D cells and leaks

Historically one of my favorite light platforms was the D Cell Maglite. Lots of capacity, easy to use and due to the size hard to misplace. My main concern is leaking alkaline d cells. Now it's true that this can be completely avoided by storing empty but that's also not very convenient. Only option I can think of is d to aa adaptors with L91s but that's not very cost effective. Any other thoughts? Good quality adapters to use?

Any thoughts on the least leak probe D cells?

Nimh Ds are about your only choice but not really cost effective IMO compared to investing in a better battery format and light.

There are several good options. For single AA adapters, the current Eneloop branded ones with the closed bottom work pretty good and there are 3AA to D Parallel that also work good although some can be a bit dodgy in quality (test them out before relying on them).

Another option is NiMH D cells - I use 8000 mAh Tenergy Centuras and Soshine 11000 mAh's, with no issues with either, though I don't think they will keep up with Eneloops for low self discharge characteristics (probably best to charge them every 6 mo. or so).

In a 3 cell light, Li-Ions are a good option as well - I sometimes run single protected 18650's in my 3 cell ML300 in adapters that I 3D printed, works great. And like running single AA's, a 18650 in adapters is a lot lighter than using alkalines or NiMH D cells.

For a D cell light in regular use simply inspect frequently and discard the cells if leaking.
For spare or reserve lights don't store them with cells in them, fil them when needed.

Be aware that use of multi voltage LED bulbs greatly increases the chance of battery leakage due to the lower voltage reached before the light dims.

I recently bought a 2D Incan Maglite so I could recall how terrible the output was from it when I was originally issued one back in the 1980's.

I have since invested in a Firefly 800 Lumen upgrade, which has low, medium and high and was made for a 3-6 D cell light.

Because it can be used in a 6 cell light the maximum voltage is 9v, so I now run it on 2 x 26650 batteries (maximum 8.4v).

I also bought a shorty spring, a 26650 body tube and a small magnet to ensure that a 26650 makes contact in the Maglite.

All the parts are available from Adventure Sport Flashlights, however you may be able to source them from other sellers and reduce the cost of the conversion.

The conversion is completely reversible.

Dave D said:

I recently bought a 2D Incan Maglite so I could recall how terrible the output was from it when I was originally issued one back in the 1980's.

I have since invested in a Firefly 800 Lumen upgrade, which has low, medium and high and was made for a 3-6 D cell light.

Because it can be used in a 6 cell light the maximum voltage is 9v, so I now run it on 2 x 26650 batteries (maximum 8.4v).

I also bought a shorty spring, a 26650 body tube and a small magnet to ensure that a 26650 makes contact in the Maglite.

All the parts are available from Adventure Sport Flashlights, however you may be able to source them from other sellers and reduce the cost of the conversion.

The conversion is completely reversible.

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Sounds like a real nice set up!

X2 on the eneloop and adapters. But...for added runtime buy some eneloop pro's too.

In a pinch store bought lithium cells can provide primary fuel and will fit in the adapters.

I've been having good luck with Rayovac batteries for a few years now and have a few lights around the house with them. These days alkalines leak from chemical reactions occuring faster than the cell can handle them without gas build up. Stuff like extreme draw and temperatures contribute. It's always been that way but the cases are being made better these days. I still avoid coppertop bunney brands and only use Rayovac in flashlights.

I was looking at this issue recently and noticed that Energizer has a leak-proof guarantee on their AA and AAA alkaline cells, but not on anything larger.
Only mentioning this because I haven't seen anybody else mention it.

I know I'm a little late to the party but there are several things you can do to really cut down on leaks from alkalines. I read a lot that scared me into thinking every set of alkalines would leak and destroy my light but it's commonly from misuse or cheap batteries. I use Duracell Pro Cells but any premium battery will work. Make sure you use 3 brand new batteries. Do not mix and match old used ones. Even a slightly different voltage will leach the voltage out of a higher voltage cell and cause it to explode. The Pro Cells have a 10 year shelf life and likely another 3 or 4 past that. I've gotten lights that had Duracells that were 10 years expired so basically they went 20 years on the same set.

Pvc spacer for 26650 and dummy cells or https://www.amazon.com/dp/B01MEF4K44/?tag=cpf0b6-20
3 lithium primary per

delus said:

I was looking at this issue recently and noticed that Energizer has a leak-proof guarantee on their AA and AAA alkaline cells, but not on anything larger.
Only mentioning this because I haven't seen anybody else mention it.

Click to expand...

Probably because larger items when they leak cost a lot more to replace like boomboxes and lanterns and toys. They don't really think their batteries won't leak they just figure they can charge you more if you think they won't and then treat you the same as other companies that charge less and don't pretend their batteries won't leak.