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-   -   Li-Ion 3.6V Button Cells! AWWW YEA!!! (http://tinyrc.com/forums/showthread.php?t=3004)

ax0n 11-06-2002 06:04 PM

Li-Ion 3.6V Button Cells! AWWW YEA!!!
 
I need to break out the ZZ tonight and see if these bad boys work, but first I need to charge them up. I'll scan the info soon enough and post some results. I'm pretty stoked about leaching 3.6V from one single cell.

I got 2 samples:

2450 Form Factor:
24.5mm Diameter x 5.4 MM height
90 mAH
3.6V
Max Continuous drain: 32 mA :(
Charge Condition: 4.2v 26mA
Max Pulse discharge: 90mA
Weight: 5.2g (Kinda heavy)
500 Charge/Discharge cycles
Self Discharge Rate: 10% Per month (not bad for a Li+ Cell)


2477 Form Factor:
24.5mm x 8.4 mm
130 mAH
3.6V
Max Continuous drain: 52 mA (that may suck)
Charge Condition: 4.2v 26mA
Max Pulse discharge: 275mA (Wheee!)
Weight: 7.8g (not bad considering this thing's dimensions!)
500 Charge/Discharge cycles
Self Discharge Rate: 10% Per month (not bad for a Li+ Cell)

PT Bruiser 11-06-2002 07:49 PM

cool!!!
 
Yeah,

Please let us know how these work out! I believe some time ago, Mattydiah was talking about trying these, but in that thread, I believe it was discussed that whatever charger you used for these things had to be verrrry precise. A bit under, and you screw the life of the battery, and a bit over, and you fry it. Thanks for the details so far, but let us know about the charger you used too, besides telling us how your ZZ hauls ass!

Keep Cruisin'

PT Bruiser

Mattydiah 11-06-2002 09:24 PM

Yeah, I tried to order some of these free samples, but they just keep asking me (in super broken english) what I'll be using them for. After telling them about 5 times, I just gave up. :mad:

Yeah, if you're gonna be charging these batteries, be very sure that you are getting constant voltage, or the batteries will be botched.

ax0n 11-06-2002 11:29 PM

I'm very familiar with charging of Li+ Cells. I need to make a run to some new electronic parts supply stores soon, because I need some components that RS just doesn't carry anymore. :(

One thing I've been looking at is some of the pin-package power supply/battery charger chips that Linear offers. I found a pretty nifty Li-ion charger schematic in one of my electronics tech ref books that uses Linear Technologies LT 1511 chip, but I think something like the LTC1731 would work better for my application.

Here's a handy link:

http://www.linear.com/pdf/ltc0900.pdf

I'll post some more good stuff here in a bit.

ax0n 11-06-2002 11:50 PM

Clicky teh thumbnails for a REALLY FRICKIN HUGE version. ;)

Charger Schematic I found:
.http://buddha.jccc.net/~axon/batt/tn_skem.gif.

LIR2450 Datasheet (Actual LIR2450 battery in the scan)
.http://buddha.jccc.net/~axon/batt/tn_2450.gif.

LIR2477 Datasheet (Actual LIR2477 battery in the scan)
.http://buddha.jccc.net/~axon/batt/tn_2477.gif.

Able Battery: Lithium Ion Button cell, page out of their catalog
.http://buddha.jccc.net/~axon/batt/tn_able-button.jpg.

GTR 11-07-2002 01:58 AM

where can i get these samples?

ax0n 11-07-2002 03:11 AM

getting the samples seems to be a pain in the butt. Even I myself had to bullcrap a little to get them to send them out. Rightfully so, actually. you need a license in the U.S. to handle raw Lithium Ion cells for commercial use, and they are strictly forbidden for use by the casual consumer.

Lithium ion cells are terribly volatile and will explode violently if mishandled, overheated, shorted out, or charged improperly. They do not support venting valves like those found on NiMH and NiCD cells. They are capable of taking a hand off if they blow.

IF I can make this work the way I want it to, I may be importing batteries and hand-building specialized lithium ion chargers for sale. I'll also provide schematics for the final charger that I build should these batteries hold any promise. If I can find anything that works, I'll also try to purchase a battery bracket holder for these batteries in bulk, so that I can offer them at a discount. Trust me, you do NOT want to solder anything directly to these cells. it would be very ugly.

Should you decide you can figure out a way to deal with them, it's a chinese company that Axel found (I think) online called Able Battery. www.Able-Battery.com. Don't tell them that a bunch of people want to put these in little R/C cars, they'll probably find us and stop dealing with any of us, myself included.

I had to use my work e-mail ad mailing address, my work phone number, some creativity, and my full set of "social engineering" skills to get them to send me samples of their lithium ion offerings.

lnx_author 11-07-2002 07:34 AM

Quote:

Originally posted by ax0n
Lithium ion cells are terribly volatile and will explode violently if mishandled, overheated, shorted out, or charged improperly. They do not support venting valves like those found on NiMH and NiCD cells. They are capable of taking a hand off if they blow.
...
I can find anything that works, I'll also try to purchase a battery bracket...

- yea! a hobby item that can blow your hand off! (this reminds me of my gas-powered mini-car days, when we would drag-race cars - the little ones with two holes in the bottom carriage using a long string as a guide)

- i'm looking for a good source on the button brackets! got a good link/vendor?

tia!

ax0n 11-07-2002 01:19 PM

For button cell holders I'm just gonna try KC Electronic Supply down the highway a bit. they sell whole boxes of stuff at a pretty heavy discount if you're in good with them. I also need to see if they carry anything from Linear Tech. If they do, I'll just buy the LIon charger parts from them too.

The batteries are small enough that they may very well fit on top of the chassis and inside the bodies. If that's the case, I'll probably design the charger so that you physically remove the button cell from the car and put it on the charger, then put it back in the car. I don't want the car's circuitry causing any fluctuation in the voltage or amperage. Lithium ion requires an EXTREMELY stable power source.

MicroRCracer 11-07-2002 02:34 PM

cool battery idea!! great job!!

Mattydiah 11-07-2002 04:17 PM

Ables site seems to be down now. Has anyone been there in the last few days?? Does it still exist?

dcp 11-19-2002 07:17 PM

Have not seen an update on this??? Did the axON blow himself up.

axON if you still have all your fingers and can still type I am curious as how this turned out.

ax0n 11-20-2002 12:00 AM

No, I just haven't built a charger yet, and my ZZ is messed up. I need to just go buy a new one sometime. On top of that I have a ton of bills and it doesn't look like this is going to be a very happy holiday season. :(

Too much stuff to do and too many bills to pay, hopefully my schedule clears up a bit and I make some dough so I can start tinkering again.

dcp 11-20-2002 12:30 PM

:( I know how you feel there. I've got to give the wife a Purchase Order just to try to get new batteries.:D


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