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[Mike Lee]

I just got done with a trial run using a Tekkeon MyPowerAll 3300 universal rechargable battery pack ($80) to power the XO. I got 8 1/2 hours of full screen brightness and mesh active! The Tekkeon drained first to empty, then I unplugged it and ran the XO battery from nearly full to the automatic cutoff. When power management is released in OLPC Update.1, I imagine the run time could increase by 100% or more. If I dim or turn off the backlight, the XO should be able to run for days. The power pack comes with a compatible power tip / plug "B". My product photos are on Flickr.

Next I will hook up my large solar panels to capture charge for nighttime use.

Here are reviews on Gadgeteer and Gear Diary. And Steve Paine's blog post about using the Tekkeon with solar panels.

~

[Tortuga]

Mike,
Did you happen to record the time for the XO's on its own battery ?

I'm really interested in the battery life of the XO on the LiFePO4 battery.

I posted about two reports on XO battery life which reported about 4 hrs for normal use and 5 hrs for eBook mode. Their protocol was different from what you reported.
http://olpcnews.com/forum/index.php?topic=1626.0

I did some rough calculations on what you posted and got something like 2.8 hrs for the XO  battery and 5.7 hrs for the Aux battery. Using 22.8 Watt-hours for the XO's battery(LiFePO4) and 40.0 Watt-hours for the Aux battery.

Does this sound about right, to what you observed/recorded?

[Mike Lee]

Your calculations seem in the ballpark. I average 3 to 3 1/2 hours of run time with my XO running at full screen brightness and with mesh on.

Correlating power measurements across XOs is hard because the power management was broken in many ways until mass production and somewhat broken until now. G1G1 people are running a mixed bag of OS and firmware versions. It was impossible for me to gauge battery run time on my B4 prototypes because I had a hardware problem where the laptop would suddenly turn off before the red light came on. Everything I've reported about since late December is based the mass production XOs I have.

I'll add that when the Tekkeon is attached, I don't get a charge symbol on the battery gauge in Sugar. The embedded controller just seems to treat the Tekkeon and the internal battery as one big battery. I think the voltage regulation on the motherboard of the XO makes the Tekkeon drain completely first, then begins to empty the internal battery. The gauge read 93% at that point.

Mike

[Tortuga]

Thanks for the additional information.
This is interesting:
"... when the Tekkeon is attached, I don't get a charge symbol on the battery gauge in Sugar. The embedded controller just seems to treat the Tekkeon and the internal battery as one big battery. I think the voltage regulation on the motherboard of the XO makes the Tekkeon drain completely first, then begins to empty the internal battery. The gauge read 93% at that point."

Here is a search engine that I have found useful, better than Google, for finding information on hand crank generators/chargers and such:

Global Spec, The engineering search engine
http://search.globalspec.com/Search?query=bicycle%20generator&n=10&show=total&pg=2

This article has an interesting approach on "how to make a hand crank DC generator using a standard 12, 14.4 or 18 Volt Cordless drill"

http://www.zetatalk.com/energy/tengy05n.htm

[CatMoran]

I couldn't resist -- newegg had a good price, so I bought a Tekkeon MP3450. It's basically the same as the 3300, just a little heavier, with more power capacity, and a higher maximum voltage.

I used it to power my XO at work today. Set at 12v output, it lasted slightly over 7 hours. The XO screen was at about 1/4 brightness and the CPU was busy playing movies all day. (The XO ran another 3 1/4 hours on its own battery after that.)

The MP3450 can also power the XO at the same time that it (the MP3450) is being charged. But it's a little tricky -- it has to be connected to the XO and powering it, before it's own charger can be connected. So if the Tekkeon is dead, you have to charge it for at least thirty minutes before it has enough power to start powering the XO.

It will also charge the XO's battery, possibly because it can output more voltage than the 3300. However, it won't start charging (vs just powering) the XO until the XO's battery falls below a certain point. I haven't figured out just what that point is yet, except that it's > 26% and < 93%.

Overall, it's not as simple and reliable as the XO's AC adapter. Or even an iGo 40 plus a 1amp AC-DC converter. But if you need the extra battery capacity and are short on luggage space, it seems that the MP3450 can double as a charger.

[Gleth]

Thanks for finding this. I got myself the MP3450 and now, for the price of one battery, I can extend the unplugged time of all my laptops. :-)

OK, it's only one at a time, but as someone who spends a fair few hours each year sitting in airports / planes without access to a power socket, this is a brilliant extra to have.

[Mike Lee]

Thanks for the reports on the 3450. My wife will decide to claim my 3300 one day soon, so I'll pick up the 3450 then. Not only does it have more power storage capacity, the addition of the built-in USB charging port will allow me to charge a iPod or iPhone while powering my XO.

[Gabey8]

I swear, these forums are getting expensive.I keep finding must-have accessories.

Seriously, as it appears I will be attending two conventions this year (three, if I can pull it off, lol) and I want to do the XO Road Warrior thing, I thought that the Takkeon would be a necessity, not a luxury. So I went for the 3450. It's a little late at night to test how long I can power the XO with it, so now that it's fully charged, I'll test it out tomorrow.

[Mike Lee]

Gabey8 (Donna!),

Do report back on how it goes with your shiny new Tekkeon. Since my last post, I got my order of extra Tekkeon connectors. I have one for my work issued Blackberry Curve and another that is a USB port into which any USB cable plug can be inserted. It's nice that the 3450 comes with an extra USB port.

Last week, I easily ran my XO for 6 hours of notetaking at the Children's Mobile Workshop where David Cavallo and Walter Bender of OLPC spoke. I just ran my fully charged XO until it got to the red zone, then plugged in the Tekkeon 3300. The XO charged up in seemingly the same amount of time as the AC adapter as I kept typing.

Tonight, the Tekkeon is packed in my carry on bag for a flight later this morning from DC to Monterey. It should run my XO and Asus Eee PC quite easily. For the first time in a while, I'm not taking my MacBook to a multi-day conference, just the two small laptops.

I recall you have the Power Pocket foldable solar panel. You should have the proper connector to have the panel charge the Tekkeon...

Mike

[LaPaglia]

Mike,

You can get more total time out of the two devices by reversing your order. By discharging the XO first you pull the operating current AND the charging current out of the Tekkeon when you plug in the Tekkeon. If you use the Tekkeon first on a fully charged XO you will get a longer total run time as the Tekkeon will only be running the XO and not charging the battery at the same time. It might be only 20 minutes but there have been times when I would kill for an extra 10 minutes of battery time.

Just an idea.

[Gleth]

Under constant use I found the 3450 and XO combined got 9 hours 20 minutes use before I had to go home for the day. The XO was displaying over 10% left and going strong, so I thought I probably could have got to the 10 hour mark... not bad at all, and with the new builds getting a far better reported battery life I'm thinking I only need my XO and the 3450 on a day out. :-)

Have Fun,
Gleth

[Mike Lee]

Following up... I got a Tekkeon 3450 a couple weeks ago. I love it. With the USB port, it can power all my lower power devices like cellphone, iPod, e-book, etc. The included tips power the OLPC XO and Asus Eee PC. I also like the slimmer slipcase that's included. One negative is the whopper-sized 60 watt AC adapter.

[Gabey8]

I noticed tonight that if I wanted, I could take the XO semi-off-the-grid with the Tekkeon 3450.

I was using the XO this afternoon while it was fully charged and plugged into the Tekkeon battery. At 8:35 PM, the Tekkeon battery was exhausted and its LED went off. The corresponding battery LED on the XO also went off. I plugged the Tekkeon in to  recharge it and continued surfing.

At approximately 10:50 PM, the Tekkeon's LED went from red-orange to green, meaning that it was fully charged. The XO battery was still at 28% at the time.

If I wanted to, I could plug the Tekkeon right back in when the XO's battery eventually is exhausted. That will mean a shorter lifespan for both batteries combined than the 10 hours I normally get when I start with both batteries at full charge and plug the Tekkeon into the XO. But it would most certainly run the XO as well as charge its battery.

So IMO, I'm only halfway off the grid, since I still have to plug in the Tekkeon battery. But the good news is, I can use the Tekkeon to run the XO without having to plug the *XO* in. If I ever experience problems with the XO charger or battery, it's nice to know there's a workaround available.

[Donna]

For those who have used the Tekkeon external power supply with the XO Laptop, and have looked into recharging the Tekkeon with a flexible solar panel, please post your findings.  I am experimenting with that configuration at this time.

Thanks,
Donna

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