18650 Cell Phone Charger

[HooNz]

So whats the go with the mathematics of these chargers , they look like the bee's knee's :-)

If the battery to be charged is 850mah (a BL5C) 3.7v , and one has 2x18650 at 2400mha each in parallel? which is 4800mha total and a converter efficiency of maybe 80%? (a guess) and a recharge of 110% or 120% or so does that mean around 3 recharges? , its confusing for me so anyone with practical experience like to say , TIA.

Also , those 2x AA types , are they any-good , as in the way they work , i am aware that there is probably only one recharge , but out from mains power or a extended mains power out and since AA's are everywhere or one might have a box full of lets say Lithiums for example , i might actually like those types , any thoughts or experience also please .
http://www.ebay.com.au/itm/Black-Eme...item27c4f2404b

This thread has been a good read imo

[KiwiMark]

So whats the go with the mathematics of these chargers , they look like the bee's knee's :-)

If the battery to be charged is 850mah (a BL5C) 3.7v , and one has 2x18650 at 2400mha each in parallel? which is 4800mha total and a converter efficiency of maybe 80%? (a guess) and a recharge of 110% or 120% or so does that mean around 3 recharges? , its confusing for me so anyone with practical experience like to say , TIA.

Also , those 2x AA types , are they any-good , as in the way they work , i am aware that there is probably only one recharge , but out from mains power or a extended mains power out and since AA's are everywhere or one might have a box full of lets say Lithiums for example , i might actually like those types , any thoughts or experience also please .
http://www.ebay.com.au/itm/Black-Eme...item27c4f2404b

This thread has been a good read imo

I have a 2 x AA charger (made by Sony) and it is good for ~ 1/2 a charge. That cheapo one may not be as good.
With a 4 x 18650 charger I can keep my cell phone charged for about a week away from power with heavy use as a book reader.

[HooNz]

I have a 2 x AA charger (made by Sony) and it is good for ~ 1/2 a charge. That cheapo one may not be as good.
With a 4 x 18650 charger I can keep my cell phone charged for about a week away from power with heavy use as a book reader.

Thanks a heap for the info , but may i ask what size is the cell phone battery for the half a charge scenario , and also what size AA's , Lithium AA's are supposedly well over 2000mah , the 4x18650 might be the go for longer times from mains power it that is on just one charged set of 18650's? correct , cheers...

[psychbeat]

The single 18650. + USB flashlight iPhone/phone charger I got on eBay a while ago is still going strong. Get atleast a full charge on it w 3100mah Panasonic.
Only charges the cell up to ~4v tho when reverse charging.

[KiwiMark]

Thanks a heap for the info , but may i ask what size is the cell phone battery for the half a charge scenario , and also what size AA's , Lithium AA's are supposedly well over 2000mah , the 4x18650 might be the go for longer times from mains power it that is on just one charged set of 18650's? correct , cheers...

It was whatever came with my Nokia N95. The efficiency isn't so good when the voltage needs to be stepped up.

The one I like is my 2s2p charger running from 4 x 18650 because the voltage doesn't need to be stepped up.

4 x 2400mAh x 3.7V = a hell of a lot more stored power than 2 x 1.2V x 2000mAh.
i.e. 35.52Wh vs 4.8Wh = 7x as much power.
Then factor in the lower efficiency when you need to step 2.4v up to 4.2V compared to reducing 7.4 V to 4.2V.
Also consider that the 2400mAh cells are the good value for money option, you can go with 3100mAh cells if you don't mind paying more and that would give you 4 x 3100mAh x 3.7v = 45.88Wh (9x what 2 x AA will provide) of power!

[alex21]

How reliable is the voltage cut off with these chargers?
I think the flames I bought from DX may have been fakes.
Maybe I'll try the Sanyo 2400mah unprotected for around $6 or the new flames "3000mah".. seems to provide solid 2400-2500mah for $11.7/pair
More to the fact, maybe I should think about upgrading my iPhone 3G (yep the 2008 one), battery seems flaky..

[Naguz]

Great, the bloody useless crap forum refused to post my post because I had logged in since i loaded the previous page (wtf I had not!) and ate my post. Great.

So instead of a in-depth post, I'll just reply that the charge cutoff on this unit which I've bought measures 4.19V for all four cells.

I harvested the batteries from an old laptop battery pack, matched them (ie. sorted out two that self discharged a bit mor than the others) and bought on of these to have power on an oncoming 17hr flight. It will also be great for my ereader when I'm in a cabin without electricity for several days.

I'll strip a USB cable so I can measure the volt it puts out.

I'm not sure I'll be able to test the cutoff discharge voltage atm, I don't know where I'd put the current. :P

Update: it puts out 4.91V when I connect it to my phone with a VERY flimsy usb cable that I also managed to damage while stripping, as I couldn't be bothered to use anything but the knife I had handy. The second I turned the charger on it spiked at 5.2V for a fratcion of a second. While this is ell within tolerance, it might have been higher - it isn't exactly a high quality ripple measurer I've got. The phone (S II) also saw it as AC power.

If it lasts, it seems I have got myself a very cheap and well working external battery pack!

[Changchung]

I just receive a 3A 4P 18650 power box, it just charge my Iphone from 54% of battery to 100% in last than one hour, I am going to used very well, almost all days and charge the batteries in the same box with a old PS PC using the 5V output, I hope It last long...



SFMI4UT

[Norm]

Great, the bloody useless crap forum refused to post my post because I had logged in since i loaded the previous page (wtf I had not!) and ate my post. Great.

Sounds like you don't have the "remember me" box ticked on the log in page, not really the fault of the forum.

PS Please moderate your language, this is a family friendly forum.

Norm

[HooNz]

@ Naquz A trick i have learned is before you click post , highlight/right click the words and copy , i dunno how may times i did a long post and it disappeared when there was a "issue" .

Your link just comes up with the login page , is it supposed to? i wanna look at the gadget .

@ KiwiMark , your battery is 950mah if it is the standard one , thanks...

R/CLICKED AND COPIED

[HooNz]

After spending quite a lot of time looking i dunno which I'll choose in the end , the XTAR WP2 II looks good too! , but i gotta wait for next week as i might be getting hold of a fairly good shortwave receiver for a good price , gotta wait

[Norm]

HooNz Aldi where selling a nice 7400mAh general purpose USB out recharge pack for $30 about 3 or 4 months ago, really finding mine very useful.
Keep you eye on Aldi they have some unexpected items at times.

Looks very much like the pack apple selling for about $90 but the Aldi pack is about twice the capacity.

Norm

[Naguz]

@ Naquz A trick i have learned is before you click post , highlight/right click the words and copy , i dunno how may times i did a long post and it disappeared when there was a "issue" .

Your link just comes up with the login page , is it supposed to? i wanna look at the gadget .

I know, I used to do that, but the forum claims it auo-saves my posts nw, so I got lazy.

Anyway, this link should work.

The biggest minus with it is that it seems to be a booster circuit that can run on just one cell. That might be a big plus to some, but it probably means lower efficiency, and makes me somewhat uneasy about the charging feature if you used batteries different selfdischarge frequiencies etc. I'm not really sure hw it measures voltage, or if it has any more than one charging channel.

[Norm]

That might be a big plus to some, but it probably means lower efficiency, and makes me somewhat uneasy about the charging feature if you used batteries different selfdischarge frequiencies etc. I'm not really sure hw it measures voltage, or if it has any more than one charging channel.

It appears all the cells are in parallel. Li-ion charge OK in parallel.

Norm

[Norm]

That might be a big plus to some, but it probably means lower efficiency, and makes me somewhat uneasy about the charging feature if you used batteries different selfdischarge frequiencies etc. I'm not really sure hw it measures voltage, or if it has any more than one charging channel.

Looking at the pictures the cells are in parallel. Li-ions charge OK in parallel.

Norm

[HooNz]

HooNz Aldi where selling a nice 4000mAh general purpose USB out recharge pack for $30 about 3 or 4 months ago, really finding mine very useful.
Keep you eye on Aldi they have some unexpected items at times.

Looks very much like the pack apple selling for about $90 but the Aldi pack is about twice the capacity.

Norm

Now there was a place i would not have thought of Norm , thanks .
Just been on the site but could not find any BUT did you see the 4 stroke Generator @2200w , regulated and below 300 buckeroonies
Next time I'm going past i'll have to drop-in to look to see what they got

[HooNz]

I know, I used to do that, but the forum claims it auo-saves my posts nw, so I got lazy.

Anyway, this link should work.

The biggest minus with it is that it seems to be a booster circuit that can run on just one cell. That might be a big plus to some, but it probably means lower efficiency, and makes me somewhat uneasy about the charging feature if you used batteries different selfdischarge frequiencies etc. I'm not really sure hw it measures voltage, or if it has any more than one charging channel.

Thanks , as Norm mentions , looks like all in parallel going by the red wire in one picture but the other end might be in pairs?, so it will run just with one battery , or 2 or ? , one could easily work out the converter efficiency , use a known load resistor on the usb outlet , say for 1/2 a amp at 5v(or 250ma) then just measure the battery current with a multimeter , then ohms law % with a calculator , thats fairly basic but those others have got me stumped a few posts back (to many for me) , cheers

[Norm]

This is the one.

Another info link.

Norm

[HooNz]

This is the one.

Another info link.

Norm

Thanks Norm, looks good aye! , I'll go and pester them if i remember .

[Naguz]

Looking at the pictures the cells are in parallel. Li-ions charge OK in parallel.

D'oh. That was pretty much a given, given that it has a booster curcuit, as I mentioned in the same post - think I'll have to stop posting about battery stuff during lectures. xD

I'll probably not measure the real capacity, HooNz, but considering it can contain 4x2600mah 18650s it would put out 8320mah(@3.7V)/39,4Wh even if it just have an 80% efficiency. That is ~7870mah@5v. Concidering my cellphone battery is (from memory) 1550mah@3.7V, aka 5,73 Wh. This means it should charge my phone nearly seven times. But of course, with the efficiency loss in the phones charging circuitry, this will not happen.

Some posts here in this thread suggest an efficiency of 70% all the way from 18650 cell to phone battery with these 1S units. That isn't too bad, considering my unit supposedly cut off at 2.9V Many of the higher capacity 18650s has a suggested cutoff voltage at 2.7 or even 2.5 - this means the total efficiency should be well above 70%, including the inefficiencies in the phone circuitry.

It surely beats the 2xAA ones out there that barely psuhes my phones 1550mah battery to 35%...

[HooNz]

Hey look at this one http://www.ebay.com.au/itm/USB-Mobil...item3cbc6ec31e

The 18650's are in series parallel in other words a 8v input , so a step down 8v-5v charger ...

[Changchung]

Mine just dead... I used two times... Emailing the seller and working to resolved...

I think that this cap just blow. See the center of the pic.http://img.tapatalk.com/be79ef9e-4e53-83e6.jpg


Your images are too large and have been replaced with links
See Rule #3 If you post an image in your post, please downsize the image to no larger than 800 x 800 pixels. - Norm


SFMI4UT

[HooNz]

Yes looks like hole in it

[Changchung]

Hi, from the begin was a bad experience, I buy one from china, the 3amp model with 4p batteries, I was forced to open a claim in paypal for item not recieved, almost two months later I received two of the same power boxes but in differents packages, I think that the seller send me a extra for gift, I dont know, well, one is working great, the second one when I try to test a pair of caps inside just exploid, those are for filtering the DC output, I replace it and exploid again, I am not using that one trying to find out what this happen...

This kind of gadget are a lotery..


SFMI4UT

[mohanjude]

I do like the idea but not sure if I trust it to charge my Ipad....

[Changchung]

I am using the good one to charge my iphone, with 4 2200 charge it very fast.

Remember that you have to use unprotected 18650


SFMI4UT

[Changchung]

Hi guys, I just want to update my experience with those, the seller send another that is working just fine. I put 4 2400 lg batteries in and I charge my iphone like ten times without charge the batteries yet. So, I think that is a lottery receive a good box of this from china. Any way, for 13$ I can give it the shoot...


SFMI4UT

[Norm]

How about a flashlight that doubles as a USB charger?



Google this description

Features:

*Material: 6030 Aircraft Aluminum

*Bulb: 1 x CREE XM-L T6 1A LED

*Reflector: SMO Aluminum

*Brightness: 800 lumens

*Power supply( NOT included ): 3 x 18650 (Parallel)

*Modes:

High-Medium-Low-Strobe-SOS

High-Medium-Low

*Switch: Tail cap reverse switch

*Constant current (8*AMC7135)

*Finish: Hard Anodize II

*Dimension( mm ): 155( length ) x 46(body) x 46( head )

*Weight: 271grams (without batteries)



Special Functions:

*Two USB outputs, can simultaneous charge two devices

*The left USB Output (Apple) can be used only for Apple (Iphone, Ipad) and HTC products.

*Charging ICs: LTC1700, MAX1879

*On/Off button for Output

*Output current: 300-2500mA, automatic adaptation

*Over-discharge protection when the battery voltage is 3V (first 4 LEDs will be off)

*Charger built in for 3*18650 batteries

*Charging takes approximately 8 hours for 3*18650

*When the batteries are almost full, the 4 red LEDs will flash, when the batteries are full the 4 red LEDs will turn to blue and stop charging.

Norm

[Changchung]

I like this option. Checking right now...


SFMI4UT

[PapaLumen]

The "apple" usb should be able to be used by anything that can accept a 1A usb input, the other is standard usb 0.5A.

Search for: DOUBLE USB MOBILE DEVICE CHARGER 3*18650 XM-L T6 FLASHLIGHT