# Using AA batteries to replace D batteries?



## mummel (Jan 5, 2015)

I've seen these plastic AA to D cell converter shells. I was thinking about getting 3 X AA rechargeables to replace my Mag Lite 3 X D cell flashlight. In terms of performance and capacity, are using AA batteries recommended for this purpose? Thanks.


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## WalkIntoTheLight (Jan 5, 2015)

You can. I sometimes run my 4xD Maglite with 4 AA's put in 1xAA to 1xD converters. But I also have real NiMH D cells, and they perform for much longer, obviously. If you use single AA converters, you'll end up with only about 20% to 25% of the capacity of a real NiMH D cell.

There has been a couple of threads on this, and from what I recall, you should make sure that the converters can handle the current you need. Even cheap converters are probably okay for a Maglite, since they aren't powerful lights. For powerful devices, make sure it's a quality adapter.

Also, you can get adapters that take 3xAA cells and convert it into a 1xD cell. It triples the capacity, which makes it more practical, but you then have to use a lot of AA cells in that Maglite. And, 3 quality AA cells are starting to approach the price of a D cell, so it becomes less appealing from a cost perspective.

If you already have a charger that can charge D cells, I'd just buy NiMH D cells. Otherwise, give 1xAA or 3xAA to D cell converters a try. At the very least, it will prevent you from using alkaleaks in that light, and ruining it.


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## MidnightDistortions (Jan 5, 2015)

It isn't really a bad idea when you don't have regular D batteries but i suggest getting real D NiMH cells if you can spend the extra money for it. 1AA to replace a D cell won't have near the amount of the capacity as a real D cell. 2AA to D is better, i still have to try 3AA to D, but you kinda get the picture, the more batteries the more run time you'll get out of each D cell adapter. However you'll get one of the best run times with some 11,000mAh Powerex.


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## mummel (Jan 5, 2015)

This is helpful, thanks guys.


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## StorminMatt (Jan 5, 2015)

WalkIntoTheLight said:


> Also, you can get adapters that take 3xAA cells and convert it into a 1xD cell. It triples the capacity, which makes it more practical, but you then have to use a lot of AA cells in that Maglite. And, 3 quality AA cells are starting to approach the price of a D cell, so it becomes less appealing from a cost perspective.



A pair of good D cells (Tenergy Premium or Centura) cost around $18. So depending on where you get your AAs and which ones you buy, the cost of three AA cells can actually exceed the cost of one D cell. And this doesn't even factor in the cost of a 3xAA adaptor, which by itself can equal or exceed the cost of a true D cell. The bottom line here is that the cost of three AA cells AND one 3xAA adaptor will most certainly exceed the cost of a true D cell, while providing less capacity, higher internal resistance, and the inconvenience of having to charge three batteries vs just one. Yet, for whatever reason(s), LOTS of people look at this as the more economical and generally 'better' way to go than using true D cells (which are both widely available and quite inexpensive).


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## ronniepudding (Jan 5, 2015)

I think the right solution will vary depending upon your intended use for the light. If you're using the Maglite every day and like its performance, you could invest in NiMH D cells and charger as some others have suggested... That will provide good run times without the inconvenience of having to charge up 3 times as many AA cells. Or you could put the cash you would otherwise spend on the NiMH D-cell setup toward a new light that will run on AA rechargeables (presuming you have them already)... 

In my case, the mags serve mostly as emergency lights, -- and since I already had AA eneloops and charger, I didn't want to invest in a dedicated battery system to power the antiques which see infrequent use. I also felt like the 3AA-to-1D adapters I looked at were either too expensive or too cheap (unreliable) looking.

I've used Eneloop brand 1AA-to-D converters successfully in Home Depot Defiant 3D lights, but the problem with Mags is that the stock tail spring has a wide opening which lets the AA slip right through. So for the Mags I ended up making a custom home-made battery carrier out of PVC tubing and copper pipe end caps. The end result is that my 5D Maglite now takes 6AA, and my 2D Maglite now takes 2AA. I have a supply of alkaleak D cells on hand to use when needed, but they are not installed otherwise, and so are not endangering any devices with their caustic tendencies. The Mags thus configured do double duty as AA Eneloop storage devices, and I've got 8 charged cells on hand waiting for a power outage, etc.


Sent from my iPhone using Candlepowerforums


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## Timothybil (Jan 5, 2015)

My only light that uses D cells is an old (I purchased in 2008) 3D lantern that I used because where I lived at the time was prone to power outages. Its main light was a Krypton bulb, with three 5mm LEDs as secondary lights. It still works great, but I got tired of buying D cells to let them die of old age. Everything else I have is either 18650 or LSD NiMH, so I got a set of the Eneloop 1AA to D converters. Since I have lots of AA NiMH cells around, and a better 4S2P Eveready Folding Lantern now for power outages, I can see no reason to continue to buy D cells.


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## JerryM (Jan 6, 2015)

I have two lights, Maglite and Kellite, that require 3 C cells. They are bedside lights and seldom used. When I get up in the night I use the moon mode of a Ti. Both are excellent lights, and I did not want Alkalines to leak and ruin them. The cost of rechargeable C cells was more than I want to pay for 6. I got AA to C adaptors and they work fine for occasional use. If I were to go on a trip where I wold use them I would go with Alkalines. Meantime the eneloop AA protect from Alky leaks.

Jerry


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## MidnightDistortions (Jan 6, 2015)

I got plenty of Eneloops and other AA NiMH rechargeables that are only up to a few years old so for now it's more economical to use the 3AA to D adapters, but as i said in the near future it's going to be more beneficial to get the real D NiMH cells as the need for using D size batteries will increase .


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## UserName (Jan 7, 2015)

StorminMatt said:


> A pair of good D cells (Tenergy Premium or Centura) cost around $18. So depending on where you get your AAs and which ones you buy, the cost of three AA cells can actually exceed the cost of one D cell. And this doesn't even factor in the cost of a 3xAA adaptor, which by itself can equal or exceed the cost of a true D cell. The bottom line here is that the cost of three AA cells AND one 3xAA adaptor will most certainly exceed the cost of a true D cell, while providing less capacity, higher internal resistance, and the inconvenience of having to charge three batteries vs just one. Yet, for whatever reason(s), LOTS of people look at this as the more economical and generally 'better' way to go than using true D cells (which are both widely available and quite inexpensive).[/QUOT
> 
> 3x AA adapters in parallel don't add a substantial amount of resistance. Resistances are additive when in series, not when in parallel. Adding the second cell to the adapter reduces resistance by half. Adding the third cell reduces resistance to a third.
> 
> ...


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