Maglite and NiMh battereis

[Rodion]

I've read somewhere Maglite doesn't "recommend" using anything but Alkalines in its flashlights. Is there a particular reason for that? I'm kind of allergic to disposables. 

[NutSAK]

There shouldn't be any drawback to using NiMH, other than a slightly lower voltage, which might lower initial brightness slightly.  IMO, the extra runtime gained by using NiMH over alkaline would greatly outweigh any reduction in output.

[jock1]

I have used NiMH batteries in my mini mag for ages with no ill effects

[Rodion]

Well, I finally got the seemingly obvious idea of asking Maglite itself. Here's the asnwer (I asked about 10 hours ago. These guys are good.)

Rodian[cringe]:

We do not recommend the use of rechargeable batteries in standard or LED/ Maglites® because rechargeable batteries are rated at 1.2 volts, whereas standard batteries are rated at 1.5 volts. By using rechargeable batteries you loose .3 volts per battery, which means you will have less light output or a dimmer light. Another reason is because the discharge curve on rechargeable batteries stays at a higher voltage longer than standard batteries so the lamp/LED life is less.
If you can live with this go for it, it will not damge the light.

Don

As one can see, NutSAK was spot on. 

[Teofilo]

Well, I finally got the seemingly obvious idea of asking Maglite itself. Here's the asnwer (I asked about 10 hours ago. These guys are good.)

Rodian[cringe]:

We do not recommend the use of rechargeable batteries in standard or LED/ Maglites® because rechargeable batteries are rated at 1.2 volts, whereas standard batteries are rated at 1.5 volts. By using rechargeable batteries you loose .3 volts per battery, which means you will have less light output or a dimmer light. Another reason is because the discharge curve on rechargeable batteries stays at a higher voltage longer than standard batteries so the lamp/LED life is less.
If you can live with this go for it, it will not damge the light.

If that's the case, Rodion, I'll discontinue my plan of having a RCR for my Tk10 and P2D. Rechargeables are good in digicams and other remote operated stuffs, that has a mechanism where power from rechargeable batteries are burned. But on flashlights,... where power is burned directly by the lamp or LED, it will somehow,  damage our lights not at this time... but in the long run.  If I have a SureFire Invictus, I'll not gamble it on rechargeables!

[jzmtl]

Well it doesn't quite work like that. The power from battery isn't directly send to LED, a circuit controls how much power is supplied to LED so rechargeable or not doesn't matter if the circuit is designed to accept them (TK10 is, p2d isn't).

[Teofilo]

Yes  I Know there's a circuit controlling power to the bulb (LED), but RCR's have 3.6 volts against the standard 3 volts. Assuming the circuit of the Tk10 can handle 7.2 volts or more, how long do you think can the circuit or the LED withstand the inflow of voltage? I'm sure runtime/s will be affected in actual use. As advertise by Fenix, the Tk10, on turbo mode, using the standard 3v lithium, should only be use for 10 minutes. I'm not sure if it's the same using RCR's.

[NutSAK]

Even if slightly overdriven, a typical high flux LED will give you about 50,000 hours of life.  That is about SIX YEARS of constant runtime.

Do you think you'll ever own a flashlight long enough to run it for six years?  I won't.

[NutSAK]

Another reason is because the discharge curve on rechargeable batteries stays at a higher voltage longer than standard batteries so the lamp/LED life is less.

This is irrational thinking, IMO.

[jzmtl]

Yes  I Know there's a circuit controlling power to the bulb (LED), but RCR's have 3.6 volts against the standard 3 volts. Assuming the circuit of the Tk10 can handle 7.2 volts or more, how long do you think can the circuit or the LED withstand the inflow of voltage? I'm sure runtime/s will be affected in actual use. As advertise by Fenix, the Tk10, on turbo mode, using the standard 3v lithium, should only be use for 10 minutes. I'm not sure if it's the same using RCR's.

The circuit will send the same power to LED regardless of input voltage, assuming input voltage is within designed spec of the circuit. The 10 minutes warning as far as I know only present on P3D and it's more to do with heatsinking than battery used.

Another reason is because the discharge curve on rechargeable batteries stays at a higher voltage longer than standard batteries so the lamp/LED life is less.

This is irrational thinking, IMO.

Consider the heatsinking in stock magled is absolute piece of junk and the circuit needs to cut power in half within minutes of startup so it doesn't fry, I suppose it makes sense in a stupid way.

[EM745]

Another reason is because the discharge curve on rechargeable batteries stays at a higher voltage longer than standard batteries so the lamp/LED life is less.

This is irrational thinking, IMO.

Irrational? STUPID is more like it. It's almost like they're admitting that Mags are junk. 

To the OP, go ahead and use NiMH rechargeables. No worries.

With regards to 3.6V lithium rechargeables and Fenix lights... They're okay to use on P3D (or equivalent) lights (the P3D's driver is designed for a maximum input of 9V, I believe). It's not recommended to use them in the P2D lights, as the driver board is different than the one used in the P3D.

[Teofilo]

Very informative