He's saying the battery has no real current capacity. They're designed for things like CMOS memory backup, not proper power draws.
Taking apart a recalcitrant 3 D cell Maglite
- Thread starter TD-Horne
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Sjvalleydave
Newly Enlightened
What kind of CDR do you need in the flashlights. I saw that the CDR is low, but a big capacity 19Ah...
chillinn
Flashlight Enthusiast
What is "CDR?"
Sjvalleydave
Newly Enlightened
Continous Discharge Rate
chillinn
Flashlight Enthusiast
"Continuous discharge rate" is arbitrary and variable, calculated by dividing a cell's capacity in Ah by the hours it takes to deplete it. CDR, as you say, is whatever current load that is put on a cell, which can be literally anything, 0.2A, 0.5A, 1A, 3A, etc. The attachment you posted used "nominal discharge current," which is not a standard term. What marketing meant (I assumed) and what matters, because it tells us the amp rating of the cell, is known as maximum continuous discharge current. But it is possible, I suppose, that "nominal discharge current" is the current the manufacturer used to calculate the advertised capacity (which would indeed be CDR in that case). The smaller the current, the larger the capacity, so it is a trick used by a lot of cell labels to claim high capacity when, in fact, at the currents used by flashlights, that published capacity is a gross exaggeration if not outright deception.
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TD-Horne
Newly Enlightened
What those cells cannot do, according to previous answers to my own questions, is to produce enough current for the LED to function. The 4 mA is not enough.
Tom Horne
We use lithium thionyl chloride batteries extensively at work for PLC memory retention, and that's where they're best to stay.
I've used 3AA-D parallel adapters in my D cell alarm system and I can say a good Procell Constant cell with near on 20k mAh capacity lasts well over twice as long as 3AA as you would expect. Where adapters work well is in series - in my vehicle's 2D Mags, I use them with 6x L91 and high power drop ins. Get around 10v in a lightweight, no leak package. Store D cells in a case incase long runtime is required.
I've used 3AA-D parallel adapters in my D cell alarm system and I can say a good Procell Constant cell with near on 20k mAh capacity lasts well over twice as long as 3AA as you would expect. Where adapters work well is in series - in my vehicle's 2D Mags, I use them with 6x L91 and high power drop ins. Get around 10v in a lightweight, no leak package. Store D cells in a case incase long runtime is required.
That's interesting as my L91s measure 1.7-1.8v but haven't ever flashed my minimag bulbs, just give a nice white light.
I run an edc ML25LT exclusively on them. It's perfectly safe as Maglite themselves now sell a mag charger powerbank li-ion 18650 battery for use with the ML series 2 cell (4.2v max)
Did you ever get the light apart TD?
That's just painful to look at.☹️
IMA SOL MAN
Flashlight Enthusiast
Ooooooo, that looks like a very old ROV carbon zinc cell! How old would you say the Maglite was?
That was a Kel-Lite from about 1972. Wouldn't surprise me if the batteries were contemporary.
TD-Horne
Newly Enlightened
No I abandoned that effort when I couldn't get the switch to move down enough to extract the stop ring. I took a tub wrench of the right size and a lineman's 2# pole hardware hammer to it. It didn't budge. I may resort to a huge bit and my son's drill press. Once the switch is out of the way I could use a hacksaw to cut out the cylindrical remains by putting the blade inside the bored hole and reassembling the blade onto the handle. That is a lot of work but I can be kind of a stubborn fella on something like this. I do hate throwing salvageable stuff away.
I like the attitude, but keep in mind you could probably get close to a half dozen Mags with cosmetic issues off eBay for less than a replacement switch would cost. Unless there's something unique about it it's one of tens of millions made.
Sometimes when something seems like it can't be done it's time for "oh yeah, watch this" to take place.
TD-Horne
Newly Enlightened
Has anyone tried applying a heat gun to the tube to get it to expand enough to move the batteries away from the switch? If a heat gun would be too hot I have a hair dryer I used to use as a dummy load before I retired out of working in the electrical craft.
Tom Horne
Tom Horne
swampgator
Enlightened
Those won't even light a 2D cell bulb
That hurts me..
Bad enough for a Maglite to die by alkaline leakage but a Kel-Lite dying to leakage should be criminal..
IMA SOL MAN
Flashlight Enthusiast
Inmate 1: What are you in for?
Inmate 2: I let some alkaline batteries leak in a Kel-Lite flashlight.
Inmate 1: You gotta be joking. Really, what are you in for?
Inmate 2: Seriously! I'm in for allowing some alkaline batteries leak in a Kel-Lite flashlight! Can you imagine getting time for that? It seems somebody on a flashlight forum contacted a politician, and got it made a crime! Now I'm doin' time! When I get out, I'm gonna find that forum person, and I'm gonna...
Inmate 2: What are you in for?
Inmate 1: Industrial espionage. I stole some flashlight plans from this guy, uh, I'll just call him "PK". Sold 'em to some Chinese guy. Who knew the feds was watchin'?
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