[pct-l] USB device charging
Bill Burge
bill at burge.com
Thu Mar 18 10:02:26 CDT 2010
I originally looked at this device. If I see one at Walmart for that
price I will probably buy it just for testing.
You're right about the price, but:
- it weighs 50% more than the one I bought and has LESS than half the
capacity. It is also a slow charge - 500mAh.
Actually, nowhere does anyone publish the capacity so this is based on
relative charge requirements of ipods vs iphones, if you can pop the
battery cover and give me the numbers - I'd like to know... The
original poster said he got 80% charge, which would imply the capacity
at 900mAh, like the model number "900-72". That would put it at less
than 25% of the capacity of the IMP-500. I just got my IMaxPower
IMP-500 last night and will be testing it over the next few days...
- it has gotten some VERY mixed reviews, including the on that started
this topic
You didn't have to bounce the charger (like you would with the IMP,
though it is very small) but you did have to carry it with you every
day.
BillB
On Mar 18, 2010, at 6:08 AM, Joshua M wrote:
> Fully charges an ipod twice, has two usb female ports. When in town
> you can
> charge 2 devices and the internal battery at once. You can carry an
> optional extra batter if you are using a lot of power. Carried it
> 2000
> miles, works great and you can't beat the price.
> http://www.amazon.com/Music-Power-0900-72-Rechargeable-Extended/dp/B000QFNK6K/ref=sr_1_1?ie=UTF8&s=hi&qid=1268917528&sr=8-1
>
> On Thu, Mar 18, 2010 at 7:29 AM, Thomas Jamrog <balrog at midcoast.com>
> wrote:
>
>> 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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