Unmodified Maglites on Li-Ions, any hope?

My end-game is to get rid of all of the battery recycle bags around our house and Li-Ions are the most practical technology to achieve that. I realize Maglite's market are normal people, not us. I'm just trying to determine if there is any way that a stock Maglite could ever be useful to me. Can you just buy a 3D LED, put a 32650 and a dowel wrapped in tinfoil to take up the slack, or replace an XL series 3AAA carrier with a ~22600? I read the XL battery contacts won't line up, but that's a minor detail to fix with a simple, flat circuit board. Are there bigger issues such as using a basically a dumb current regulation system that depends on the internal resistance of the batteries to limit the current?

Thanks!

Putting tinfoil in the place of two D-cell batteries seems not good to me, it would be better to use a plastic tube with metallic endcaps and a connecting wire between the endcaps You should the parts Aou need somewhere for free or cheap.

Erzengel said:

Putting tinfoil in the place of two D-cell batteries seems not good to me, it would be better to use a plastic tube with metallic endcaps and a connecting wire between the endcaps You should the parts Aou need somewhere for free or cheap.

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I'm suggesting the foil and electrical tape method guys commonly use for testing. I also know the method you are describing. However, if our time is worth anything that is also the most expensive. Before I would do that, I would look to see if I could use a standard fake battery(s) to take up the space. There is no way to cost-effectively compete with a fake battery that threads together at an invisible part of the label, that people use to hide things in.

I had good results with:

4-cell Mag bulb
2C or 2D mag (2C means you have to fool with the springs)
2x 18650 wrapped in several sheets of rolled paper & duct tape

You will need a small shim and a quarter behind the last battery to contact the spring. The 4-cell bulb is rated 4.8v, and overdriven to 8.4v is stupidly bright for about an hour. Then it burns out. The 6-cell (7.2v rated) bulb would last longer and be much brighter than stock, but more reasonably long-lived.


Edit; Many 3xAAA carriers with + on top and - on bottom can be replaced with an 18500 and a spacer. I have a few 3xAAA cheapies kicking around on LifePO4 cells. A Li-Co fresh off the charger might be too vigorous.

I use Low self discharge C NiMH. 2900 mAH to 4500 mAH depending on brand. The 2900 mAH Ray-O-vac ones lasted 1 hour in my P7 Mag. A stock Mag bulb only pulls 1/4 the current so should last 4 hours. 6 hours with the 4500 mAH version.

Low self discharge D NiMH are available from 2900 (sigh) to 10,000 mAH. Get the higher capacity ones and you don't need lithiums. (Your best 18650 is around 2900 mAH and 26650 around 4000 mAH) 3*10.000 mAH D NiMH is heavier than 1*26650 but has 2.5X the capacity.

LEDninja said:

I use Low self discharge C NiMH. 2900 mAH to 4500 mAH depending on brand. The 2900 mAH Ray-O-vac ones lasted 1 hour in my P7 Mag. A stock Mag bulb only pulls 1/4 the current so should last 4 hours. 6 hours with the 4500 mAH version. Low self discharge D NiMH are available from 2900 (sigh) to 10,000 mAH. Get the higher capacity ones and you don't need lithiums. (Your best 18650 is around 2900 mAH and 26650 around 4000 mAH) 3*10.000 mAH D NiMH is heavier than 1*26650 but has 2.5X the capacity.

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But does this work in the Maglite D size LED lights? If the LED regulation depends on cell resistance, the batteries used matters a lot.

IT_Architect said:

But does this work in the Maglite D size LED lights? If the LED regulation depends on cell resistance, the batteries used matters a lot.

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It's more than just cell resistance, it's also voltage under load, which varies by chemistry, cell size, and brand (in that order). If it's dumb regulation, then you're looking at a predictable thermal overload in the LED or the resistance path. If it's electronic regulation, then it's harder to guess what will kill it (sooner or later) and what will run just fine.

Yesterday I found an incan mag solitaire I had forgotten about.

10440 batteries work great in this light, but only for about 0.1 seconds

AnAppleSnail said:

It's more than just cell resistance, it's also voltage under load, which varies by chemistry, cell size, and brand (in that order). If it's dumb regulation, then you're looking at a predictable thermal overload in the LED or the resistance path. If it's electronic regulation, then it's harder to guess what will kill it (sooner or later) and what will run just fine.

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All true, and the point of the thread. So far, nobody knows. I'm just going to write of Mags. I'd guess if they did have any kind of intelligent regulation, they would have an LED version of their rechargeable.

There is actually the ML125 which is a NiMH rechargeable/alkaline unit. I'm not sure how different it is though circuitry wise since it includes the smart switch and other circuitry. Personally though, I have run a 3D MagLED on the AA lithium Energizer primaries (LiFeS2 chemistry) and on the Eneloops and haven't had any issues crop up. The MagLED I have is the first version with the drop in module with the Luxeon III and it is still going strong after these years of use. From the day I pulled it from the box until a year ago, I ran it exclusively with the LiFeS2 primaries. As of late though, I switched to Eneloops. Of course, this doesn't tell you that this is the case with all other MagLEDs, and I am not intimately acquainted with the circuitry of the newer MagLED lights.