What voltage does a Maglite 5 cell bulb flash?

[Chicken Drumstick]

Anyone know how many volts one of these can take?

Maglite 5 cell Xenon bi-pin bulb

Will it safely run on 2 x Li-ion (aka 8.4v resting).

I've run the 6 cell bulb on 2 x Li-ion and it is ok. But 6 x 1.5v should be 9v, so 2S Li-ion is a tad low. 7 x Eneloop has a higher resting voltage than the 2S li-ion and on the lightbox does also out lumen the Li-ion with the 6 cell bulb. But for this application I can't run Eneloops. So it is 2S Li-ion only and I'm trying to decide if a 6 cell or 5 cell bulb would give the best performance.

Don't really want to buy the 5 cell just to instaflash it.

Unless anyone can point me at any other bulbs. I know of the TL-3 bulb, but haven't been able to find any. And I'd need sensible shipping to the UK too.

 

[alpg88]

Nope, bad idea. 5 cells with flash on 2x li ion

 

[Olumin]

You have to take the cell voltage under load. roughly 1.2V for alkaline & 3.7V for li-ion. If you take that into account a 6 cell bulb will only be overdriven by .2 volts on batteries fresh from the charger. A 5 cell bulb by 1.4V. Probably a flash, but haven't tried it.

6 cell bulb works very well on liions. FM sells his G4 adapter in which you can run 6V halogens that will take 2x lions without flashing, at least the 10W ones.

 

[alpg88]

Just do not try 6v halogen with stock plastic reflector, you'll destroy it.

 

[Chicken Drumstick]

Nope, bad idea. 5 cells with flash on 2x li ion

Is this from experience or just a guess?

 

[Chicken Drumstick]

You have to take the cell voltage under load. roughly 1.2V for alkaline & 3.7V for li-ion. If you take that into account a 6 cell bulb will only be overdriven by .2 volts on batteries fresh from the charger. A 5 cell bulb by 1.4V. Probably a flash, but haven't tried it.

6 cell bulb works very well on liions. FM sells his G4 adapter in which you can run 6V halogens that will take 2x lions without flashing, at least the 10W ones.

Thanks. Don't think FM has any G4 adapters and wouldn't work on this light anyway. Also the bulbs he sells aren't suitable to ship to the UK without spending silly money on them. Which I won't be doing.

Yep aware of nominal voltage. Hence asking the question. I found the 6 cell bulb somewhat underwhelming on 2S Li-ion. Was hoping I could maybe drive the 5 cell one a little harder, but hoped for a definitive answer from someone who had tried, rather than throwing money down the toilet if it was never going to work.

I'd also guess bulbs are rated using a power supply unit rather than batteries of various states. Therefore I'd expect 5 cell to handle 1.5v x 5 = which is 7.5v as a part of being "within" spec. The question then becomes how much can it handle above and beyond its rated spec.

I know the 6 cell bulb will instaflash on 8 fresh Eneloops. But will run on 8 partly used Eneloops. 7 Eneloops is the safe space on this bulb. My 7 cell "pack" is currently reading 8.96v (1.28v each). Freshly charged I think it is nearer to 9.6v

Using this logic 9.6v / 7 is 1.37v each. I'd assume you could run 6 cells on the 5 cell bulb. Which would be 1.37 x 6 = 8.23v. Not a million miles from the static 8.4v of Li-ion and only then if you have them charged to 4.2v, many Li-ion chargers will terminate between 4.14 & 4.18v.

Just musing at the moment. Need to see if the torch actually turns up first.

 

[alpg88]

Is this from experience or just a guess?

LOL, from experience of course, with fresh cells. tried in my ROP mag, i flashed dozens of bulbs experimenting, i can tell you what not to do with great certainty,
However it may work with half drained cells, but it would defeat the purpose.

 

[bykfixer]

I have some 1 amp 18650 batteries by Nuon that did not murder a 5 cell Mag bi-pin when I first tried it in a 3 cell ML25IT, but chose the TL3 bulb in it because it has a lot less filament shadow. The 18650's that would have enough oomph for an ROP light would zap the 5 cell bulb quickly.
Another thing I do is let the Nuons set over night before using them. I read here a while back letting batteries rest for a little while helps the over driven bulb last longer.

 

[alpg88]

i used sony vtc5 18650 that pulled out from power tool battery, in my ROP, i once accidentally shorted one with a nickel strip, it got bright yellow in seconds, those are no joke.

 

[Chicken Drumstick]

LOL, from experience of course, with fresh cells. tried in my ROP mag, i flashed dozens of bulbs experimenting, i can tell you what not to do with great certainty,
However it may work with half drained cells, but it would defeat the purpose.

Great, well not for the bulb! But thanks for confirming. That is exactly the sort of info I was wanting to know.

 

[Chicken Drumstick]

I have some 1 amp 18650 batteries by Nuon that did not murder a 5 cell Mag bi-pin when I first tried it in a 3 cell ML25IT, but chose the TL3 bulb in it because it has a lot less filament shadow. The 18650's that would have enough oomph for an ROP light would zap the 5 cell bulb quickly.
Another thing I do is let the Nuons set over night before using them. I read here a while back letting batteries rest for a little while helps the over driven bulb last longer.

Shouldn't really make any odds with Li-ion, they don't really "settle" or self discharge. Not in a few hours to a couple of days at least. Not by any noteworthy amount.

Not heard of 1amp 18650's before.

 

[bykfixer]

Nuon 3.6V 18650 Lithium Ion Rechargeable Battery - NURE18650-1

This 18650 rechargeable lithium ion battery is designed only for use in rechargeable lithium ion flashlights. Includes protection circuitry to ensure safe use.

www.batteriesplus.com