18650 Cell Phone Charger

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KiwiMark said:
Sounds tempting - how many batteries can you use? If it is 1 - 4 as you wish then I might buy one.
For charging - is this one channel? How many at a time - 1 to 4 or 1 only or 4 only or what?

I'm always interested in more options, I've got plenty of rechargeable batteries that could be used to provide power to the cellphone.
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Use only 1 or up to 4 18650's. I use 4 2200's, so it is a 8800mah usb power supply/charger.

Cells are in parallel, so they all charge at once, I guess a 4 slot 1 channel.
Has a td4056 chip for charge regulation, so it is a true CC/CV algorithm.

With a 1amp 5v input, it takes about 3 hours with a depleted 2200mah cell, with 4 of them it takes around 15 hours and terms at 4.15v
 
Lightfoot98 said:
Here is what I use. I have 3 of them, Works great.
Enough room in box for either protected cells or unprotected cells.

For charging into it from a 5v source, uses the TP4056 chip which is a true CC/CV algorithm.
I also use it as a stand-alone 18650 charger.

http://cgi.ebay.com/1-5A-Output-Mob...414?pt=LH_DefaultDomain_0&hash=item4159a04af6


This one has the data ident on pins 2 and 3 for ipads and iphones:

http://cgi.ebay.com/5V-Mobile-Power...153?pt=LH_DefaultDomain_0&hash=item45fafd98d1
Click to expand...

I've been looking for something just like this. Thanks for the link!
 
Lightfoot98 said:
Use only 1 or up to 4 18650's. I use 4 2200's, so it is a 8800mah usb power supply/charger.

Cells are in parallel, so they all charge at once, I guess a 4 slot 1 channel.
Has a td4056 chip for charge regulation, so it is a true CC/CV algorithm.

With a 1amp 5v input, it takes about 3 hours with a depleted 2200mah cell, with 4 of them it takes around 15 hours and terms at 4.15v
Click to expand...

That sounds pretty good, I can see a big advantage in putting 4 cells in parallel - even 1/4 charged they could still fully charge a flat phone. You could even put in 4 x 3,100mAh cells for 12,400mAh of capacity. That's why I just ordered a couple.
 
malow said:
just measured:

Vin: 4.0v = 83% efficiency :thumbsup:
Vin: 1.2v = 48% efficiency :sick2:
Click to expand...

Interpolating those figures shows that even at ~3V (flat Li-ion) the efficiency would still be pretty reasonable. At over 65% efficiency (seems likely) it wouldn't be hard to get a 2400mAh 18650 cell to fully charge a flat 1300mAh cellphone battery.

I have a cheap charger that uses a 1 x AA cell to charge a cellphone - it is a good way to drain AA cells, but it is barely able to get 1/4 charge into a cellphone battery from 1 fully charged AA cell. My 2 x AA Sanyo Eneloop Stick charger does better (if it uses something similar to your charger's circuitry the voltage of 2 AA batteries would provide better efficiency than a 1 x AA charger) but wouldn't get much more than 50% charge into a cellphone.

One advantage of my Eneloop Stick charger is that it can use AA batteries, which is handy if they are what you have available. Running from ~2.4V should mean OK efficiency too. My cheapie 1 x AA charger DOES get very hot - 48% efficiency could easily be right for that one.

Overall these cellphone chargers that run from Li-ion cells seem like a good choice, it seems likely that the less the voltage needs to be stepped up the greater the efficiency. There is also the fact that 18650 cells have VERY good power density. Because of this I'm really happy with my $16.20 charger - for the size & weight of this it is a great option for fully charging my cellphone even when camping and no where near a power source.
 
KiwiMark said:
I must say - the included battery is junk, I tested it with my hobby charger and got ~1200mAh out of it. It may provide more capacity at a lower rate, but I can't see it providing anything close to the 2400mAh that the wrapper claims.
Click to expand...

OK, I've done another test on this cell. For the benefit of anyone that buys one of these DX units - this battery is complete junk, it is not worth taking it with you to charge from!
I fully charged it (to 4.2V CC/CV staring at 1A cutting off once the CV stage current dropped to 0.1A) and then discharged it at 0.5A down to 3.0V - I got 1300mAh out of it. :thumbsdow
This cell is a pile of excrement!

I think this battery would only half charge my phone, but a good 18650 cell would be able to fully charge my phone. Even the Trustfire cells from DX which sell for $10 a pair are MUCH better than this and there are plenty of other options (including AW).

The bottom line on the included cell is that the charger would need 100% efficiency to charge my phone from this, but for the same size and approximately the same weight there are plenty of cells that will hold twice the power.
I still think that for $16.20 this unit is excellent and for the size & weight of it you can't beat it for what it can do (with a good 18650 cell).
 
Re: Looking for portable 18650 charger for phone

Lightfoot: I saw one of those listed, but thought it would be more bulky than I was willing to cart around. I ended up going the DIY Mintyboost route. I put the kit into the charger I bought but was disappointed with. I stripped out all of the internals and replaced it with new. It doesn't currently recharge the 18650, but I'm looking into a separate charging circuit (and an LED voltage meter) depending on how much room I can find inside the host. I had to mount the caps and inductor laying down because there isn't much vertical room. Anyway, I now have a portable USB port to charge whatever I need to on the go.

http://i.imgur.com/HM486.jpg


Your image is too large and has been replaced with a link. Please resize and repost.
See Rule #3 If you post an image in your post, please downsize the image to no larger than 800 x 800 pixels. - Thanks Norm
 
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Lightfoot98 said:
For charging into it from a 5v source, uses the TP4056 chip which is a true CC/CV algorithm.
I also use it as a stand-alone 18650 charger.

http://cgi.ebay.com/1-5A-Output-Mob...414?pt=LH_DefaultDomain_0&hash=item4159a04af6
Click to expand...

KiwiMark said:
That sounds pretty good, I can see a big advantage in putting 4 cells in parallel - even 1/4 charged they could still fully charge a flat phone. You could even put in 4 x 3,100mAh cells for 12,400mAh of capacity. That's why I just ordered a couple.
Click to expand...

They say 15-45 days for shipping, but it has been 7 days and my 2 mobile power boxes have arrived already! I'm playing with one now, seems to be working exactly as described. For the size of the unit it is brilliant - with 4 x 2400mAh Trustfire cells (ten bucks a pair, so I'm talking about $20 worth of batteries including international shipping) you get almost 10Ah/37Wh of batteries in a not very big box. I'd be surprised if this box couldn't easily charge my cell phone from dead flat to full 100% at least 4 times - that's pretty darned good!

I got a couple of those Trustfire cells: http://www.dealextreme.com/p/trustf...h-rechargeable-lithium-batteries-2-pack-20392
After testing I've ordered another pair, I might get more later too. These cells easily hold 2400mAh, I had no problem pulling almost 2500mAh out of one using a 0.5A discharge. 4 of these in the unit that Lightfoot98 put me on to would work VERY well, especially when you consider that each cell would be drained at less than 0.5A (one big advantage of 4 in parallel).

These days everyone is either using a smart phone or looking at getting one. Things like being able to snap a photo and then upload it directing into Facebook or Google+ as well as all the other cool feature makes them a 'must have' item of the modern day. Being able to charge your smart phone while camping in the woods or sitting in a bus or train or whatever - that's just brilliant! Actually my inside jacket pocket is large enough to fit a charging box + cable + cell phone which means I can charge my phone in my pocket while riding a motorcycle - pretty cool, huh!
 
Glad you enjoy it.

I really like them, that is why I put up the link, I figured other people might like them.
Yea, pulling less than 500ma, you get max out of the cells.
Most 18650's are rated at 500ma draw for max capacity,
so this thing is gentle on the cells.


I have 3 myself, plus 1 that has the 2S/2P configuration.


Mine arrived in 7 days also.
Quick shipping.
 
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I built one from a Mintyboost kit in a portable 18650 charger, see this thread for links. Tested with iPhone 3Gs.

Thanks to Viper715 for the original tip.

HM486.jpg
 
Just be aware that for newer iPods, iPhones and iPads you'll need voltage on the USB data lines to avoid "Unsupported Charging Accessory". The voltage on each line affects the charge rate. More info.
 
Rando said:
Just be aware that for newer iPods, iPhones and iPads you'll need voltage on the USB data lines to avoid "Unsupported Charging Accessory". The voltage on each line affects the charge rate. More info.
Click to expand...

Just add that to the dozens of reasons that I wont buy anything made by Apple. Even my HTC Android phone is no longer running the HTC supplied OS, I've switched to Cyanogen Mod 7.
 
psychbeat said:
hopefully get a full charge off of an NCR 2900:sssh:
Click to expand...

I would certainly think so! From what I can figure the Apple iPhone battery is ~1200mAh, similar to my HTC Desire HD battery and I've read reports that a 2400mAh 18650 can fully charge a dead 1200mAh battery using the charger that you are looking at.

If you have 4 of 18650 batteries that are fully charged then you would only need one of those to fully charge your dead iPhone, so you would still have 3 spare 18650 cells. You could fully charge the dead iPhone twice and still have 2 spare cells for your lights.
 
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