Here's a new product that apparently has been used by Israeli military and is now in consumer pre-marketing/pre-order. The responses cover some of the questions and plusses/minuses if you scroll down. Might be worthwhile for a long trip. Would be interested in responses of techies here.
Since the company is embarrassed about publishing its specs (like voltage and mAhrs), I will stay away. But Looking at what they do claim: 30 hours of talk time on a cell phone. Analyzing: 1. A Nokia 2760 uses a standard BL-4B battery. They claim 7 hours talk time. The battery is 3.7V @ 700mAHr or 2.59Whr. To go 30 hours, let’s multiply that Whr x 5 to get 35 hours talk time; or 13 Whr. A Lithium AA is 2.9Ahr or 1.5x2.9= 4.35Whr; so we need 3 or 4 lithium AA’s to run this phone for 30+ hours.
Now I get my lithium AA’s at Sam’s club for $1.67 each or $6.68 for 4. This company wants $20. So they will have to cut their cost by 4 to make it tempting for everyone.
2. If only ˝ the charge of the fuel cell is used and then stored for a couple of months--- well that went to waist.
3. Another option is buy five 2500mA 1.2V NiHM batteries. That would give you 30 hours after 1 charge! And they can be recharged 500 more times and each battery costs $2.00 and a decent charger costs $10.00
I think the comments on the website are spot on. This thing is still basically just a battery. It uses chemicals to generate electricity. A better fuel cell would have a way to top off the fuel, this does not. What does this do that a battery cannot?? It's also more expensive than a battery and it cannot be recharged. At least it can be recycled.
Barry has a good point. I want specs. Total mAh and voltage at the very least. When I go out in the field I know exactly how much food, water and stove fuel I have to meet my needs. I want to know how much power too.
And it needs a better variety of connecters to make it more versatile.
I just ordered one of these from REI. Granted it costs 5 times as much as this fuel cell but it is not a one use device. The power it provides is virtually endless. And it is much more versatile.
Anyone could buy a small thin film solar panel that weighs a few grams, a couple of NiMh cells, a diode and a battery holder for well under $30.00 and build their own solar charger which could easily be lighter and more practical than a fuel cell, and also produce a lot more power over time.
Edit: This is what I'm talking about. Its output is optimized to recharge 2 AA cells, or AAA's would fully charge even faster. A 2 AA or 2 AAA batter holder costs about $1.50. If you don't want to solder just use wires with alligator clips. All you have to do is get the polarity right.
I'm making a charger using two of these panels wired in parallel for a 200mA output. The whole thing will weigh as much as 4 AAA primary cells. I plan to use it on the TRT this summer so I can run my GPS all day long for 8 days and still have juice for my flashlight and MP3 player. If my numbers are correct it will fully charge a couple of 900Ah NiMH AAA's in 4-6 hours depending on the sun(keeping in mind the cells are never fully discharged). It will attach to my pack while I'm hiking and a 2' wire will lead to the cells inside my pack to keep them cool and out of direct sun. With any kind of reasonable sunlight it will charge one set of AAA's faster than my Foretrex 101 can discharge the other set.
Here's a rechargable backup battery that weighs a bit over three ounces. Check out the details:
American Power Conversion Mobile Power Pack's design complements mobile devices including MP3 players, mobile phones and portable gaming systems. Smaller than a deck of cards, this innovative device delivers hours of extra battery power for those gadgets consumers need most while on the go.
APC utilizes lithium polymer battery cells, an advanced battery technology with a higher power density than traditional lithium ion cells, to create a compact solution with high power output. Compatible with a wide range of mobile devices, the Mobile Power Pack can generate up to 55 hours of additional music time for an MP3 device such as the iPod® Nano, and 8 to 10 hours of additional email and talk time for smartphones, such as a BlackBerry®or Palm® Treo™.
The product includes the Mobile Power Pack, an AC to USB power adapter, and a USB to Mini B power cable. The Mobile Power Pack charges most mobile devices using the manufacturer cables; however, APC recommends the use of APC’s USB Charging Cables (sold separately) to ensure compatibility. Currently available in North America, the Mobile Power Pack (UPB10) carries an estimated resale price of $69.99. For more information about APC and its other innovative mobile solutions, please call 800-877-4080 or visit APC’s website at www.apc.com. http://apc.com/solutions/display.cfm?id=CD8265AE-5056-AE36-FEB38A00EA494C4D
Loc: Sunnyvale, Ca
Not sure where you get your 1.2 nimh batteries and charger but I can get 4 1.2V 2000mah plus a small charger for 12.99( 4.99 on sale -once a yr) and 4 pack of 2300 at 9.99 - all Lexmar brand at Fry's Electronics. The 2300's last about 4-5 wks and 150 pictures during that time.
P.S. If you want a simple charger for batteries. You can use a Malibu solar light w/ the control circuit to recharge a half drained battery. They come with 2 600mah batteries. I get two lights for 8.50 at Big lots
“Not sure where you get your 1.2 nimh batteries and charger but I can get 4 1.2V 2000mah plus a small charger for 12.99( 4.99 on sale -once a yr) and 4 pack of 2300 at 9.99 - all Lexmar brand at Fry's Electronics. The 2300's last about 4-5 wks and 150 pictures during that time.”
Hi Mike, Some of my battery thoughts: I got my 2500mAh batteries at Walmart. They run $8 (Kodack) to $10 (Energizer) for a 4-pack. I’ve tested their Kodak and Energizer batteries. I’ve also tested their 2650mAh Duracell rechargeables. In high current applications (camera, fenix CREE LED) you would think the Duracell’s would do better, but they have 10% less capacity than the Kodack and Energizer. Duracell might have their claimed 2650mah capacity at low currents but I haven’t tested that.
I would stay away from 2000mAh since they have less run time. Out on the trail, you would like the charge to last as long as possible.
As far as chargers, I’ve been impressed with the Energizer’s slow charger ($10 from Walmart). It’s best to use this charger when the battery drops <1.1V. The reason is it’s a timed charger (with some other fancy features). Timed chargers end up giving me the best charge and longest battery life. Trickle chargers sound nice. They claim to keep the “battery topped off”. However, I have found this shortens the life so that you don’t get your full 500 charges.
Fast chargers also shorten battery life and run time.
I have been fascinated with what Toyota has done with their 300-500V NiMh batteries in their Prius. They claim to only keep the battery charged to 90% capacity (or somewhere around that mark). They then theoretically last forever. I have 151,000 miles on my 2002 Prius battery and I have seen no drop in mpg.
Loc: Sunnyvale, Ca
You maded some good points on charging batteries, yes its true you can cut the life in half from fast charging.
I do R/C electric flying and have use old motorola cell phone packs( 4-5 1200mah batt's or lithuim cells) and made my own electric R/C airplane pack and I have a Lithuim, nicad and nimh charger from hobbico for electric R/C airplanes and have made some Lithuim -ion packs. I charge them at 500 - 1( 1 A) mah depending on the capacity.
The old cell phones I was getting at a electronics surplus for $1 a pack so 4-5 nimhs( Toshiba) and 1 lithuim cell( 3.6V) using them just for R/C.
Best thing to do with any new nimh is to cycle them 3-4 times before any long term use to get the best performance.
I heard 2 yrs ago college students where using Lithuim pack for use in a electric car and at the same time a hydrogen cell was being tested for laptop use.
Tom, since you're looking at Minty Boost may I assume that you need a female USB connector for your new Mp3 player?
If so consider this. I have one charging my Ipod right now. 3.4 ounces with four AAA NiMH cells. It can also serve as a USB powered battery charger and it has a nifty flashlight to boot!!! All for the princely sum of $9.06 shipped. I would not use lithium cells in it because the output is unregulated and the higher voltage of lithium cells (x4) could fry your device. USB voltage is about 5.0 Mnd this would put out 6.8 volts on lithiums.
Also I bought something like this at Wal-Mart for $10.00. Look in the camera section. It's bigger but 4xAA is lots of power for your Mp3 player.
The trouble is, 2 cells (especially NiMH) just don't produce enough voltage to power a USB port. Hence the need for the electronics, which are not 100% efficient and rob you of a little power. But four cells will do the job without needing an electronic boost.
If the above are too large and you have an Ipod this could work. Same idea as the Minty and already built for you. If you don't have an Ipod it could possibly be modified to work with whatever player you have depending on its power requirements. And modifying this would be simpler/cheaper than building a Minty Boost.
Solar charging while backpacking was discussed in another thread. I think the consensus was that it's simpler/lighter/cheaper to just carry extra cells unless you're guaranteed lots and lots of sun all day and you're actually out in that sun (or your charger is) which is hard to do on the fly.
Loc: Marina del Rey,CA
TR-those all look interesting. The Minty Booster looks like a homemade version. The kit is about $20, so economy of scale obviously makes a difference. If the Ipod one had a USB port instead of the Apple connector, it would be almost perfect.
There probably is one out there for about the same price. Just a matter of looking, I suppose.
I saw some solar chargers online as well for about $20 or so. Some of them charge AA's, so for a long trip, a charger, plus a AA to USB adapter/charger would run a small MP3 player for a long time.
My little player is a Sansa Clip-only 2G, but it also has a radio, which I wanted, so for me, that is enough. It will hold about 500 songs, which to me seems like a lot. More than I would be listening to on one trip, even if it was a week or so.
Don't get me started, you know how I get.