Yep, thats the one I bought.
Ezarc, was it one of these?
Oops, I didn’t read all the posts.
Well, something got screwed up in my USB port. Now it has infinite resistance. :( Everything else still works though. :) I'll probably just go back to EDCing a Goal Zero one.
No but that looks very interesting, any more info on it?
The one he has is solid white plastic and sits 4 AA side by side.
It's a Goal Zero battery charger. I got it with a 10 watt solar panel for 20 bucks at an REI attic sale. :D It will generally set you back 40-50 dollars. It is great quality, comes with 4 LSD batteries, and can charge off of a mini USB power source.
Oh yeah it has a 5 mm LED "flashlight". :P
There appear to be two different models here.
The Guide 10 Plus outputs 1.0A @ USB http://www.goalzero.com/shop/p/133/Guide-10-Plus-Battery-Pack/2:8/
The Guide 10 outputs only 500ma @ USB http://www.goalzero.com/shop/p/8/Guide-10-Battery-Pack/2:8/
This may be a factor depending on what you want to charge.
They look like nice units. Also some interesting solar panels as well.
As I understand it they are discontinuing the normal one because of some problems with it and the Guide 10 Plus will be the only one available. I may be mistaken though.
Simple answer is “don’t buy an iphone” or anything where the batteries are built in and not user-replaceable.
I have a Sansui DB-100 , DAB/MP3 player which has a built-in 1250mAh lithium battery … It is a pain in the bum , as the battery needs to be charged (in-situ) every week or so … The handbook says ten hours of playing with five hours of charge … It was bought in error as I thought the battery could be replaced easily … I am much more careful now when I buy … All part of the learning curve I suppose … Imagine having an AAA Torch with sealed-in battery … Ridiculous.
I did consider getting a portable charging device , but they are not very efficient … How many mAh would it take to charge (in my case) a 1250mAh battery … Whatever charging device you use will have to put out 5V to the Phone … So if it is using two AA batteries then it has to boost the voltage to five volts … Then the phone has to convert the 5V to about 4.2V to charge its Li-Ion battery … These conversions must introduce losses and have got to be inefficient.
I guess solar chargers have got to be the best way to go , but then again they are not exactly small … A decent amount of stored power in one of those portable chargers will also make the device heavy … I guess the portable charging device would need to have at least two 3100mAh Li-Ions in it to be of any use … Interesting problem isn’t it.
Luckily my Motorola mobile phone uses a BX40 battery and the spares are very small and easy to carry … If only my Sansui DAB/MP3 player was the same , life would be perfect …… Almost !
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Good point but most smartphones have a built in battery. My battery case which has a 1700 mah battery will give about 75% of a charge.
When without mains to plug in to, I use the ML102 charger as a backup charger for my smartphone battery (1500mAh). It is very small and one trustfire flames 2400mAh 18650 charges the phone battery from empty to 85%. It is actually a pretty decent charger for your 18650 batteries too, as tested by HKJ.
djozz
I’ve calculated efficiency on mine - assuming 44 Wh (I’m using 4x NCR18650A) on input, it gave out 6900mAh at 5.1V, which is voltage this box gives out under 1A load (0.5A is closer to 5.2V), so that’s 35 Wh.
Calculates to 79.5% of 44Wh, so I’d say that’s pretty efficient.
Some of the sellers on Ebay say that you are not to use protected 18650’s in these devices.
Other than the length , is there a reason to only use non-protected 18650’s ?
I don’t like the idea of putting four explosive devices (I mean 18650’s) in parallel in a plastic fragmentation case ! … I would want to have some protection on each individual cell (just in case).
I guess this device loaded with four 18650’s would cause some concern to the airport security as it was detected on their screens.
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I agree we loose some energy when converting from 3V to 5V, but it is acceptable for convenience.
As some members has stated, using external Li-ion cells are more dangerous, and may be a problem with airport security.
Using standard AA cells as a backup is better, because you can easily find alkalines on the go.
Also Li-ion external chargers need to be charged when empty, you can not easily swap their batteries.
Goal zero guide 10 plus product mentioned above is also better, because it uses 4 batteries, that makes 4.8V with Ni-Mh, 6V with alkaline. Booster will be more efficient, and it can charge a smartphone 2 times with 4 full batteries.
You can even make your own charger using 4 AA holder and 5V voltage regulator circuit.
I have made a charger using a car USB charger circuit (12V to 5V converting) and 6 AAA batteries.
It's funny djozz, I just emailed Hank at Intl-Outdoor about this very unit.
He tested and confirmed that it will input/output simultaneously which means you could use it as a buffer on a solar panel or charge your phone and an 18650 at the same time from one power supply. Nice and versatile!
Been doing a little research today and I have seen claims as high as 87% efficiency and tests as low as 50% efficiency for these kinds of Li-Ion to USB solutions. But as march.brown has said, in all these voltage conversions, there will be inefficiencies. For solar, it would be better to put the panel direct to the phone or other device.
However, whilst efficiency is surely an issue for wilderness trekking and solar solutions, our OP was only enquiring about generic portable power. I'm afraid I brought the solar comment into the thread.
This ML-102 unit really does seem to be ideal, especially if you can charge your 18650s at home and just take a bunch with you.
You don't actually need a 5 volt regulator circiut. USB is 5 volts +-.5 volts so 4.5-5.5. Nimhs will stay in that since they are 1.4 at full charge (5.6)(they drop quickly under load) and around 1.1 when dead. (4.4) Alkalines will also work fine due to voltage drop.
You are right it works with most of the devices, but I think it depends what device it charges.
Some device may require 5V under load, may cut off charging if it detects under voltage,
and a regulator is an insurance for possible high voltage to the device.
Do you know of any sources for 5 volt regulators? I had looked around but only found buck drivers, no boost.
LM2577 might suit you. It regulates 3V-35V to anything higher with min. 1V overhead (so, with fully charged 4.2V Li-Ion, output voltage will be 5.2V).
So it just boosts the voltage by on volt? Or is it configurable so it will keep it at 5 volts from 4.2-3.0?