# Why don't they make rechargeable lithium AA/AAA batteries?



## jcc39 (Jun 9, 2006)

As the title states, why aren't AA/AAA rechargeable lithium batteries available? They sell them in non rechargeable so why not rechargeable? I've searched all over the net for an answer and haven't found anything. Isn't this the next logical step above NiMH rechargeables? Thanks for the info.


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## Blindasabat (Jun 9, 2006)

They do sell them, they are just rare. There is some liability to Li-Ion and even more making them fit where a regular consumer AA fits, since they are much higher voltage. They will destroy most products made to use 1.5V AA's since they run 3.7V to 4.2V fresh off charger. Explosion and fire is a real danger.
Look at AW's Battery sales thread in the Dealer's section if you have something that can take the voltage of Lithium Ion's. They are called 14500 (14mm OD, 50mm long).


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## nerdgineer (Jun 9, 2006)

The only rechargeable lithium technology is lithium-ion, which inherently runs at 3.7 or so volts output. There is no rechargeable lithium battery technology that runs at the 1.5-1.9 volts output of the typical lithium AA/AAA primary batteries. So the answer as to why they haven't done it is they don't know how yet.

I expect they're working on it and whoever gets it right first (with a high current capacity, high energy density, long latency, long lifetime, and not too afraid of overcharge/overdischarge rechargeable 1.5 to 2.0 volt AA/AAA battery) will make a fortune.

If you're referring to AAA/AA rechargeable lithium-ions, those ARE made and available. On source is CPFer AW.


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## tebore (Jun 9, 2006)

I thought they have Li-Po Batteries that are also rechargable... I've been out of the RC world for too long and the last thing I made used gas. 

Li-po doesn't come in AA format but I'm just saying Li-ION isn't the only rechargable Li battery out. Correct me if I'm wrong.


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## SilverFox (Jun 9, 2006)

Hello Tebore,

The proper name for Li-Po batteries is Li-Ion-Polymer. It is a form of the Li-Ion battery.

Tom


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## monkeyboy (Jun 10, 2006)

How do they cut the voltage in half for non-rechargeable lithium batteries? And why can't they do the same for li-ion?

I've seen li-ion cells rated at 3.7v and 3.0v. How do they reduce the voltage from 3.7 to 3.0V?

I would imagine, if they made protected AAA Li-ion, the protection circuitry would take up a large proportion of the battery. What I would like to see is; double length D size li-ion batteries that could be used in 2D, 4D, 6D maglites etc. and double length AA versions as well.


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## nerdgineer (Jun 10, 2006)

monkeyboy said:


> How do they cut the voltage in half for non-rechargeable lithium batteries? And why can't they do the same for li-ion?
> 
> I've seen li-ion cells rated at 3.7v and 3.0v. How do they reduce the voltage from 3.7 to 3.0V?
> 
> I would imagine, if they made protected AAA Li-ion, the protection circuitry would take up a large proportion of the battery. What I would like to see is; double length D size li-ion batteries that could be used in 2D, 4D, 6D maglites etc. and double length AA versions as well.


I believe the non-rechargeable lithium batteries use different chemistries - which happen to have lithium in them somewhere - that yield lower voltages but can't be recharged. I think 3.0 volt lithium primaries are lithium manganese hydroxide (?) and the 1.7 volters are lithium something else. 

I believe the 3.0 V lithium ions use a circuit to push back on the natural 3.7 V li-ion ouput, yielding a net voltage of about 3.1 or 3.2. The circuit, like a resistor, will eat up some of the battery energy and produce some heat in doing this.

The 2xD (and 2xAA) li-ion battery has been suggested before and would work. However, you need a big up front investment to create a new li-ion battery design and I'm again guessing that the investors don't quite see the market to justify such a new investment. 

There are only a few CPFers, not nearly enough to justify a new battery design. Most 2xD cell lights cost $5 or less and their owners would likely not spend the $25+ needed for such a battery, plus more for the charger. Ditto with 2xAA versions. Remember, li-ions are only good for 3 years or so whether you use them or not, so it would not replace an endless supply of D cells or AA cells.

There's also the small but not insignificant risk of mishaps with such a large li-ion cell, even protected ones. I think a worst case explosion with one that big could take your hand off, and that creates a further liability disincentive to producing one.


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## monkeyboy (Jun 12, 2006)

nerdgineer said:


> There's also the small but not insignificant risk of mishaps with such a large li-ion cell, even protected ones. I think a worst case explosion with one that big could take your hand off, and that creates a further liability disincentive to producing one.


 
Now I'm afraid to put my mobile phone in my trouser pocket.


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## nerdgineer (Jun 12, 2006)

monkeyboy said:


> Now I'm afraid to put my mobile phone in my trouser pocket.


By "that big" I meant the size of 2xD cells. Unless you have a really OLD mobile phone, the battery in it is probably no larger than a pack of matches (and carefully protected, too)...


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## altis (Jun 15, 2006)

No one has mentioned the rechargable CR-V3 which neatly gets around the voltage problem by replacing two AAs side-by-side. Trouble is that, with only 1200mAh, the capacity is not very good and you're better off using NiMh technology anyway.


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## Nuxtux (Apr 7, 2016)

Hello. I been a member here and mostly just lurk. Sometimes not even logging in. Would like to know if with the battery technology in cellphones and Telsla is there any chance of AA batteries to be rechargeable?

I just use them for my Xbox 360 controller and flashlight for building stuff in tight spaces.


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## FRITZHID (Apr 7, 2016)

Would be nice but I'm not sure the chemistry is compatible. I've seen lithium primaries in both 1.5 & 3.7 volts but nothing rechargeable. I could use some lithium ion D cells for a few projects but the 3.7v version can run as high as $20/cell.... For primaries! Insane price for a use and toss battery.
I could see uneducated peoples using 3.7v aa/aaa rechargeables in something ment for 1.5v just because they fit and causing damage, fire or possibly worse.
I'm sure there's a good reason they don't make them and someone may pop in and be more specific as to why.


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## mcnair55 (Apr 7, 2016)

jcc39 said:


> As the title states, why aren't AA/AAA rechargeable lithium batteries available? They sell them in non-rechargeable so why not rechargeable? I've searched all over the net for an answer and haven't found anything. Isn't this the next logical step above NiMH rechargeables? Thanks for the info.



I doubt the battery makers see a demand and presently most makers are working flat out on automotive propulsion.


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## Gauss163 (Apr 7, 2016)

This was discussed in the prior thread Lithium 1.5v rechargeable batteries... why not? As I mentioned there, the article A look at future battery chemistries gives a nice glimpse into the design decisions involved in constructing a rechargeable battery. It explains briefly how anode/cathode elements are chosen from the periodic table to meet various design constraints (including voltage). This will help you to understand why you cannot construct a 1.5V Li-ion cell.


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## Gryffin (Apr 7, 2016)

nerdgineer said:


> The only rechargeable lithium technology is lithium-ion, which inherently runs at 3.7 or so volts output. There is no rechargeable lithium battery technology that runs at the 1.5-1.9 volts output of the typical lithium AA/AAA primary batteries. So the answer as to why they haven't done it is they don't know how yet.



Actually, one company *did* try to market rechargeable cells with a completely different chemistry. They were called PowerGenics, if I recall correctly; the batteries were a nickel-zinc chemistry, which has actually been around forever, PG just claimed to have overcome some of the limitations. Unlike pre-Eneloop NiMH cells, self discharge was low, and they were much more resistant to charge "memory" than NiCd, too.

Voltage was ~1.6V nominal, but something like 1.9V hot off the charger; this was a BIG problem when used in series in devices that expected 1.5V (alkaline) or 1.7V (Energizer Lithium) at most; I heard plenty of accounts from photographers that they fried their flash units using PG's NiZn batteries.

Unfortunately, NiZN cells required separate chargers. Also, they never fully overcame the chemistry's inherent flaws, such as limited recharge cycles, and deteriorating capacity with more cycles; just around the same time, Eneloops hit the market, so self-discharge was no longer a reason to not use NiMH any more, and PowerGenics closed up shop soon after.

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UPDATE: After posting that, I thought I'd try googling PowerGenics and NiZn batteries. Turns out the company is still around, but I got the name wrong, it's PowerGenix; they *did* exit the consumer market, but are still marketing their NiZn cells for industrial use. 

More on NiZn cells: https://en.wikipedia.org/wiki/Nickel–zinc_battery

Kinda sad they never caught on, there's a lot to like for us flashoholics: high energy density, VERY high discharge rates, and high recharge rates (1C). Ah well…


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## mcnair55 (Apr 7, 2016)

Gryffin said:


> Actually, one company *did* try to market rechargeable cells with a completely different chemistry. They were called PowerGenics, if I recall correctly; the batteries were a nickel-zinc chemistry, which has actually been around forever, PG just claimed to have overcome some of the limitations. Unlike pre-Eneloop NiMH cells, self discharge was low, and they were much more resistant to charge "memory" than NiCd, too.
> 
> Voltage was ~1.6V nominal, but something like 1.9V hot off the charger; this was a BIG problem when used in series in devices that expected 1.5V (alkaline) or 1.7V (Energizer Lithium) at most; I heard plenty of accounts from photographers that they fried their flash units using PG's NiZn batteries.
> 
> Unfortunately, NiZN cells required separate chargers. Also, they never fully overcame the chemistry's inherent flaws, such as limited recharge cycles, and deteriorating capacity with more cycles; just around the same time, Eneloops hit the market, so self-discharge was no longer a reason to not use NiMH any more, and PowerGenics closed up shop soon after.



Nice bit of info to read through.


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## eh4 (Apr 8, 2016)

Nuxtux said:


> Hello. I been a member here and mostly just lurk. Sometimes not even logging in. Would like to know if with the battery technology in cellphones and Telsla is there any chance of AA batteries to be rechargeable?
> 
> I just use them for my Xbox 360 controller and flashlight for building stuff in tight spaces.



Nuxtux, we have excellent rechargeable AA now, search CPF for "Eneloop".


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## NoNotAgain (Apr 9, 2016)

There are AA sized lithium ion batteries, but they're called 14500 batteries. With over three times the voltage of alkaline or primary lithium batteries, a few used in series will toast most items designed for the 1.5 volt battery.

It's a good thing they aren't plentiful as they'd fry most electronic items currently on the market.


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## KeepingItLight (Apr 9, 2016)

Gauss163 said:


> This was discussed in the prior thread Lithium 1.5v rechargeable batteries... why not? As I mentioned there, the article A look at future battery chemistries gives a nice glimpse into the design decisions involved in constructing a rechargeable battery. It explains briefly how anode/cathode elements are chosen from the periodic table to meet various design constraints (including voltage). This will help you to understand why you cannot construct a 1.5V Li-ion cell.



Thanks for the links! 

I had not seen these before.


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