Li-Ion 17670 Source ????

Ben H · Jul 18, 2003

I am looking for a source to buy Li-Ion 17670's. The dimensions of the 17670 are the same as two 123 cells. Does anybody have a source for these cells?

I'd like to use these in my L4. At what voltage does the L4 drop out of regulation? If it is around 2.5 - 3V then maybe it is safe to use these cells without a cell protection circuit.

I'm looking for input and suggestions. I know I could go out and buy the Pila cells, but I'm trying to have some fun and maybe find some cheaper Li-Ion cells. The Pila 168S goes for $31!

Doug S · Jul 18, 2003

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Ben H said:
I am looking for a source to buy Li-Ion 17670's. The dimensions of the 17670 are the same as two 123 cells. Does anybody have a source for these cells?

I'd like to use these in my L4. At what voltage does the L4 drop out of regulation? If it is around 2.5 - 3V then maybe it is safe to use these cells without a cell protection circuit.

I'm looking for input and suggestions. I know I could go out and buy the Pila cells, but I'm trying to have some fun and maybe find some cheaper Li-Ion cells. The Pila 168S goes for $31!

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Ben, here is a source. At 1500mAhr, these are the highest capacity 17670 cells that I am aware of. This source is in the far East so if ordering just 1 or 2 shipping is a bit onerous. Larger orders it aren't too bad with the same shipping $ spread among more cells.
Naked Li-ion cell source
Sorry, I have no info on the input charactistics of the L4.

Ben H · Jul 18, 2003

Doug,

Thanks for the website. That's the first place I've found on the web that sell 17670's.

Doug S · Jul 18, 2003

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Ben H said:
Doug,

Thanks for the website. That's the first place I've found on the web that sell 17670's.

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Ben, you are welcome. If you decide to go forward with this, email me. Maybe I could tag along on your order for one or two.

Ben H · Jul 18, 2003

Doug, do you have any thoughts about using these without a protection circuit? I just got my L4 and haven't been able figure out at what Voltage it drops out of regulation. I'm also need to gather more info on charging these things. Lenmar makes some great Li-Ion battery chargers that would probably charge on of these 1500 mAh cells in less than an hour, but I don't want to blow my house up!! Once I firgure out a good way to charge these and if it is practical to use them in the L4, I may order some. You are welcome to tag along. You had me thinking the shipping would be way expensive! $12 isn't too bad.

Doug S · Jul 18, 2003

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Ben H said:
Doug, do you have any thoughts about using these without a protection circuit? I just got my L4 and haven't been able figure out at what Voltage it drops out of regulation.

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Not knowing anything about the L4 electronics I cannot help you there. BTW, the relevant voltage for the circuit would not be when it drops out of regulation but instead, the voltage below which it draws negligible current. For simple resistive current limiting or *some* designs of linear constant current regulators, Li-ion cells do fine without protection for driving white leds.
If you are handy with electronics, it is not hard to build your own charger. Limit charging voltage to 4.20V [I recommend 4.15V, especially if you don't use a charge timer] and charging current to below C rate[I usually use <0.5C]. A simple LM317 based circuit works fine.