# Rechargeable Li-Ion C and D cells



## PYKE (Dec 10, 2008)

I have a couple modded maglites that whenever I really need, the batteries are dead. I then have to resort to my less powerful Lithium lights(only less powerful as compared to my mods-I know there are some VERY powerful lithium lights out there...). I would really like to be able to have some rechargeable lithium batteries in my Mags so that they can still have their charge whne I need them...is this possible?


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## vestureofblood (Dec 10, 2008)

PYKE said:


> I have a couple modded maglites that whenever I really need, the batteries are dead. I then have to resort to my less powerful Lithium lights(only less powerful as compared to my mods-I know there are some VERY powerful lithium lights out there...). I would really like to be able to have some rechargeable lithium batteries in my Mags so that they can still have their charge whne I need them...is this possible?


 

Hello PYKE,

Rechargeable C cell li-ion available here on the market place. D cells are available from Kaidomain here. There are single D cells available and a 2xD cell pack. The 2xD pack sold in post #4 comes with a charger. I don't know how familiar you are with using li-ion cells but if you are not I STRONGLY recommend you read up on the safeties involved before purchasing. Also if you are uncertain about use it would be helpful to post what kind of mods you have on your light as li-ion cells run about 3.7 volts per cell and not the typical 1.5v alkaline cells do.


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## PYKE (Dec 10, 2008)

To be honest, the only thing I know about li-ion is the rechargeable 18V Hitachi tool kit I bought 2 years ago. I really like this technology of battery for the fact that my drill always have juice in it.
My main lights that I looking to power is a 3D Mag running on this Elektrolumens mod: http://elektrolumens.com/Mag-P7/Mag-P7.html
My other light is a modded 3X3W Luxeon LED Mag drop=in by a fellow forum member...not sure if this is enough info on the latter, but if not I could find out...
Thanks for the quick reply Vestureofblood!


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## jerry i h (Dec 10, 2008)

Wait: I am confused :thinking: (so what else is new?).
Rechargeable NiMH or NiCD are 1.2 volts; a Li-ion comes in at 3.7 volts (4.1-4.2 fresh off the charger). These are NOT interchangeable. So, if your M*g mod used NiMH, Li-ion is not an option. 
What exactly is your mod using right now for batts?


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## PYKE (Dec 10, 2008)

BTW, didn't I read somewhere that since 1996 the Li-Ion technology has become much safer? I've seen pics of exploded flashlights before so I steered cleard of lithium cells because the after effects reminded me of a pipe bomb....


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## PYKE (Dec 10, 2008)

Right now I'm running 3X3D Ni-Mh and 3X3C Ni-Mh in my lights....Lithium isn't a possibility? Not even with those 18650(If I remember correctly...)?


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## jerry i h (Dec 10, 2008)

The short answer is no. 
OTOH: one 18650 would take the place of ALL three D's or C's. You would need some sort of holder + spacer to hold the singe 18650 and take up the rest of the space normally occupied by the alkys/NiMH's. It can be done, but you need to be a modder (which I am not; if you ever seen me try to use hand tools, you would understand why). MDOCOD and FIVEMEGA can probably custom manufacture such a beastie. 
Then, you would have this custom holder + fully charged 18650 in storage ready to go at a moments notice. 
As for the safety of Li-ion: I am currently using AW's protected 18650, and I use it without fear or concern.


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## mdocod (Dec 10, 2008)

Forget about lithium-ion in your mags for the moment. Your experience with a lithium tool should not be considered useful for handling loose cells of a totally different chemistry than what is in that tool. Keep in mind that their are numerous lithium chemistry cells available, and they all get lumped into the category of "lithium-ion" which is EXTREMELY misleading and reckless by the industry in my opinion. The lithium ion cell in your laptop and cell phone are VERY different from the lithium-ion found in a tool. 

For 3 cell flashlights, in C and D size, your best bet is just to get low-self-discharge NIMH cells and call it a day. They will be direct replacements, with good capacity... Get these:
C cells
D cells


Out of curiosity, which NIMH C and D cells are you using currently? And what flashlights are they going in specifically? (I'm going to take a guess that you have some store bought cells with ~2500mAH capacity)....

I have CHEAP NIMH C and D cells from powerizer/tenergy. I top them up once every few months, but they have never let me down and always have a good chunk of juice remaining when I put them into service in power outages and stuff. This leads me to wonder what C and D cells you are using to have had such a bad experience, as most of the better C and D size NIMH cells out there, even the non-LSD cells, are pretty decent at retaining a charge in my experience.


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## vestureofblood (Dec 10, 2008)

PYKE said:


> To be honest, the only thing I know about li-ion is the rechargeable 18V Hitachi tool kit I bought 2 years ago. I really like this technology of battery for the fact that my drill always have juice in it.
> My main lights that I looking to power is a 3D Mag running on this Elektrolumens mod: http://elektrolumens.com/Mag-P7/Mag-P7.html
> My other light is a modded 3X3W Luxeon LED Mag drop=in by a fellow forum member...not sure if this is enough info on the latter, but if not I could find out...
> Thanks for the quick reply Vestureofblood!


 
Hey PYKE,

I am going to have to vote with Mdocod on this one. In order to run a P7 mag on li-ions you would either have to

A) cut it down to a smaller size.
B) install a driver board or
C) make a spacer to use only one cell.

In my opinion the easiest thing to do would be to get a quality set of NIMH C or D cells with a low self discharge. This will give you far greater capacity that trying to run on one 18650 or even one C cell li-ion. An AW 18650 averages about 2200mah and the C cells are 3300mah, where the Accupowers are rated at 4500 for C an 10k for D cell.


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## divine (Dec 10, 2008)

mAh isn't directly comparable when the voltage is different.

If you have 3 li-on C cells and wire them in parallel, you have essentially what three D nimh's in series are. Almost the same voltage, almost the same capacity.


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## 300winmag (Dec 10, 2008)

My setup is D size Accupower Evolution LSD batteries and the Maha 808ma charger, Works beautifully with my Malkoff triple drop in.


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## PYKE (Dec 11, 2008)

I'm using the same brand and type of batterry in both of themanasonic Pro+ 3000 mAh. 
WOW...those Accupower are 10 000 mAh!! I wasn't aware that batteries have gotten that far!


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## yellow (Dec 11, 2008)

1: *"protected"* Li-Ion cells --> *perfectly SAFE*
2: Input voltage from three Li-Ion cells = 12.6 Volts fresh from charger
when Led insert / Led mod accepts that Voltage --> *perfectly SAFE*
... why causing unnecessary confusion and fear? :thinking:

3: large three cell Mag (w. Li-Ions), if the user wants to tote it --> better than anything smaller because more power in cells


but of course "standard" low discharge cells are easier at the moment, being a direct replacement without any additional work
(they house less energy! Comparison with P7 driven at spec: 
* w. 3 Ni-Mh Ds (the ones linked above) --> about 3.5 hours
* w. 3 Li-Ion Ds (again: linked above) --> about 5.5 hours
PS: thats when calculating with the ratings given, I do not believe else the 10000 mAh of the Ni-Mh Ds and the 5000 mAs of the Li-Ion Ds


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## Bullet Bob (Dec 11, 2008)

I have two of Waynes p7 modded 3D mag lights and have had them now for almost a year. the accupower low discharge NIMH and a MAHA charger is the way to go and these lights ALWAYS have power. Recently the wife had to use one to look for one of her cats and was out in the woods for over an hour and the light which had been sitting for months ran perfectly with plenty of power after that. Thats your best bet for for those lights. You can get the batts from Thomas distributing.


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## mdocod (Dec 11, 2008)

PYKE said:


> I'm using the same brand and type of batterry in both of themanasonic Pro+ 3000 mAh.
> WOW...those Accupower are 10 000 mAh!! I wasn't aware that batteries have gotten that far!



AA cells can be found as high as ~2700mAH these days, but they suffer from severe self-discharge problems, the more conservative cells ~1800-2300mAH tend to be far better performers as far as retaining a charge and reliability is concerned. The LSD line of AA cells falls in around 2000mAH capacity.

Any "C" or "D" size cell, that isn't higher in capacity by a proportion large enough to justify it's larger size, is probably not a C or D cell at all. Most store-bought C and D size NIMH cells are ~2000-3000mAH capacity, and contain a much smaller cell inside of an empty can. The amazing thing is they often charge $10 or more per cell for a cell full of air. I hope you didn't get ripped that bad. 

The industry seems to do this because most of the chargers sold in stored do not have a charge rate fast enough to work well with a 10AH cell size. 20+ hour charge rates would make a store bought "quick-charger" seem pretty slow, so they can "speed up" their charge times by reducing the capacity of the cell. 

Eric


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