapie to be so good.

Itsbill, let us know the final figure?