Putting 18650's in CR123 x2 only lights

[PayBack]

Hi ppl...


I like the form factor of the Olight SR50 much more than that of the M31, but it only takes CR123's (or I believe RCR's at much reduced runtime) where as the M31 can use 18650's, making it much cheaper to run.

My question is, what would happen if I put 3x 18650's (assuming they fit) in an SR50? I'm guessing it would be bad, but am curious anyway.

Also I thought there's rechargeable batter = to 2 x CR123?

 

[Lighthouse one]

In some cases the 18650 is too large in diameter. It's 18mm vs 16mm for the 123.
THe 18650 runs around 4.0 volts under load. 2 123 around 6.
You'll have to wait for someone who has the light to chime in...but in many cases the 18650 can replace the 2 123 batt if the driver will run ok at the voltage.

 

[PayBack]

Ok so it doesn't sound like it will go BANG!

 

[aEx155]

My question is, what would happen if I put 3x 18650's (assuming they fit) in an SR50? I'm guessing it would be bad, but am curious anyway.

3x18650 = 4v*3 = 12 volts = bad idea

1x18650 = 4v < 6v = no explosions

I did have a driver fail on my by running it on half the voltage it was made for, though.

 

[goki]

A quote from the website:

Battery: 6 x CR123A batteries or RCR123A( Runtime will reduce)

For CR123A, that's 6 x 3v = 18v. If you use RCR123A's, 6 x 4v = 24v.

Looks like a no go for me. 3 x 18650's = 12v.

 

[PerttiK]

Do we know that the batteries are in series?
If they are and this light uses a buck circuit then 3x18650 should work assuming they fit?

 

[goki]

Do we know that the batteries are in series?
If they are and this light uses a buck circuit then 3x18650 should work assuming they fit?

Ah, yes. I forgot about the other types of battery configuration.

I saw a picture of the SR50's battery carrier and it looks like a bank of battery (2 x CR123A/RCR123A) is definitely in series.

Deducing from that, possible configurations are:
- all batteries in series config = 18-24v
- 2s3p config (2 in series, 3 banks in parallel) = 6-8v

Chances are, its using a 2s3p setup.
Either of those two configuration requires a bit more voltage that 3x18650's cannot provide though.

 

[jorn]

edit. wrong m31

 

[PayBack]

So there's no recharable battery the same output, size and shape as 2x CR123?

Surely they'd sell well to ppl like me!