LONGEST RUNTIME --- 200 to 600+ Hours from 30 to 80+ Lumens ???

My workplace frequently requires me to work in dark rooms, and I'm trying to find something that I can run for months at a time without having to worry about batteries.

I want....

- At least 200 hours of output all together (perhaps 7 hours a day?).
- At least 30 lumens, but I know that I'd be happy with 72 lumens, as my EDC light is a 2nd gen Pelican 1910 with that same output on high.
- Bigger and cheaper is likely better, as I'll be tossing this in a work toolbox, and won't be disappointed if it breaks.

I was considering a 6v Rayovac 10x LED Floating Lantern for $5, and adding a ~$10 4xD-cell adapter to replace the 6V batt... but 4x D-cells in rechargeables is gonna be fairly expensive if it's stolen and I have to get 4 more. I also don't think I have a D-cell charger, and even if I did manage to find one... it's likely very old and definitely doesn't recharge 4 cells at once.

So I'm thinking a 1x D-cell, or 1x C-cell, maybe, would be a good starting point. The CountyComm TLL comes in an older D-cell version and a newer C-cell version. I like the domed lens, as I will likely be tailstanding on the floor or hanging from something on the ceiling (it has threads to screw on to a stud, and there are plenty of 3/8" threaded studs at my work; I could likely find/make an adapter that would allow me to screw this light onto those 3/8" studs which would be pretty sweet).

But I'm most definitely open to Li-Ion batteries 18650 and larger... 25500, 25650, 32600, 32650, etc.

TLDR: Hundreds of hours of runtime from [domed] light putting out 30 to 100 lumen. Size, price, and other features are all up for debate, depending on other trade-offs.

Malkoff md2 running a m61LL 100 lumens for 10 hours is what I use for work purposes i have never needed more light with this set up Plus the high low ring inside the head will allow you to go into low power mode of im guessing 20 or so lumens for up close chores

That's not even close to what I'm looking for.

That 6v Rayovac 10x LED Floating Lantern for $5 + a ~$10 4x D-cell adapter to replace the 6V batt should get 45 hours stock... with the adapter and 4x D-cells.... it should be VERY easy to get 2x to 3x the Amp-hour capacity.

So we're talking 85 Lumens for 45 hours stock. With 4x D-cell adapter, we're talking 85 Lumens for 90 to 135 hours, no problem. Buying even the BEST rechargeable Ds, a new D-cell charger, etc. should still keep my total under $100.

Perhaps my new goal should be 100+ hours of runtime from ~80 lumens of light?? Anything compete with that? I'm assuming I'll have to live without a regulated light, but that's fine with me. If I could actually get 100 regulated hours of 80 lumen, I'd be VERY happy.

If it were me, trying to keep costs down and efficiency up, I'd go 6x18650's (protected 18650GA or similar in parallel), a $3 regulated buck driver, and a Nichia 219c LED with a $.50 switch. That should go about 80 lumens for about 100 hours, regulated 175 mA at about 2.8V to the LED. The adventuresportflashlight video showing a homemade diffuser with a plastic container would work great, though a higher quality diffuser would show off the led better. Light would be less than $10 materials; want more runtime, add more cells (but buy and use/charge in matched sets). Even the cheapest drivers would allow tweaking of brightness. Mounting in a little pelican case would make it water- and toolbox-proof.

By the way, I'm a little skeptical about 85 lumens for over 100 hours with 4xD cells. I'm thinking it might qualify for the ANSI standard, but spend most of that time at well below 50 lumens.

I have a feeling a soda can light will probably be the winner here; I know the old Zebralight S6330 would do 24 lumens for 192 hours, that was a few years ago..

These from Brightstar might work great for you

Bright star worksafe 2206 Led lantern 4 D cells 90 lumens 150 hours
" " " 2224 led flashlight 3 D cells 50 lumens 250 hours
" " " 2217 led flashlight 2 D cells 50 lumens 200 hours

all are industrial intrinsically safe led lights. the lantern runs about 45$ and the flashlights run 20$

Keitho said:

If it were me, trying to keep costs down and efficiency up, I'd go 6x18650's (protected 18650GA or similar in parallel), a $3 regulated buck driver, and a Nichia 219c LED with a $.50 switch. That should go about 80 lumens for about 100 hours, regulated 175 mA at about 2.8V to the LED. The adventuresportflashlight video showing a homemade diffuser with a plastic container would work great, though a higher quality diffuser would show off the led better. Light would be less than $10 materials; want more runtime, add more cells (but buy and use/charge in matched sets). Even the cheapest drivers would allow tweaking of brightness. Mounting in a little pelican case would make it water- and toolbox-proof.

Click to expand...

This thread inspired me--I couldn't stop thinking about a little custom multi-cell mule and charger that would run for long durations, so I put my money where my mouth is and just ordered the parts for a light described above from mtn-electronics: about $10 of parts that I don't already have on hand. I'll update this thread with the build details and see what I can come up with.

My old incan Maglite 2D with Dorcy 30 Lumen drop in will do 100hrs easy.

The new generation Maglite ML300L 3D has a great runtime. When it's on low power mode it's even better, and if you use high-capacity rechargeables it'll go even further. From the manufacturers website: High Output Runtime - 16h, Low Output Runtime - 77h, Eco Output - 117h. And that's just using normal alkaline disposables. Decent rechargeable cells like the Vapextech (10,000mAh) will get you far far far more. Alternatively, you could get LSD (Low Self Discharge) batteries which hold their charge for months and months (unlike normal rechargeables which'd slowly self deplete when on standby) so it's always ready to go. I'd suggest the Vapextech Instant 8000mAh D-Cell would be a good choice.

And you said you'd like something big and cheap. This is that, and is very robust too. Plus, if you ever need more power you can temporarily stick it on high power (625 lumen), and as its got a focusing lens, you can use it at longer range (up to 400 metres) when required or keep it on flood beam.

Look online and the torch can be had for as low as $35, then just add rechargeables (another $20 or so for decent ones) and a charger ($15).

Made in the USA, available off the shelf. Super simple, and it'll more than do what you need.

I just bought a Coast Polysteel 600 4AA flashlight with adjustable focus this weekend in a combo pack for $20 at the Terre Haute, IN Sam's Club. Online at Sam's, this combo is $29.99 (+ 10% for non-members).

The 73 lumen low is rated at 40 hours.

The high output of 710 lumens is rated at 2h 15min.

Partial press for momentary operation. Click for continuous.

H-M-L mode sequence is operated by partial presses of the tail switch until the output level you seek is present, then hold there for momentary or full click for continuous output.

Also available at the Home Depot online and there are reviews and answered questions there.

My local Sam's doesn't have this combination. I couldn't pass this combination up for $20 when I saw it at the Terre Haute store. I paid nearly $30 for the headlamp alone this time last year. I really like the adjustable focus.