On my last trip, I found myself in the horrible situation of being on a plane with no means of powering my various gadgets. Back in steerage (um, I mean "coach") on Continental, you can't count on having one of these 12V sockets anymore.
So I was thinking about a very lightweight battery pack with 2 or3 12v cigarette lighter outlets on it, powered by 4 CR123 batteries, and perhaps a powered USB port for those devices that charge via their USB cable.
As far as I can tell, there is no such device on the market yet.
Does anyone else have some input on this idea for a VERY light, airline-freindly power pack?

Why not try a power pack 2ah sealed pack with sig socket and charger.
Can't remember who made it power pocket I think its called.

Leemann <img src="/images/graemlins/cool.gif" alt="" />

Try a high end camera shop for battery packs.

Big problem is that battery packs look an awful lot like bundled explosives, and with what a good camera battery pack costs, you don't want to end up leaving it at the gate or trying to get another flight while getting your bags off the current flight to repack them.

Good luck!

Bountyhunter

Try powerportstore.com

Lee <img src="/images/graemlins/cool.gif" alt="" />

BoxWave Battery Adaptor might meet your needs. It uses 4 AA batteries, which they claim is good for 5 hour of charge for a PDA.

Hi!

There are quite a few products out there. For your needs (and location <img src="/images/graemlins/smile.gif" alt="" /> ) I'd recommend to check out ICP (icpsolar.com). Look for BattPak, and iSun. Not as lightweight as your idea, but much more versatile, economical, and enviromentally friendly.

For real emeregency use I would use readily exchangeable spare batteries for the critical units.

You can upgrade some APC (apcc.com) Travelport solutions (or such) also, but it is almost a complete mobile office. <img src="/images/graemlins/smile.gif" alt="" />

Hmm...
Perhaps I'm the only guy who thinks carrying lead onto an airplane is a bit silly. Lead-Acid batteries are not the way to go. I want a total packed weight for a battery pack to be under 1lb, it needs to be able to provide at least 3 amp-hours. A few CR 123's seem to be the only way to go if I want to be able to power up anything for a reasonable amount of time.

As you may recall, I refuse to check baggage, so every ounce I cut from my packing is vital.

Have a look at this. Maybe you can adapt it.

http://www.surefire.com/maxexp/main.pl?p...mp;amp;sesent=0,0

Thought that you might find this interesting.
I've bought one and tried it. It's not spectacular, but its functional. You can plug in a usb charger to charge your cellphone, pda, whatever. If the smallish int battery dies, you can always crank the charging handle to get some more juice.

The leds are not really that bright and the siren and flashing leds are just kinda cheesy.



Oomph VX8 Homepage

Martin,

Your specs are gonna be pretty difficult to meet... I think your best bet would be 4/3 A Sanyo NiMh rechargables in an 8 - 9 cell configuration running a regulated boost circuit to keep your voltage at a constant 12v. Your theory of using CR123 cells is feasible, but it will take a heck of a lot more than 4 cells and you'll still need a regulated boost circuit - expensive batteries. Read on and see why I say NiMH:

Depending on how close you need to be to 12v, with any chemistry you'll either need to add a few cells for a higher fresh voltage or include a boost/regulator circuit to keep output pumped up 12v as you use the batteries. Battery voltage starts dropping as soon as you start using them.

CR123 cells start at 3v and are usually considered exhausted around 2v. They typically have about 1500mah capacity, so that means you will need 8 of them, not 4, to get 3000 mah, and at the end you will be looking at 8v, not 12v. (Two 12v series packs wired in parallel gives you 3000mah at 12v) 8 cells come in about 4.8 oz naked, so your weight limit seems attainable. Lessee, that's about $8 - $10 a pop at discount mail order price. It may not be supremely reliable, though, because once in a while a single CR123 will go dead-nuts flat compared to its in-series companions.

L91 AA 1.5v lithiums have pretty close to the ampacity you spec - 2900 mah. That's at a steady discharge rate of 200ma. About 0.5oz each, it will take 9 to start out at 12v and the pack will be down to about 9v when the cells are consider to be exhausted. That's about $18 to reload and the naked cells add up to only 4.5 oz (1/2 oz each).

Alkalines look interesting at first. A standard E91 AA has 2850mah, standard E93 C has 8,350mah, E2 X91 AA has 3,125mah, and X93 C has 9,185mah - not too shabby. BUT those ampacities are at a discharge rate of only 25ma. They simply will not deliver anything close to that at a high discharge rate (they will benefit from "resting", but you'll never get those ampacities at high discharge rates no matter how you do it). And these cells are considered exhausted at 0.8v, so your "flat" voltage will be only 7.2v. Figure about 0.8oz each for the AAs and about 2.3oz each for the C - I figure you can make something work with a regulated boost circuit and 9 C cells at reasonable discharge rates, but just the naked cells will weigh more than your 1lbs. Some wizard can fiddle with it and figure out efficiencies, discharge rates, etc - maybe you could do it with fewer cells (boost circuit).

NiMh rechargeables look interesting. A gonzo AA NiMh is rated for 2100mah at 420ma discharge, starts at 1.2v fresh and at C/5 is down to 1.0v. About 1 oz., you can make your weight limit and have an ampacity of 2/3 what you want (10 cells, 10oz naked). C cells run close to 3oz each in case you were wondering... and the average ones have little more capacity than the gonzo AAs, although they can run upwards of 4,500mah. Better would be Sanyo 4/3 A size cells at 3800mah and 52 grams each (that's about 1.8oz, so 10 cells are a tic over 1lbs - but back to the boost circuit - you could drop one or two cells)

Build/have built a magic box using Sanyo 4/3A NiMh cells and it can be reliably done. Recharging is a whole other topic and this is already too long a post.

Disclaimer - no affiliation with Sanyo or anyone else. You can get larger capacity 4/3A cells from Sanyo, Varta, and others - not surprisingly, they weigh more...

HTH,

Tom