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Dec 08, 2002, 10:11 AM
Senior Member
Paul Penney's Avatar

Can Kokams be charged with ANY cell phone charger?


Hey,

I was just wondering if this was possible. I already have a charger and would like to not have to ordr in another

Paul
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Dec 08, 2002, 10:19 AM
Registered User
SoaringDragon's Avatar
I also have a 110v charger that came with my Audiovox cell phone. I bought a 12v charger but I'd like to use my 110v one, if I can.
Dec 09, 2002, 08:57 PM
Senior Member
Paul Penney's Avatar
*bump*

Surely Tres might have something to say?
Dec 09, 2002, 09:08 PM
Registered User
Peter Khor's Avatar
Probably not, most of the time, all of the charge control circuit is in the phone itself - the phone charger is a simple A/C adaptor. If it's one of those external charger that will charge a battery pack alone, it might - there will probably be a 3rd pin for the temp probe in the battery pack itself, so without that in a Kokam, the charger might not begin the charge process. Same goes with Camcoder chargers.
Dec 09, 2002, 09:11 PM
Registered User
I'd be really interested to know as well. I'm hoping to get a flight pack for Xmas with a few Kokams (145mah) and I can't afford to push out $70+ for a charger. That amount of money might be justified if the charger works with ALL current chemistries, but even then that's quite a handfull of money. Anything that would help would be highly appreciated! Thanks!

Nick R.
Dec 09, 2002, 09:14 PM
Crash Master
Gene Bond's Avatar
I figured someone else would field this one, so I skipped it...

Simple answer, NO.

Real answer, IT DEPENDS.

If the charger is designed for Lithium cells, then PROBABLY will work. Check the output voltage without anything connected (open) except the voltmeter. If the voltage is 4.0-4.2v, it MIGHT be setup for a single cell. If it's 8.0-8.4v, it MIGHT be set up for a 2 cell.

Now, connect a load of about 1 amp at rated voltage, say 4-5 ohms or 8-10 ohms, and measure the voltage and current. The voltage should sag and the current should be proportional (V/ohms). Now try half the resistance. The current shouldn't go up any more to speak of, since it should be limited to about 600-900mA, based on the intended cells.

The max current you read will tell wether you can use the charger for what size cells. The cells should not be charged at > MAH capacity... ie: 570mah cells, charge max at 570ma...

Clear?
Dec 09, 2002, 11:37 PM
Crashmaster Extraordinair
there are options with reasonable prices. I currently use the 1-3 cell charger from flyifo but it doesnt like charging partially-discharged cells.

1-3 cell, 100-1000mA charger from FlyIFO.com for $49

2 cell 200mA charger from FlyIFO.com for $24

1-2 cell ???mA charger from FlyIFO.com for $27

1 cell, 140mA charger from Bob Selman for $25

does-everything (nicad, nimh, li-ion) charger for $83
Dec 10, 2002, 12:16 AM
Former bpp dude
I stock a surplus cell phone charger that works very well on two cell packs. Output is set at 750ma. You can probably find other surplus cell phone chargers out there that will work, you have to be very careful though as if you overcharge a Kokam pack, things get ugly fast.

-Troy
Dec 10, 2002, 06:04 AM
Registered User
SoaringDragon's Avatar
That's the one I'm using now, with no problems. I'd just like to use my 110v one, so I'll take a look at the voltage & decide if I want to try using it, I guess.
Dec 10, 2002, 10:35 AM
Strange Plane Central
frankenfoamy's Avatar
I have two cell phone chargers for my cell phone. One charges the phone in on hour and the other takes 4 hours. So be aware there are differences.

Also, most current cell phone chargers are designed for one cell (4.2 volts)

The 145 mah cells would not appreciate a 750 mah charge.
Life of the cell would be affected.

A charger builder told me that these cells like a slow charge.
Fast charges fill the battery up to 80% at best and shorten thier life.

Hey Don't shoot me....I am just the messenger

http://rcguy.tripod.com/
Dec 10, 2002, 09:59 PM
Registered User
[QUOTE]Originally posted by frankenfoamy

A charger builder told me that these cells like a slow charge.
Fast charges fill the battery up to 80% at best and shorten thier life.

Please open www.fmadirect.com Click on Support, then scroll down to AN000001 to read the Applications Note for Kokam LiPoly cells. there you will find theproper information on charging and all other aspects of the liPoly cells. The cells are normally charged ay 1C. Work done recently has it appear that we can charge at 2C without harming the cells. More about that later.
Dec 11, 2002, 03:04 AM
Crazy Cessna Owner
Robbie d's Avatar
I know that the nokia phones have the charging circuit built into the phone, i recently switched from a nimh pack to li-ion and the same charger works for both