They do and yes you will...

Good idea.

Battery manufacturers define "shelf life" as the amount of storage time (in years) until the battery has lost some specified amount of its original capacity (typically, 20 percent).

That's where the 7 year figure for alkalines stored at room temperature comes from: In 7 years, they've lost 20 percent of their original capacity.

Note that a battery's loss in capacity over time is linear - If it loses 1 percent over a year, it'll lose 2 percent over 2 years, and so on.

So, if storing a battery at 32 degrees F causes it to lose 3 percent of its original capacity in 7 years, it'll lose 20 percent of its original capacity in around 47 years!

A shelf life of 7 years is over 6 times shorter than a shelf life of 47 years.

I was actually thinking the exact opposite.

I bought a 16 pack of Duracell alkaline AA's probably 5 years ago ... just went to find it and the batteries "expired" in Mar 2015.  It doesn't list then they were made, but I assume 4-5 years ago.

Funny thing is, I still have 3 left in the pack!

So I only use a few a year, and that's with living with 2 other people.

Let's see ... 1 every other year or so for Yamaha receiver remote control ... A wireless mouse burns another about every year ... that's about it.

I have never understood the AA craze, or how people manage to burn through so many.  Is it just kids toys that always need AAs?

Anything quality ... doesn't run on AA, let alone AAA.  I think the only thing I own that takes a AAA is a TI calculator.  Seriously.

I've bought more 9v batteries in the past few years to replace beeping smoke alarms in the building hallways than I have anything else ... excluding 3400 mAh 18650s, which is really what you should be buying.

Well that's the exact point ... a lithium ion cell of D size is going to be capable of much higher voltage than 1.5 volts.

That's a good thing, as most LEDs like to be driven in the 4-9 volt range ... it just makes them incompatible with old hardware that can't handle the voltage.

Personally, I think it makes more sense to get a new light that can handle the latest battery tech ... then to ask manufacturers to make an expensive, watered down lithium ion battery that delivers "old" voltage requirements.

I say this as someone who also went on a hunt for D cell lithium ion cells to power a 6D mag lite I bought 10 years ago ... only to find that it was flawed thinking, and I would be better suited with a different strategy.

Now, if someone made a nice LED drop in made to run on higher voltage ... and you could use 3.6v lithium ion D cells in your old maglite ... that would be interesting.  A 22v, 6 3.6v D cell mag lite with adjustable beam would be a monster with huge capacity if someone would build the circuitry, but at that point it's super niche market and the niche market has moved onto 18650s, 26650s, etc.

Unfortunately, even Malkoff Devices Maglite drop ins are only spec'd for voltage ranges that normal alkaline D cells would provide ... 6-9v max depending on the model ... no go.

I think that he wants lithium D batteries, not lithium-ion 32650 3.6v cells.

Like Energizer's Lithium Ultimate and Advanced AAs and AAAs.

Much better at the temperature extremes, a shelf life of 25 years and generally a higher ~1.80v out of the pack state of charge.

They'd be spendy, but still cheaper than good Tenergy, Maha and AccuPower D NiMH batteries.

I've got an 02 Cool 10" 12v fan that runs on 8 D batteries and mulled over spending the money on NiMH batteries and a charger, or just gut it out with the alkaleaks and hope they last.

I went with the latter, but spending a couple of bucks more on lithium D batteries might have been the even better play.  I guess I could get a few 3 32650 li-ions and use spacers, but just getting 8 Eneloop AA>D adapters would be the cheapest route.

Chris

Hmm... My eotech runs on AA's.  Is that not quality?

But yes, lots of kids toys run on AAs and AAAs.

Ed-zackry. That's why I said, "I'd pay handsomely for lithium D cells..."

To be clear, we don't have a lot of devices that use D cells, but those that do are quality gear and need to either be fed with batteries or thrown in the trash. I've still got three maglites and one other (forget the brand/model) D-cell LED flashlights, and several family members also have D-maglites; many of which were gifts from us over the years. The benefits of lithium primaries are substantial enough that it would be nice to have both the added runtime and added shelf-life of lithiums with D's, just as we have with AA's, AAA's, and 9-volts.

It's not keeping me up at night or anything, but it sure would be nice and is definitely something I'd pay extra for. Most of our lights (and other things) nowadays are CR123 or AA units; definitely agree with the concept of latching onto newer tech at times. But there are times when that's not an attractive option - our survey meters are all D-cell units, and there's no way around it as they were made in the 50's-60's and they are what they are. For those and a few other things, the only reasonable options that I know of are either plain old alkaline D's or D-adapters for AA lithiums. (We do both.)

Whether or not it would be economically viable for any mfr to actually make them, I can't say. I assume not, since nobody does. But they'd sure sell me some, and I suspect there are a lot of people - and a lot of agencies - with D-cell flashlights that would switch to them in a heartbeat. Right now we pay $1.70 for AA Ultimate Lithiums; I'd probably pay $6-$8 without complaining for D's.

Since you're willing to pay some cash, just go out and buy a Maha 808M 8 bay charger and some Tenergy Premium NiMH D batteries.  I was looking last night on Ebay and other places and we can get them for as little as $7.29 at Battery Junction and on Ebay at about ~$60 for 8, shipped.

They get good marks and are cheaper than the Maha/PowerEx and Accupower brands and at 10,000mAh, they're right there with them in capacity.

The Tenergy Centuras are their LSD (low self discharge) offering, but have a bit less capacity.

Chris

Regarding the Eotech ... lots of people would say "no", unfortunately.

It's my favorite reticle to use, I used to own 2 of them, but reliability over the years has been ... sketchy, to say the least.  No shortage of battery / system failure threads on arfcom regarding EOtechs.

You are in a situation where you need to use Eneloops. They are rechargeable NiMH AA cells and they actually perform better under heavier loads than Alkaline stuff.

You will save lots of coin over the years.

There are some applications where Lithiums make sense. They have advantages of:

1. Work in cold weather when Alkalines shut down

2.  Don't leak

3. have much higher capacity especially under heavy load.

I use either L91 lithiums, CR123A or plain eneloops.

Alkalines in all sizes have ruined plenty of devices for me.

s

I gave a D sized Mag to someone and they lost it due to leaky cells.  This is the pattern. Discharge it. Then keep bad discharged cells in it for a year, especially in cold weather. The cells leak, destroy the light. AA, C and D alkalines.

There is no market for this... but I hear you.

Everyone is moving into rechargeable cells. The D cell under a heavy load has the same capacity as 18650 cell. Which is smaller. Incredible but true.

The D cell and it's very high mAh rating makes sense for a very low mAh device.