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        Question Charge cell phone batteries with balance charger?

#1 TheSelf Oct 29, 2012 08:10 PM

Charge cell phone batteries with balance charger?
 
Hi all

I have a turnigy accucell-6 balance charger:

http://www.hobbyking.com/hobbyking/s...idProduct=7028

I'm trying to figure if it's possible to charge my cellphone Li-ion batteries externally with this charger...Can anyone tell me if this is possible?

If so- how would anyone suggest physically connecting the battery charger to my big new Samsung galaxy note 2 3100 mAh spare Lithium ion battery? The terminals are tiny ( see picture of the battery here: http://www.clove.co.uk/product-image...-sam-n2bat.jpg- in the picture you can see there are 3 terminals- the 'positive' and 'negative' terminals are marked- what's the middle one? It would be great if there is a way to connect/ charge my spare batteries and not have to purchase an external cell phone battery charger that only charges at 0.5A when I could charge at 3.1A with this... Am I right in thinking these batteries are all '1cells'/1S'? - on the back it says"3.8V Li-ion" - I take it that means a 1S ( so no balancing required)- the accucel charger is supposed to charge Li-ion batteries but what setting is 3.8V? - that appears as 0.1V higher than even 'Lipos.'.?

Grateful for any feedback.

Thanks in advance!

#2 rampman Oct 29, 2012 10:29 PM

Careful. That cell may have a circuit inside rated at less than an amp.
I did this last week for a cuz that left charger at home but at
4 amp to be safe.
To connect I used black electrical tape and put a ball of solder on the end of wires but it can be an intermittent connection and IMO not worth it if you have a charger.

#3 TheSelf Oct 29, 2012 11:46 PM

Quote:

Originally Posted by rampman (Post 23135208)
Careful. That cell may have a circuit inside rated at less than an amp.
I did this last week for a cuz that left charger at home but at
4 amp to be safe.
To connect I used black electrical tape and put a ball of solder on the end of wires but it can be an intermittent connection and IMO not worth it if you have a charger.

Thanks for your reply- just to confirm we are on the 'same page'- I'm talking about charging the battery externally- ie. outside of the phone- not charging with the battery inside the cell phone- so the circuit of the cell phone I guess isn't important- what wiring/cable did you use to connect your balance charger to the cell battery directly?

Thank you

#4 ttabbal Oct 30, 2012 12:02 AM

If you peel the sticker off, you will find a bare cell with a little pcb where those terminals are. It will likely limit your charge and discharge rate to about 1A, maybe a little more. The note might be higher, whatever the charger it comes with will be close to the cut off. I tried it on a galaxy nexus battery. If you connect directly to the cell, you can go faster. But on the exposed terminals, that little pcb will cut the cell out of the circuit if you try to go too fast.

#5 mrforsyth Oct 30, 2012 12:28 AM

IMO, spend four bucks and save yourself a LOT of potential grief...

http://www.ebay.com/itm/Desktop-Dock...item4abd0ad7b3

http://www.ebay.com/itm/New-Stand-Do...item2323f21b9a

Mark

#6 Julez Oct 30, 2012 06:47 AM

I have done this a couple of times, and there is no problem. Set the charger to less than an amp. The contact in the middle is just a temperature sensor, no need to connect it.

The only problem might be a suitable interface between the battery and your charge cable.
I suggest getting a piece of wood, hammer in 2 nails so that the backside of the battery has something it can rest at, and put two appropriately shaped pieces of music wire at the front, which press themselves on the contacts. Solder your charge cable to these wires.

I have stopped tinkering though, and got a charger with multiple bays for all my non-RC stuff.
http://www.digibuddy.eu/

#7 TheSelf Oct 30, 2012 01:34 PM

Thank you- but I already loked at these options- but these only charge at 0.5A or less- will take 10-12 hours to charge- I wanted to try charging with my balance charger to get at least 1Amp or more charging...

Quote:

Originally Posted by mrforsyth (Post 23135785)
IMO, spend four bucks and save yourself a LOT of potential grief...

http://www.ebay.com/itm/Desktop-Dock...item4abd0ad7b3

http://www.ebay.com/itm/New-Stand-Do...item2323f21b9a

Mark


#8 ttabbal Oct 30, 2012 02:02 PM

Quote:

Originally Posted by TheSelf (Post 23139668)
Thank you- but I already loked at these options- but these only charge at 0.5A or less- will take 10-12 hours to charge- I wanted to try charging with my balance charger to get at least 1Amp or more charging...

One thing I did when I was experimenting was take apart a cheap charger and use its contacts for the battery connection. Makes connecting easy. Then used alligator clip leads from the charger. As mentioned, don't expect more than 1A or so, unless the phone can charge faster. For example, the Kindle Fire can do 2.5A. So if its battery were removable, you could probably use that as a max charge rate without tripping the protection circuit.

#9 mrforsyth Oct 30, 2012 02:05 PM

You can always modify them with switch and a second set of leads to go to your hobby charger for those times when you're in a hurry. Much simpler, cleaner, and more reliable than a homebrew adapter.

The second one that I linked will charge at up to the current that is provided by the attached USB cable. I have some USB chargers that will provide > 2 amps. These are not hard to find.

Mark

#10 TheSelf Oct 30, 2012 03:09 PM

Quote:

Originally Posted by mrforsyth (Post 23139897)
You can always modify them with switch and a second set of leads to go to your hobby charger for those times when you're in a hurry. Much simpler, cleaner, and more reliable than a homebrew adapter.

The second one that I linked will charge at up to the current that is provided by the attached USB cable. I have some USB chargers that will provide > 2 amps. These are not hard to find.

Mark

I was confused by the tem 'USB charger' - thinking that mean specifically that it charges at a standard reduced 0.5A rate (my samsung phone has a basic charging status showing when charging of 'USB' (which is reduced or 'AC' which is 2A- my samsung galaxy note 2 charger that plugs into my AC wall outlet and has a detachable USB cable that connects to the phone- charges at 2A- so you are saying these 'USB chargers' don't only charge at a reduced rate- in this instance with the second product you listedI can connect my samsung charger to this device & I could charge a spare battery outside the phone at 2A?- if so- this is a great find - thank you!

#11 TheSelf Oct 30, 2012 03:16 PM

Quote:

Originally Posted by ttabbal (Post 23139877)
One thing I did when I was experimenting was take apart a cheap charger and use its contacts for the battery connection. Makes connecting easy. Then used alligator clip leads from the charger. As mentioned, don't expect more than 1A or so, unless the phone can charge faster. For example, the Kindle Fire can do 2.5A. So if its battery were removable, you could probably use that as a max charge rate without tripping the protection circuit.

my phone (Samsung Galaxy Note 2 can charge at 2A- with its included AC wall outlet charger, with the phone plugged in- I would think that charging the battery externally with my RC balance charger- if a 3100mAh capacity- I could charge at at least 3.1A (1C)..is this incorrect?

#12 TheSelf Oct 30, 2012 03:17 PM

Quote:

Originally Posted by Julez (Post 23136792)
I have done this a couple of times, and there is no problem. Set the charger to less than an amp. The contact in the middle is just a temperature sensor, no need to connect it.

The only problem might be a suitable interface between the battery and your charge cable.
I suggest getting a piece of wood, hammer in 2 nails so that the backside of the battery has something it can rest at, and put two appropriately shaped pieces of music wire at the front, which press themselves on the contacts. Solder your charge cable to these wires.

I have stopped tinkering though, and got a charger with multiple bays for all my non-RC stuff.
http://www.digibuddy.eu/

thanks for the tips!

#13 alejoc Mar 09, 2013 02:51 PM

Hi, I would like to know if these chargers can estimate a cell phone Li-ion battery's capacity when connected. I am planning to use the iCharger as a battery tester-analyzer for cell phone and camera batteries.

#14 mrforsyth Mar 09, 2013 03:01 PM

Most chargers with discharge capability can assess battery capacity. Simply fully charge the battery and then discharge it at the load that the battery sees in its native device and note discharged capacity on the charger display.

Welcome to RCGroups!! :)

Mark

#15 alejoc Mar 09, 2013 04:18 PM

Thanks for the quick reply and the welcome. The thing is, a cell phone's consumption is quite variable, so I wonder if I need some kind of load bank in order to discharge the batteries?


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