[pct-l] USB device charging

Thomas Jamrog balrog at midcoast.com
Thu Mar 18 06:29:36 CDT 2010 

Thanks for the tip on the shorter cable, I just ordered one.  I have had good results with my iPod Touch (just like the iPhone in most ways but without the monthly phone charges)  using  the Solio classic solar charger, which also serves as a storage battery when charged up via the wall plug.  I get two charges of the iPod Touch with it.  You can also use the sun to recharge the unit if you hike in those conditions.  The numbers are :  1650Amh, 5-6V , 800 mA output range,  4.8 watts. There is also a special adapter you need to buy from Solio that mates between the Ipod Touch or iPhone and the plug coming out of the Solio unit.  
Uncle Tom  
 

 
Read all about it right now ( hotlinked)  at  www.trailjournals.com .

On Mar 17, 2010, at 3:08 PM, Bill Burge wrote:

> 
> I didn't write the following for PCT hiking, but it might prove useful:
> 
> I started with a short cable because it seemed silly to carry a long  
> cable with me all the time.  Because of the case I use, "cableless"  
> options (built-in connector) are not an option.  Also, many of those  
> are rigid or have a case for the phone.  I like my case and making my  
> phone 2-3 inches longer makes the connector in the phone the break  
> point if it flexes!
> 
> ProCable Shortz  in 7cm (2.5") or 20cm (7.5"), a few different places  
> carry them, this is an example:
> http://www.radtech.us/Products/CablesiPod.aspx#ProCableShortz
> 
> I have the 7cm, and a retractable USB extension (that I bought at  
> Fry's).  I bought the short cable from Radtech, but other places carry  
> them.  They are a good company with great support.
> 
> For batteries, that's more complicated.  Many battery suppliers don't  
> publish the capacity of their battery packs and some that do (Lenmar)  
> overstate them drastically.  Many wish to say crap like "recharge your  
> device 3-4 times" - WHICH device?  My old iPod, my BlackBerry, my  
> iPhone 3Gs?  Others are even worse with "adds 27 hours of talk time!"   
> WTF does that mean?  "My iPod Touch has 0 hours so far, so now it has  
> 27?"
> 
> So I deal in "mAh".  That says, if you're not into battery juice,  
> "this battery will put out the stated voltage (in this case, USB spec,  
> which is 5-5.5V) at so many milliamps for one hour or 1 milliamp for  
> so many hours and anywhere in between. So, an iPhone 3Gs battery is  
> 3.7V and 1220mhA.  Simplistically, we'll call that 4514VmAh as the  
> capacity of the battery.  In a perfect world, you'd need a charger  
> battery that put out that much energy to fill it back up, but you will  
> actually need more.  There is loss and power used to drive the  
> circuitry to charge the battery and change the voltage inside the  
> battery pack from what ever it is to 5V for USB output.  Since USB  
> output is 5V, a battery pack of 903mAh is one charge of the iPhone  
> 3Gs.  Let's round to 1000mAh of USB power for a full charge.
> 
> The other item to be on the lookout for is the rated output power in  
> milliamps (mA) or amps (A).  USB port output for running attached  
> devices is about 500mA at 5V (so 2500VmAh).  If a device like the  
> iPhone 3Gs needs 4514VmAh to fully charge, then at 5V and 500mA, it  
> will need about 1.8 hours to charge - about 2 hours with loss, etc.   
> Some chargers are offering 1000mA (also called 1A, or high output)  
> charging ports for devices that can use the extra juice.  I believe  
> that older iPods (and maybe the original iPhones) are limited to  
> drawing 500-ish mA from the port.  The iPhone 3Gs will do a "fast  
> charge" if it detects a "high output" port.
> 
> I have a Lenmar battery pack that claims to be 750mAh, it makes about  
> 30% charge of the iPhone.
> http://www.radioshack.com/product/index.jsp?productId=3184995  nowhere  
> NEAR 750mAh, but I got a couple at Fry's on sale for less than $10.   
> Very small and can carry in my pocket with my short cable for an  
> emergency.  (No high output port, I can use the iPhone faster than it  
> can charge it; in some situations.)
> 
> I bought this one for Helen as a bigger battery.
> http://www.radioshack.com/product/index.jsp?productId=3912660   It  
> claims 2100mAh and should be able to charge the iPhone 3Gs twice!  Not  
> so, once and some change.  I bought it at Fry's and didn't get such a  
> good deal.  Both of the Lenmars came with Apple cables, don't use  
> them, they won't work with the iPhone or some later model iPods.   
> Apple changed the spec of their cables...  (Again, no high output port.)
> 
> My current favorite battery is making me frustrated.  It's the  
> Duracell "Instant USB Charger".
> http://www.duracell.com/en-US/product/instant-usb-charger.jspx  I  
> bought it at WalMart for $20, on a whim, and it's turned out to be my  
> "pocket favorite".  It's very flat, so it's good for the pocket.  At  
> $20, it was a bargain!  It advertises 1120mAh and DOES do a "flat to  
> full" charge of my iPhone 3Gs.  Ever since, when I see them - they are  
> $30 - not as much of a bargain.  Some of the things I DO like about  
> it, it comes with a very short (portable) power/recharge USB cable AND  
> is has an actual ON/OFF switch.  Most of these types of devices do  
> NOT, and as such are always powering the power conversion circuit and  
> slowly draining.  Very slowly, but draining just the same.  Also, it  
> seems that it does put out more than the minimum for a faster charge.   
> This one is so small and flat that I might consider hiking with more  
> than one and call it "done", but then I start getting cheap...
> 
> Then there's BIG juice.  This would be for something like the bus ride  
> to camp and back.  Usually, I'd be in a car with a 12V->USB adapter.   
> I wasn't on the charter to Joshua Tree so I don't know if there was  
> any power on the bus for devices, so do have that. But I go looking  
> and I did order something.  I can't vouch for it's performance yet.
> 
> I considered looking for the larger Duracell.  The Powerhouse Charger:
> http://www.duracell.com/en-US/product/powerhouse-usb-charger.jspx  but  
> at 2000mAh, it would be two charges at best and was not that  
> compelling, unless I could find it deeply discounted.  I could not.
> 
> I considered something VERY expensive, but with other uses for after  
> Snow Camp, and of very high quality:
> http://www.hypershop.com/HyperMac-External-MacBook-Battery-100Wh-p/mbp-100.htm 
>  but just couldn't bring myself to cough up the bucks (still, it  
> would charge the iPhone over 50 times! ;-) Definitely a 1A, high  
> output, power port.  I could power my laptop on some car/plane trips  
> and power my iPhone as well.
> 
> The same company has a device meant more for iPhone/iPod use, and I  
> considered it as well:
> http://www.hypershop.com/product-p/hm36-black.htm still pricey for  
> 3600mAh (about 3.5 full charges) but very good quality and probaby IS  
> 3600mAh!  Definitely has a 1A, high output power port. (May still get  
> something from these guys, if I get a bonus at work or something!)
> 
> What I ended up ordering was:
> http://www.imaxpower.com/IMP500-3G-3Gs-iPhone-iTouch-external-battery-p/imp500.htm
> I liked that it came with a "wall wart" charger that I use for it or  
> for my iPhone or iPod Touch.  I doubt that the cable will work for  
> either.  I purchased it through Amazon, last night, and it shipped  
> this morning.  I'll let you know how it does when I get it.  The  
> online reviews have said 4+ full recharges of iPhones and a charge  
> rate that implies a high output port and a 3rd party doc "confirms"  
> it.  I verified with the vendor that the capacity is 5000mAh at 5V, so 4  
> full charges should be expected with some power left over.  At 130g,  
> this might be "trailable" at about 1oz per iPhone charge.
> Reviews:  http://forums.macrumors.com/showthread.php?t=565215 and
> 
> I was going to get http://www.imaxpower.com/product-p/imp880.htm to  
> share (with GF), but then what happens to is after the trip is over?   
> This device probably has a high output port, but now I'm not so sure...
> 
> BillB
> 
> 
> 
> On Mar 17, 2010, at 11:17 AM, Jim Keener ( J J ) wrote:
> 
>> Greetings,
>> 
>> I received this charger yesterday and tested it today on a fully  
>> discharged iPhone 3GS. It charged up to 82% of the iPhone's battery  
>> capacity and ran out of juice. Bad charger.
>> 
>> Walk well,
>> Jim Keener ( J J )
>> _________________
>> 
>> jj at ridgetrailhiker.com
>> 
>> http://postholer.com/jj
>> http://ridgetrailhiker.com
>> http://olderhealthier.com
>> 
>> 
>> 
>> 
>> 
>> 
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