Building a 2x-AA P60 for a friend...

Flashlight Modding and DIY Parts
1

I have a friend who I do not trust with Li-Ion cells. I know he will run them down to flat and forget about them on the charger for hours. A couple of years ago, I assembled him a P60 with a nice bright emitter and a high-voltage driver so he could run from the CR123a primaries I gave him with the light. A while back, he asked me to look at his light as he thought something was wrong with it. He said was getting hot and draining his batteries. I checked it out and it worked properly so I asked him about it. As it turns out, he was using his flashlight at his job. He works in an automotive shop, and was using his light for extended runtimes throughout the day. Of course it was getting hot and eating primaries!

I know that AA P60s aren't widely availble since Solarforce discontinued the L2r AA host. I couldn't find any decent budget AA lights. Most are like the C3 and I wanted him to have something nicer than that. Ultimately, I decided to build him up a custom 2xAA P60 using the 501c body with spacers.

I ordered a pair of 501c hosts from Kaidomain (My first ever KD order, we'll see how that goes) as they seemed to be the cheapest source of the 501c body.

http://www.kaidomain.com/product/details.S004292

The 501c is designed to run from 3x CR123A-sized cells; 2 AA cells connected end-to-end happen to be the same length, so with a sleeve in the battery tube to take up the extra space, it should work well.

I purchased an empty OP drop-in and XP-G 2 emitter to use with this FastTech driver:

https://www.fasttech.com/p/1127407

...along with a 4-pack of Enelong LSD cells...

https://www.fasttech.com/p/1140600

...and a budget charger:

https://www.fasttech.com/p/1229401

I'm looking forward to building this up to see how well it works for him. I'm hoping that the lower-powered drop in (with access to lower modes) will give him the runtime he needs while still being bright enough to be useful, all without "venting with flames" and chewing up stacks of expensive 123a cells...

2

Put the light together last night and I am very impressed! I used a cool-white XP-G2 emitter with an OP XP-G reflector. Using the driver I listed from FT (https://www.fasttech.com/p/1127407), I get a good useable brightness on high @ ~800mA as per spec. There is no mode memory, and the mid is ~450mA and the low is still very useable @ ~180mA IIRC. I didn't notice any PWM while playing with it last night either. Should be good on low for long runtimes from AA Alkaline and NiMH rechargeables. The budget charger was DOA, the cells I bought seem good (they work, but haven't been tested for runtime). Now, to find a proper-sized tube for the 18650 -> AA adaptor and it will be ready to use.

3

FWIW - A while back I asked here about a tube to use as an adapter and the best suggestion I received was to make one out of rolled paper.

I cut some strips of copier-type paper such that the width of the strips was the length I wanted the adapter to be. I taped a couple AA batteries together and then wrapped some paper around them so when I made the adapter the batteries would not fit too tightly in the newly made adapter tube. (Does that make sense?)

Then I wrapped the paper strips around the battery / paper deal I just made, using a glue stick to hold the layers together as I wrapped. I checked the width of the adapter as a I added layers until it was just the right fit for inside my flashlight body. When it was, I wrapped it with a layer of plastic tape, pulled out the battery / paper assembly, trimmed it as needed to be the right length, and then inserted it into my flashlight body.

It works great.

4

Sounds like a good mod. I hope your mate likes it. Hes lucky to have a friend like you.

5

My friend is loving his flashlight... He's been using it extensively every day at his work and is very happy to have it. He says the other mechanics there have standard cheap LED lights that aren't bright, and his is the best in the shop. I'm actually surprised as he's been using it for about 2 weeks now and says that he is still using the first pair of cells; he hasn't had to swap them out or recharge them yet! I assume he is normally using it on a low setting and doesn't spend much time on "High".

For the battery tube, I ended up using a piece of standard EMT conduit cut to length. I put a layer of shrink wrap outside the tube which made it a tight fit into the battery tube of the light. It centers the cells well, prevents excessive rattle, and is removable if necessary.