Just curious, why do people try to avoid using full-sized C and D NiMH batteries?

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StorminMatt

Flashlight Enthusiast
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I can't help but notice that SO many people out there who have C and D lights will try to do anything possible to get around using full capacity C and D batteries in these lights. The usual solution is to simply get AA batteries and use them with adaptors. But compared to full capacity C and D batteries, capacity of AA batteries in adaptors is FAR less than a full-sized C or D. And given the cost of batteries and adaptors, it's little (if any) cheaper, especially in comparison to the overall capacity. Not to mention that adaptors are a failure point and add resistance to the batteries. Yet most people avoid real C and D batteries like the plague. I do know that many people probably don't have a charger that can handle C and D batteries. But this is not a major expense, especially compared to that TK70 that needs D batteries. Is there generally something bad about C and D NiMH batteries? Or do alot of people simply consider anything that's not an Eneloop to be worthless? I'm just curious.
 
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Well, a full size high capacity D NiMH is really heavy, a AA Eneloop in an adaptor is a lot lighter. A real high capacity D NiMH is also very expensive! I also only have cheap lantern that uses 2 D cells, so I really have no need for a "real" NiMH D. And they do make low self discharge D and C cells
Everyone here will have a different opinion, but that's just mine
 
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StorminMatt said:
I can't help but notice that SO many people out there who have C and D lights will try to do anything possible to get around using full capacity C and D batteries in these lights. The usual solution is to simply get AA batteries and use them with adaptors. But compared to full capacity C and D batteries, capacity of AA batteries in adaptors is FAR less than a full-sized C or D. And given the cost of batteries and adaptors, it's little (if any) cheaper, especially in comparison to the overall capacity. Not to mention that adaptors are a failure point and add resistance to the batteries. Yet most people avoid real C and D batteries like the plague. I do know that many people probably don't have a charger that can handle C and D batteries. But this is not a major expense, especially compared to that TK70 that needs D batteries. Is there generally something bad about C and D NiMH batteries? Or do alot of people simply consider anything that's not an Eneloop to be worthless? I'm just curious.
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maybe something to with ammperage?
 
AA batteries are so ubiquitous, inexpensive and easy to store/carry that a one-size-fits-all mentality has made them handy for covering all needs, especially now that there are adapters that allow them to operate items not initially designed for them.
 
Plus I'd have to get a dedicated charger because my favorite NiMH chargers are AA/AAA. More clutter.
 
StorminMatt said:
why do people try to avoid using full-sized C and D NiMH batteries?
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When higher voltage needed, using AA to D adapters help to keep size of flashlight easy to use.
You can get 9AA to 3D for 10.8 volt application while carrying a 9D flshlight will not make much of sence.
Another option is using different chemistry batteries such as lithium ion instead of full size NiMH.
 
my 2d maglight is now powered by 6 AA sanyo eneloop batteries. ROP maglight via some adapter i bought on here. Not too practical of a light since its 1 mode like 800 lumens and makes so much heat it can make paper smoke, but its kind of fun. It has a cammed reflector so i can go from massive flood to throw with a twist.

I wonder how it would work with 2d nimh, never thought of that
 
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I have two 6 D cell Maglights with TerraLux MiniStar 5s installed and I just keep regular Energizer/Duracells in them. They're at the sides of my bed and don't see much use, so sporting for a 12 pack every 5-10 years, is fine for me. I guess for me, the initial startup costs is what's preventing me from going the true D NiMH route. I have an older Energizer NiCad charger that would work, but ehhh...

Chris
 
Maha makes a LSD NiMH D-cell - the Imdeion NiMH D with a real 9500 mAh capacity. They are very good cells and have very good performance with decent (1-amp +) current drains. They're not cheap, but they work well.

Compare the price of them to Eneloops + Adapters, and it costs about the same in the end.

A separate charger? Yes.
Worth it? Yes, it is to me.
 
Shadowww said:
More like 8100 mAh real capacity.
http://www.datalucis.com/
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This is actually no better than the MUCH cheaper Tenergy Centura batteries. Not to mention that, if you go to this site, you will notice that the Centura DESTROYS this battery when it comes to internal resistance. In fact, even a size C Centura does better than the size D Imedion battery! After seeing this site, I would DEFINITELY steer clear of Imedion. Also, when it comes to Tenergy, the Centuras seem to be MUCH more solid performers (when it comes to living up to the numbers) than their Premium batteries. And this runs the whole range from AAA to D.
 
I think it's a question of size for the light. Even a C-sized light is quite a bit bigger than a comparable 18650 light. I also think the flashlight designers tend to like 'pocket rockets' and so do many people out there... Would you choose a 1xC cell light or a 1x16340 or 1x18650? In the end, I think the smaller lights make more sense as an EDC light for most people and 18650's have enough capacity, output and cheap enough that there's really no gain from the extra capacity in a C- or D-sized NiMH battery.

Having said that, there was a 2xC-sized light - think it was a Lumapower - that was pretty tempting as it allowed you to use 2xC-cells and also 1 cell in a pinch. Good over design but perhaps not quite as sexy as some of the smaller lights. If they put an XML U2 in a 2xC-sized, programmable light, variable output and at a decent price, perhaps more people would buy those instead of m&glites.

af0h said:
Maha makes a LSD NiMH D-cell - the Imdeion NiMH D with a real 9500 mAh capacity. They are very good cells and have very good performance with decent (1-amp +) current drains. They're not cheap, but they work well...
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I also picked up some rechargeable Imedion NiMH C- and D-sized cells for a couple of m&glites that had LED dropins... definitely increases the capacity!
 
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RGB_LED said:
I think it's a question of size for the light. Even a C-sized light is quite a bit bigger than a comparable 18650 light. I also think the flashlight designers tend to like 'pocket rockets' and so do many people out there... Would you choose a 1xC cell light or a 1x16340 or 1x18650? In the end, I think the smaller lights make more sense as an EDC light for most people and 18650's have enough capacity, output and cheap enough that there's really no gain from the extra capacity in a C- or D-sized NiMH battery.
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I guess the way I see things, the nemesis of 'pocket rockets' is low runtime. Even a single 18650 really can't run a decently powerful light on 'high' for a terribly long time compared to, say, 3C or 3D (or more). And, at least in situations where I want high light output for hours rather than minutes, a small light is pretty useless. Additionally, I feel like there is something to be said about a light with a nice, substantial feel (vs a 'pocket rocket'). There are certainly times when a larger light just feels better than a smaller one.
 
StorminMatt said:
I guess the way I see things, the nemesis of 'pocket rockets' is low runtime. Even a single 18650 really can't run a decently powerful light on 'high' for a terribly long time compared to, say, 3C or 3D (or more). And, at least in situations where I want high light output for hours rather than minutes, a small light is pretty useless. Additionally, I feel like there is something to be said about a light with a nice, substantial feel (vs a 'pocket rocket'). There are certainly times when a larger light just feels better than a smaller one.
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a D cell stores as much energy (in fact, even a bit less) than 18650, so they're pointless nowadays. 3x 18650 will have longer runtime than 3x D at same brightness, and that's with much lower volume, and much lighter weight.
 
A 18650 may eclipse a D-cell using different chemistry, but can you imagine D and C cells with the same lithium utilization and the runtimes you could get using them?
 
kaichu dento said:
A 18650 may eclipse a D-cell using different chemistry, but can you imagine D and C cells with the same lithium utilization and the runtimes you could get using them?
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Nobody manufactures high-capacity 26500 and/or 32600 cells though, because there is no market for them. 18650's are used in hundreds of millions in laptop battery packs, so there's that.
 
kaichu dento said:
A 18650 may eclipse a D-cell using different chemistry, but can you imagine D and C cells with the same lithium utilization and the runtimes you could get using them?
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Depends on what you mean by 'eclipse'. Li-ion batteries certainly have the advantage over NiMH when it comes to voltage. Simply put, it takes three NiMH batteries to give you what one Li-ion gives you in terms of voltage. A Li-ion is generally also lighter when it comes to stored energy per pound (although Li-ion doesn't have an advantage in terms of energy per volume vs NiMH). However, there are a couple of things to consider here (besides safety). First of all, equivalent sized Li-ion batteries are down when it comes to capacity. A 4000-5000 mAH 18650 is still most likely a cheap, Chinese battery that someone decided to put a big number on. 3000-4000 is MUCH more realistic. And even a D sized Li-ion battery (32500, I believe) doesn't have the capacity of an LSD NiMH D battery. Furthermore, although Li-ion does have the ability to produce significant current and has a MUCH more constant voltage output vs alkaline, NiMH still has it beat on these two counts.

Not to bash Li-ion batteries. They are still 'up and coming', and there are perhaps improvements to be made. But, although it has its advantages over NiMH (especially in regard to being able to produce higher voltages in a smaller package), it still isn't a completely superior technology, even if you ignore the safety aspects.
 
StorminMatt said:
And even a D sized Li-ion battery (32500, I believe) doesn't have the capacity of an LSD NiMH D battery. Furthermore, although Li-ion does have the ability to produce significant current and has a MUCH more constant voltage output vs alkaline, NiMH still has it beat on these two counts.
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Uhm.
Energy capacity is measured in Watt-hours, not Amp-hours.
a 18650-sized 3400mAh 3.6V Li-Ion has 3.6*3400 = 12240 mWh = 12.24 Wh of stored energy.
a 32600 (D)-sized 8500mAh 1.2V NiMH has 1.2*8500 = 10200 mWh = 10.2 Wh of stored energy.

That's with 18650 being ~5 times lighter than D NiMH, and having ~3 times smaller volume.

Speaking of significant current.. a IMR Li-Ion 26650 beats NiMH D hands down, while still having quite a bit smaller volume, and being MUCH ligher.

..not to mention that Li-Ion's are much easier to charge properly than NiMH's.
 
Shadowww said:
Nobody manufactures high-capacity 26500 and/or 32600 cells though, because there is no market for them. 18650's are used in hundreds of millions in laptop battery packs, so there's that.
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I guess you didn't understand my post since you replied with a point of common knowledge and followed with an unverifiable claim.

StorminMatt said:
Depends on what you mean by 'eclipse'.
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My point was simply to not compare unequal chemistry when comparing power sources. I think many think of D-cells in terms of alkaline and 18650 typically marketed in lithium aren't directly comparable on even terms.
Similar chemistry with a larger physical package would eclipse the smaller one. Whether it's preferable or not is another issue, and not one I care to pack with me on a daily basis!
 
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