True 1.5v AA and AAA batteries

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,969
Location
Southern Ontario
I tried a lot of putting higher wattage bulbs in lights, but I've never been a fan of overdriving LEDs or lamps.
An exception is turbo modes for brief use. That was never a thing on any hot wire light I've used.

3V vs 2.6V, say, is extremely different as far as bulb life-span. But, sure, it's your bulb! That is a reasonable level of overdrive. IDK how many hours you'll get, but it's not going to pop it, and I doubt it would melt anything. I'm... just perfectly happy with alkaline or NiMH in minis. Back in the 80s, I thought it was uber cool to use 600mAh red & yellow Sanyo RC car AAs in mine. Albeit, they died in <2h.

And, I agree, if you're going to use your alkalines for <2h before (i hope) using them for some less demanding use, then, alright, that's probably about the same thing.

Oh, the other use: remote controls. You ever had a remote that cares about 1.5 vs 1.2? Mine all seem to work exactly the same, but the battery reviews seem to say that 1.5 is a godsend for some remotes.
Agree that eneloops are fine in almost all devices. The only issue I've ever had was a thermostat.
Yes, it is a bit of overdrive, but I don't think it's as much as some think. While alkaline do sag, it's not immediate. Maglites were Actually pretty decent with fresh cells. For a few minutes. Then they went orange. So for that first couple minutes, it was close to 1.5 V per cell. So I don't think it's that much overdrive. I have about five hours on one bulb, with these regulated cells. So far so good.
Also, in my minis, I am using eneloops. The only light I'm using these regulated cells in, is an ml25it. It is another to cell light. But it is using cells. So the bulb draws about an amp. Instead of the 300ma the mini uses.
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
Agree that eneloops are fine in almost all devices. The only issue I've ever had was a thermostat.

Gads, yes. The new one craps out at about 1.4V! Just use 3 cells if you need more than 2.2V.

My old thermostat ran a decade without asking for batteries. I didn't even know it had a (leaking) set of alkalines in it until I replaced it. I assumed it was wall-powered. Really should open my furnace and connect that wire... But, it has run over a year (two?) off ultimates, so I may not bother.

I have about five hours on one bulb, with these regulated cells. So far so good.
Also, in my minis, I am using eneloops. The only light I'm using these regulated cells in, is an ml25it. It is another to cell light. But it is using cells. So the bulb draws about an amp. Instead of the 300ma the mini uses.

Sounds about right. In the ballpark of 25% lamp life. Not for me, but not unreasonable for "us folks" :)
Quickie Google says 25% life (and 140% lumens) at 10% overvoltage. 3.0 vs 2.5 (alkaline avg?) should be 5% life, but I'm not sure how well the data I found applies to minimag bulbs. They're certainly not the most common size/rating, and they're xenon vs what they may mean by "gas filled". And, IDK what mag's spec is, vs most 2 cell flashlight bulbs being 2.4V.

I only use incandescents for nostalgia's sake, and I buy 2700K LEDs when they're an option, so 2.4V mini mag light color is perfectly to my taste.

What seems irrational, for myself, is buying the bulk (40?) pack of minimag lamps last time I ordered from maglite ML150LR (the wall-mount Li rechargeable). It is possible they'll discontinue the part, but I'm, at the very least, set for life at this point.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,969
Location
Southern Ontario
Gads, yes. The new one craps out at about 1.4V! Just use 3 cells if you need more than 2.2V.

My old thermostat ran a decade without asking for batteries. I didn't even know it had a (leaking) set of alkalines in it until I replaced it. I assumed it was wall-powered. Really should open my furnace and connect that wire... But, it has run over a year (two?) off ultimates, so I may not bother.



Sounds about right. In the ballpark of 25% lamp life. Not for me, but not unreasonable for "us folks" :)
Quickie Google says 25% life (and 140% lumens) at 10% overvoltage. 3.0 vs 2.5 (alkaline avg?) should be 5% life, but I'm not sure how well the data I found applies to minimag bulbs. They're certainly not the most common size/rating, and they're xenon vs what they may mean by "gas filled". And, IDK what mag's spec is, vs most 2 cell flashlight bulbs being 2.4V.

I only use incandescents for nostalgia's sake, and I buy 2700K LEDs when they're an option, so 2.4V mini mag light color is perfectly to my taste.

What seems irrational, for myself, is buying the bulk (40?) pack of minimag lamps last time I ordered from maglite ML150LR (the wall-mount Li rechargeable). It is possible they'll discontinue the part, but I'm, at the very least, set for life at this point.
No, that bulb that has five hours on it is still going strong. It seems perfect still it has not burned out. Actually, I have not burned out an incandescent lamp in a long time. I don't even worry about it anymore. They seem to last forever. I probably have about 25 hours on a six sell magnum star. I'm running it on two high drain lithium ions. And I like to keep the cells topped up. So that bulb is getting over 8 V. And it's still going. I want it to burn out so I can replace it with a little bit stronger tad customs bulb, but it won't die
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
No, that bulb that has five hours on it is still going strong. ...

Interesting. I googled further and it's all like 5% life at 20% overvoltage. That lamp must be different. It does have a REALLY short filament.
~8.2V to a 7.2V bulb? 14% overdrive. Yeah, I think the charts are for 12V indicators or 120V illumination.

I'll have to try it. Weird I never have. I'm curious to probe the lamp's pins and see what kind of voltage drop there might be. Even 0.2V drop would make a big difference.
 

alpg88

Flashlight Enthusiast
Joined
Apr 19, 2005
Messages
5,395
Some bulbs take overdrive better than others. I had 2 oem bulbs burn in 6d using li ion 1.5v cells. it was not an instaflash, but they barely lasted 2 ch/dch cycle of batteries, I can not say I saw any noticeable increase in brightness. iirc correctly krypton bulbs take overdrive better than magnum star xenons. Ms are made to be brighter, so their filament is thinner and burns hotter, basically on the edge of burning out.
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
Measured at the pins, xenon minimag, fresh alkalines or Hixon 1.5V: 2.65-2.70V. So 10% overdrive, not 20%, and that's assuming it's a 2.4V lamp, which it may not be. Nor do I know at what point the "4-5 sets of batteries" cutoff voltage or time is.
Bonus, the aluminum body shields all the RFI. I can put the MM right next to an AM radio.

I'm not sure I like the full-voltage whiteness when it's more for nostalgia than utility, but hey, TIL: minimag is a good use of 1.5V AAs.
 

alpg88

Flashlight Enthusiast
Joined
Apr 19, 2005
Messages
5,395
OTOH, some bipin halogens take overdrive like champs, and we used to use it back in incandescent era. 90w 12v osram bipin takes 20v around 200watts, and about 2x as bright. so do long life mr16 take 5 li ion cells burn twice as bright.
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
I've discovered my new favorite "1.5V Constant Voltage" AAs actually have a slowly decreasing voltage. I guess to make battery gauges in equipment somewhat useful, more so than the ones that drop suddenly to 1.1V as a low battery indicator. The selling point for me is how cute the charger is. You put them positive-end down in little green LED lit holes and the light turns orange while they charge. + and - are on the + end so the negative end just sticks up in the air. And, far as I know, you shouldn't try charging them using the negative terminal in a normal 1.5V Li charger. It's adorable. I didn't notice the voltage curve until I observed it on my LED candles, 2 with these, 1 with the blue Hixon 3500 batteries (no low-level indicator at all).

A little hard to find, and just available as a 4xAA 4xAAA charger kit for about $30. (vs $35-45 for other AA 8pk of similar types). Models are "ST5" AA and "ST7" AAA but no luck searching for those now.
ASIN: B0C6PFGQTL "https://www.amazon.com/dp/B0C6PFGQTL?tag=cpf0b6-20

So... if you don't recharge them immediately, they only hold 1.5 for the first 25%. By 75% use, they're down to fresh NiMH 1.3V. MiniMag bulb would last longer, yet still be brigher than alkaline or NiMH.

Another factor is fit. My white XTAR are too wide. Blue or orange Hixons fit easily. These EBLs are almost a tight fit. They slide out, they don't drop out. Haven't tried my red EBLs or the XTAR with low voltage indicator.
 

letschat7

Flashlight Enthusiast
Joined
Dec 7, 2022
Messages
2,624
Location
West Virginia, North America
XTAR 1.5 v Lithums are trustworthy as far as quality goes but I couldn't get them to work in Led Lenser type lights that are multicell AAA. They aren't for every application but neither is lithium AAA or nicad AAA or carbon zinc AAA.
 

aznsx

Flashlight Enthusiast
Joined
Apr 24, 2015
Messages
1,737
Location
Phoenix, AZ USA
I've discovered my new favorite "1.5V Constant Voltage" AAs actually have a slowly decreasing voltage. I guess to make battery gauges in equipment somewhat useful, more so than the ones that drop suddenly to 1.1V as a low battery indicator. The selling point for me is how cute the charger is. You put them positive-end down in little green LED lit holes and the light turns orange while they charge. + and - are on the + end so the negative end just sticks up in the air. And, far as I know, you shouldn't try charging them using the negative terminal in a normal 1.5V Li charger. It's adorable. I didn't notice the voltage curve until I observed it on my LED candles, 2 with these, 1 with the blue Hixon 3500 batteries (no low-level indicator at all).

A little hard to find, and just available as a 4xAA 4xAAA charger kit for about $30. (vs $35-45 for other AA 8pk of similar types). Models are "ST5" AA and "ST7" AAA but no luck searching for those now.
ASIN: B0C6PFGQTL "https://www.amazon.com/dp/B0C6PFGQTL?tag=cpf0b6-20

So... if you don't recharge them immediately, they only hold 1.5 for the first 25%. By 75% use, they're down to fresh NiMH 1.3V. MiniMag bulb would last longer, yet still be brigher than alkaline or NiMH.

Another factor is fit. My white XTAR are too wide. Blue or orange Hixons fit easily. These EBLs are almost a tight fit. They slide out, they don't drop out. Haven't tried my red EBLs or the XTAR with low voltage indicator.
I'm not currently in the market, but this is good info to know, and I'm sure it ain't in the specs;-)
Thanx.
 

Bryan-ba

Newly Enlightened
Joined
Apr 22, 2024
Messages
11
Location
Hattiesburg, MS
Rayovac used to sell a "rechargeable alkaline" that behaved much more like a regular alkaline and started at 1.5v, but the they have been gone a while. They are discussed here along with some "Pure Energy" rechargeable alkalines that I have no experience with.


I had some of the Rayovacs back in the day and I thought they worked well at the time. These days I am generally an Eneloop user, too. I have also found Watson MX and CX to be good. Rumor is the MX are rebranded Eneloop Pros (black) and the CX are rebranded Eneloops (white). The specs are the same and they have been interchangeable for me. At one time Amazon had an "Amazon Basics" battery that was made in Japan and rumored to be rebranded Eneloops, but I believe they are all made in China now. I have also had good luck with Powerex Precharged and Ansmann Low Self-Discharge, but I prefer Eneloop/Watson.
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,969
Location
Southern Ontario
I remember as a kid, rechargeable alkalines. I don't know, but now but back then they were absolute garbage. They only had about 10% of the runtime that alkalines dead. To the point where they weren't worth using.
 

fivemega

Flashlight Enthusiast
Joined
Jan 28, 2003
Messages
5,540
Location
California
"REACHARGEABLE" alkaline does not mean you can recharge them 10 or 100 times.
"REACHARGEABLE" alkaline does not mean they will be reliable just like new one.
"REACHARGEABLE" alkaline does not mean they will perform just like new one.

Voltage of any battery does NOT mean anything unless measured under certain and stated current load.
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
I'm not currently in the market, but this is good info to know, and I'm sure it ain't in the specs;-)
Thanx.
It's in the pictures and a graph on the amazon product page, but everywhere else it's just "1.5V".
I do love the vertical charging and pretty green/amber ring around the batteries. So far, no cells-only, but at $30 it's a good price for 8 cells unless you don't want both AA and AAA.
 

radellaf

Flashlight Enthusiast
Joined
Apr 10, 2002
Messages
1,100
Location
Raleigh, NC
I remember as a kid, rechargeable alkalines. I don't know, but now but back then they were absolute garbage. They only had about 10% of the runtime that alkalines dead. To the point where they weren't worth using.
I really got into them and, yeah, fivemega can use orange asterisks all over the place, but the RayOVac Renewals were... basically useless. They also, I think, got clobbered by LSD NiMHs like Eneloops that had most of the advantages and none of the problems. That other thread says "don't tell me they can't... {make them better}." I've read a lot of the papers on them and, more or less, no, they can't. Certainly not for consumer use. Maybe in some commercial application with really careful battery management. To what end? Zn and Mn are cheap and relatively environmentally friendly, basically. Once MnO2 becomes Mn2O3, you're basically done with that part of the cathode. Once Zn migrates out of the anode, again, irreversible.

They were good for a few charges unless you were meticulous about charging them at <50% or so, and even then we were talking maybe 20 charges of decreasing effectiveness. Voltage at any sort of load wasn't better than NiMH (remember, digital cameras using AA were a huge market for rechargeables). They leaked as bad or worse as primary alkalines, especially if recharged, and especially if recharged and left for any length of time. So, really only useful for frequently used things that you could keep swapping batteries in.

Just... not bloody worth it. At the very least, the Li 1.5 AAs don't leak. At the very worst, though, they seem to fail (or have low capacity) too frequently and... unlike NiMH, have a non-negligible chance of igniting. They do, however, maintain voltage at "high" loads. Making them quite useful for badly designed things, or things you want to be as bright, fast, or powerful as possible (at the possible sacrifice of motor or bulb life).
 

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,969
Location
Southern Ontario
I really got into them and, yeah, fivemega can use orange asterisks all over the place, but the RayOVac Renewals were... basically useless. They also, I think, got clobbered by LSD NiMHs like Eneloops that had most of the advantages and none of the problems. That other thread says "don't tell me they can't... {make them better}." I've read a lot of the papers on them and, more or less, no, they can't. Certainly not for consumer use. Maybe in some commercial application with really careful battery management. To what end? Zn and Mn are cheap and relatively environmentally friendly, basically. Once MnO2 becomes Mn2O3, you're basically done with that part of the cathode. Once Zn migrates out of the anode, again, irreversible.

They were good for a few charges unless you were meticulous about charging them at <50% or so, and even then we were talking maybe 20 charges of decreasing effectiveness. Voltage at any sort of load wasn't better than NiMH (remember, digital cameras using AA were a huge market for rechargeables). They leaked as bad or worse as primary alkalines, especially if recharged, and especially if recharged and left for any length of time. So, really only useful for frequently used things that you could keep swapping batteries in.

Just... not bloody worth it. At the very least, the Li 1.5 AAs don't leak. At the very worst, though, they seem to fail (or have low capacity) too frequently and... unlike NiMH, have a non-negligible chance of igniting. They do, however, maintain voltage at "high" loads. Making them quite useful for badly designed things, or things you want to be as bright, fast, or powerful as possible (at the possible sacrifice of motor or bulb life).
I do like my XTAR 1.5v cells. But I really don't see the need. Eneloop cover all the bases
I need. I just buy the ikea laddas. They're cheap and great. I haven't found a device yet that doesn't work well with the laddas. My minimag lasts forever on them. I am glad that rechargeable alkaline are no longer a thing. I actually had a hard time convincing a friend to get laddas for a couple of his devices as he'd had such bad luck with bad rechargeables. But he likes them now
 

aznsx

Flashlight Enthusiast
Joined
Apr 24, 2015
Messages
1,737
Location
Phoenix, AZ USA
One word y'all: NOISE. It's the elephant in the room that few want to address. It's a word that will make any experienced electronics professional cringe - especially me.

Here's a quote from a 'review' of some Xtars:

EDIT: I neglected to include acknowlegment of and thanx to 'sammyshp' for this quote:

************************************************************************************
"Another device I used for testing is a radio clock with external temperature sensors. At about 1.3V the display starts to fade, at 1.2V it is almost unreadable. And that's the normal voltage of NiMH batteries. With the XTAR batteries the contrast is always perfect. At the end of discharge the display would be unreadable, but the alarm would still work.

But there is a problem: The clock signal is only received when I bring the clock outside and the temperature sensors are not received at all! There must be some kind of interference with the batteries.

When checking the noise of the voltage with an oscilloscope at different loads it becomes obvious. I guess there was not enough room for proper filtering, but this limits the use of the batteries. It is likely they will cause trouble when used in something that receives radio signals."


XTAR_AAA_noise_measurements.png

"I tested the discharge at currents ranging from 600mA to 1600mA. Even at the highest load they provide 1.5V, but they will also heat up significantly. My test was open on the bench, so it will become a much bigger problem enclosed in devices."

***************************************************************************************************
Here's a quote from a user of a Tenavolt variant:

"Yeh, I got a clock/thermometer that takes 3 AAAs. 1 is for something and 2 are for something else. Forgot which is for the backlight-only and which is for the digital innards.

Either way, the backlight always works fine, as it's not picky, but when I switched from alkaleaks to… think they were Tenavolts… the buttons to set the clock, etc., just plain wouldn't work. It kept time, starting from 12:00:00 of course, but you couldn't set the time, switch from C/F or F/C, nuttin'."

****************************************************************************************************


Keep in mind that noise like this is not simply an electrical component of the 1.5V "DC" output of the cell, potentially affecting the device they're powering, but there are almost certainly electromagnetically-radiated components as well. I have seen no published specs on any of this from any manufacturer of cells of this type. I have seen no user precautions or guidance provided on any of this either. I've also seen no tests using a 'field strength meter' or spectrum analyzer yet.

One of the most problematic aspects of 'noise issues' is that they are frequently not binary / black-and-white issues, but such issues are often marginal, variable, or intermittent as well. Something may appear to work today, but be degraded or fail to work completely the next, depending on variable factors which may not be evident. Additionally, if it's interfering with an RF AV (or other) equipment remote (just for example since there's one sitting here), or increasing the BER (bit error rate) on a wi-fi or BT connection in the vicinity, will you know it? How much do you depend on RF devices / products in your environment? Are you sure you want to sign up for worrying about all this at this point in time?

These are things I consider, and everyone has to make their own subjective decision about.
 
Last edited:

vicv

Flashlight Enthusiast
Joined
Mar 22, 2013
Messages
2,969
Location
Southern Ontario
One word y'all: NOISE. It's the elephant in the room that few want to address. It's a word that will make any experienced electronics professional cringe - especially me.

Here's a quote from a 'review' of some Xtars:

EDIT: I neglected to include acknowlegment of and thanx to 'sammyshp' for this quote:

************************************************************************************
"Another device I used for testing is a radio clock with external temperature sensors. At about 1.3V the display starts to fade, at 1.2V it is almost unreadable. And that's the normal voltage of NiMH batteries. With the XTAR batteries the contrast is always perfect. At the end of discharge the display would be unreadable, but the alarm would still work.

But there is a problem: The clock signal is only received when I bring the clock outside and the temperature sensors are not received at all! There must be some kind of interference with the batteries.

When checking the noise of the voltage with an oscilloscope at different loads it becomes obvious. I guess there was not enough room for proper filtering, but this limits the use of the batteries. It is likely they will cause trouble when used in something that receives radio signals."


View attachment 61438

"I tested the discharge at currents ranging from 600mA to 1600mA. Even at the highest load they provide 1.5V, but they will also heat up significantly. My test was open on the bench, so it will become a much bigger problem enclosed in devices."

***************************************************************************************************
Here's a quote from a user of a Tenavolt variant:

"Yeh, I got a clock/thermometer that takes 3 AAAs. 1 is for something and 2 are for something else. Forgot which is for the backlight-only and which is for the digital innards.

Either way, the backlight always works fine, as it's not picky, but when I switched from alkaleaks to… think they were Tenavolts… the buttons to set the clock, etc., just plain wouldn't work. It kept time, starting from 12:00:00 of course, but you couldn't set the time, switch from C/F or F/C, nuttin'."

****************************************************************************************************


Keep in mind that noise like this is not simply an electrical component of the 1.5V "DC" output of the cell, potentially affecting the device they're powering, but there are almost certainly electromagnetically-radiated components as well. I have seen no published specs on any of this from any manufacturer of cells of this type. I have seen no user precautions or guidance provided on any of this either. I've also seen no tests using a 'field strength meter' or spectrum analyzer yet.

One of the most problematic aspects of 'noise issues' is that they are frequently not binary / black-and-white issues, but such issues are often marginal, variable, or intermittent as well. Something may appear to work today, but be degraded or fail to work completely the next, depending on variable factors which may not be evident. Additionally, if it's interfering with an RF AV (or other) equipment remote (just for example since there's one sitting here), or increasing the BER (bit error rate) on a wi-fi or BT connection in the vicinity, will you know it? How much do you depend on RF devices / products in your environment? Are you sure you want to sign up for worrying about all this at this point in time?

These are things I consider, and everyone has to make their own subjective decision about.
Interesting. I've only tried them in a couple flashlights so I haven't noticed any problems. But it's good to know
 

letschat7

Flashlight Enthusiast
Joined
Dec 7, 2022
Messages
2,624
Location
West Virginia, North America
XTAR 1.5 Li AA works fine for a couple years now in X-Box controller.
Any AA will work ok in that though. It is more interesting to see it used in something that's performance depends on the output of the cell or if it significantly extends run time.

The only advantage I'm finding with XTAR is no worries about leaks but other cells don't have issues either.

I sure wish they could drive a LedLenser or Coast light as having 1.5 instead of 1.2 volts would be so much better. If the lights could handle 1.7v I'd use lithium.
 
Top