Replacing 3S LR44 button cells with li-ion?

Is it possible to use 10180 li-ion cell in a device designed for 3 X LR44 / AG13 in series?

The size is almost the same and voltage too. Opinions?

Re: Replacing LR44 button cells wit li-ion?

If I had a 10180 I'd try it given the value of the only device i have that takes three LR/SR44 cells.

I'd like to know too.

10180? gee, I never thought of that:laughing:
I'm interested to know too

Wikipedia states LR44 maximum height as 5,4mm. 5,4x3=16,2mm. 10180 is 18mm. I think it might fit some devices with a loose spring but not ones with a tighter fitting.

Has anyone tried this yet? I just might order 10180 and a nano charger to try out

Internal resistance of the 10180 might be too low, resulting in whatever it is using too much current and breaking. Be interesting to hear the results, though

santza said:

Wikipedia states LR44 maximum height as 5,4mm. 5,4x3=16,2mm. 10180 is 18mm. I think it might fit some devices with a loose spring but not ones with a tighter fitting.

Has anyone tried this yet? I just might order 10180 and a nano charger to try out

Click to expand...

You get the cell, I'll contribute the Nano (I have more than one) - PM me with your address.

I'd be a bit concerned that the Nano charging current is rather too high for such a small cell. But then Rob sells them with the Wee lights so presumably he reckons it is safe to charge them in a Nano.

dulridge said:

You get the cell, I'll contribute the Nano (I have more than one) - PM me with your address.

I'd be a bit concerned that the Nano charging current is rather too high for such a small cell. But then Rob sells them with the Wee lights so presumably he reckons it is safe to charge them in a Nano.

Click to expand...

PM sent!

santza said:

PM sent!

Click to expand...

Packed up - will post it in the morning

IT WORKS!!

:rock::rock::rock::rock:

Good get!

You know you've only gone and made heretofore junk lights suddenly practical...

I've wanted to try this with my HP 32SII calculator but I'm a bit worried about over-voltage in such a valuable piece of gear. Been meaning to take an adjustable power supply and gradually ramp it up to see if it can handle the voltage that the lithium cell puts out.

The question is, what is the current draw on the li-ion vs the 3 LR44s?

Re: Replacing 3x LR44 button cells with Li-ion?

santza said:

The size is almost the same and voltage too.

Click to expand...

But as Jarl mentioned, the internal resistance will be much MUCH lower. In some devices it might be fine, while others might go

Illum_the_nation said:

If I understand your concern consider that LR44s capacity resides between 150-200mah depending on alkaline or silver-oxide the current draw at the most would still be within the safe level of the 10180...unless of course the capacity of the 10180 is below that of LR44s which I find very unlikely

Click to expand...

:huh2: The capacity has nothing to do with the internal resistance. You could use four LR44s and still have less voltage under load than the 10180. Indeed, my latest keyring torch relies on the internal resistance of LR44 cells to limit maximum current.

What I want to know is does the lower resistance of the li-ion mean more current than the button cells w/ voltage sag under load.

I measured capacitity of AW 10180 liIon with a hobby charger at discharge current of 0.1 amp = it was only 65mah

3XLR44 is around 120mAh at 4,5v
3XSR44 is around 180mAh at 4,65v

so do not discharge more than 130mA!

Is the math done correct?