Surefire M3, drop in and battery question

A while back I grabbed an M3 with a 3 level drop in. No specs on the drop in itself but I think it's a Nailbender. Question is, should I run 2 or 3 cr123 cells? I have been using 3 but wondering what it would do with 2 and a spacer? What would the best battery configuration be? Thanks!

Don't see a D36 3 cell multi mode driver on Dave's web page? All multi mode drivers appear to be only up to 6 volts and his buck/boost drivers are all single level. Maybe is its a modded Lumens Factory D36? Mark has a few of the buck/boost (up to 18v) that are 3 level. The problem with Marks are they are not direct drop in's like Dave's are. There are some strengthening ribs around the circumference on the exterior of the reflector that hinder it from installing as received. At least that's the way they were when I last purchased one from LF. Maybe things have changed since its been years for me.

IMO a driver able to use more cells makes more sense if the driver is a constant voltage and not a constant current. But that's just my opinion. Any chance you could post a picture?

Yes, i can post up some pics in a few.

Sharpie marking.

Interesting.....? Well it certainly bears little resemblance to a Lumens Factory D36. Could easily be a CustomLites build. But you mention its a multi cell AND a 3 mode so maybe its a modded version? One thing I know for sure it's not one of my Z46 LED conversions. I use the Dereelight multi cell buck/boost driver for multi mode and my reflector has a shock foam retainer around the opening of the reflector. I don't anybody else who offers that feature. Maybe some comm's with Dave might be in order? I'm leaning towards your initial statement.

I've got a SureFire M3 that I put an LED dropin into a few years ago. I've been running it on two 18500 rechargeables. I really should look up the voltage spec to make sure I can run it on three CR123A's if I need to. I'm thinking the high end must be at least 9 volts since two RCR's fresh off the charger are about 4.2 volts each.

I remember I had to get some Delrin tool to remove the bezel from the head, it was more difficult than I had anticipated. I was reading here on CPF about M2 dropins and didn't realize that the M3's were a different head diameter.

My M3 dropin is warm white and single-mode. It may be a Nailbender, I've certainly bought from him in the past.

The light is classic SureFire from the PK era :twothumbs, it has a Z48 clicky tailcap.

m4a1usr said:

Interesting.....? Well it certainly bears little resemblance to a Lumens Factory D36. Could easily be a CustomLites build. But you mention its a multi cell AND a 3 mode so maybe its a modded version? One thing I know for sure it's not one of my Z46 LED conversions. I use the Dereelight multi cell buck/boost driver for multi mode and my reflector has a shock foam retainer around the opening of the reflector. I don't anybody else who offers that feature. Maybe some comm's with Dave might be in order? I'm leaning towards your initial statement.

Click to expand...

Well that's interesting.. this does have a foam retaining ring in front of the drop in. Like a shock isolator. It's actually a pita to get it right . That's why I didn't unscrew the bezel and remove it entirely for photos. I want to grab another head just to run incans so I can switch it up.