LED Lenser p7 Questions

[Benno]

Hi everyone. I recently bought an LED Lenser P7 flashlight. I have a few questions which I'm hoping someone can answer, keeping in mind this is my first ever 'expensive' flashlight, and I'm totally new to this:twothumbs.

1) Will the flashlight be just as bright with NiMH's and Alkalines?

2) Is it possible to use rechargeable NiMH's in the P7?

I'm sure I'll think of some more questions as we go...

Thanks.

 

[Mr Floppy]

1) I use NiMH batteries. Its brighter for longer. Initially alkalines are brighter but it doesnt take long before they dim. (You wont really notice the initial difference anyway)

2) Yes. Its not a question I asked when I got my P7. I didnt see anywhere in the instructions that said not to use NiMH or alkalines exclusively. Then again, I didnt get any english instructions in my box.

:welcome:

 

[germanium]

Initial brightness will be slightly brighter with alkaline but that goes away very quickly (within 2 minutes). Beyond that the NIMH is brighter & lasts much longer at near full brightness. Bear in mind that for the first quarter hour you would not be able to see the difference in side by side comparison. beyond that you probably would see it though. This is one area that you should ignore the manufacturers recomendation on.

Lithium AAA's last the longest with the highest brightness of all but may stress the internal componants in a way that will shorten thier life as it will be in a constant overdriven state for a long period of time. NIMH batteries will not do that.

 

[Kilovolt]

Actually instructions do say not to use rechargeable batteries because of 'different electrical values'.

In any case I understood that it means not to use rechargeable batteries with a voltage higher than the alkalines (1.5V) so NiMH's (1.2V) should be allright. I use them in my P7 without any problem.

Were they thinking of 10440 Li-ion's when saying 'no rechargeables' ? :thinking:

 

[shadowjk]

Remember that alkaline and nimh volts aren't measured the same way. Alkaline starts off at 1.5V but quickly drops, especially under any kind of load, like a flashlight. Alkaline probably goes below 1.2V rather quickly in that light. Nimh on the other hand will be providing more volts for longer under load... Some lights are designed for the weak performance of alkaline, and might not cope with the higher performance of nimh. Personally I wouldn't worry though.

 

[germanium]

Remember that alkaline and nimh volts aren't measured the same way. Alkaline starts off at 1.5V but quickly drops, especially under any kind of load, like a flashlight. Alkaline probably goes below 1.2V rather quickly in that light. Nimh on the other hand will be providing more volts for longer under load... Some lights are designed for the weak performance of alkaline, and might not cope with the higher performance of nimh. Personally I wouldn't worry though.

It is really not a problem in this case. The LED will be better driven by NIMH but not overdriven. Lithium batteries on the other hand will overdrive the LED so avoid these if you want you light to last for years.

 

[Marduke]

It is really not a problem in this case. The LED will be better driven by NIMH but not overdriven. Lithium batteries on the other hand will overdrive the LED so avoid these if you want you light to last for years.

Many direct drive lights (ie nearly all LED Lenser) count on the higher internal resistance of alkaline cells. NiMH have a lower internal resistance, and therefore often overdrive a direct drive light whose poor design relies on alkalines.

 

[germanium]

Many direct drive lights (ie nearly all LED Lenser) count on the higher internal resistance of alkaline cells. NiMH have a lower internal resistance, and therefore often overdrive a direct drive light whose poor design relies on alkalines.

Not having any problems here with NIMH. Even with the resister in the tail bypassed in high mode it still runs cooler than some of my other lights that run 4 watt luxeons (Inova T3 & T4). I also still get really good run times. Evidence that it is not woefully overdriven. Most people are not going to bypass the tail resister & the light will hardly even get luke warm with the resister intact with NIMH batteries.

LED Lensers claim is that the light would niether be as bright or last as long with rechargables. Both these assertions have been totally proven wrong in some of the run time graphs I've seen.

 

[Marduke]

Evidence that it is not woefully overdriven.

LED Lensers claim is that the light would niether be as bright or last as long with rechargables. Both these assertions have been totally proven wrong in some of the run time graphs I've seen.

Evidence that it does not have proper heatsinking to conduct the heat to the exterior of the light. A light SHOULD get warm on such a high mode. If it doesn't, it has major issues.

LL makes a lot of claims. I have yet to see one that is accurate in any way, shape, or form.

 

[Mr Floppy]

Well, I found some english instructions in my box for the P7 (they were on the reverse side of the german ones )

It says this under batteries:

Never try to recharge batteries or use fresh and used batteries together. Always change all batteries at the same time and use high quality batteries and the same type only. Because of different electrical values the use of accumulators and high current batteries is not allowed. If you intend to not use this lamp for a longer time, take the batteries out to prevent damage by leaking batteries. Discharged batteries must be taken out. Used batteries and accumulators are hazardous waste and must be disposed according to the national legislation

I've highlighted the bit which I think might cause some debate. I have no idea what an accumulator is. Something lost in translation perhaps? I could transcribe the german if that helps?

Personally, I've been using NiMH in these pretty much from the day I got it. I've used alkalines a couple of times when I dont have a recharger with me. I personally haven't seen any ill effects of using NiMH batteries but I've only had this thing a few months. I have been using it pretty much as my EDC though.

 

[shadowjk]

accumulator = rechargeable battery

 

[Art]

Evidence that it does not have proper heatsinking to conduct the heat to the exterior of the light. A light SHOULD get warm on such a high mode. If it doesn't, it has major issues.

LL makes a lot of claims. I have yet to see one that is accurate in any way, shape, or form.

Can you explain this?
I actually like the fact that I can use the P7 for very long and it doesnt have any heat in it. Last weekend I had to use it on max for 2h nearlly continuos and the light was cool as it was turned off.

I use 1000mah nimh and it is great , the alkalines dont last very long and after 1h you end up with two modes with same power

Regards

 

[Marduke]

Can you explain this?
I actually like the fact that I can use the P7 for very long and it doesnt have any heat in it. Last weekend I had to use it on max for 2h nearlly continuos and the light was cool as it was turned off.

I use 1000mah nimh and it is great , the alkalines dont last very long and after 1h you end up with two modes with same power

Regards

If a high output light doesn't get warm on the outside, that means the heat is building up inside and is not able to find a thermal path to the exterior of the light. Essentially, it is cooking the LED.

 

[Art]

If a high output light doesn't get warm on the outside, that means the heat is building up inside and is not able to find a thermal path to the exterior of the light. Essentially, it is cooking the LED.

That is one of the first things I saw LL claiming as their optimum thermal dissipation ... but since you here don´t like any of their claims never mind...

http://www.ledlenserusa.com/technology.php just click in thermal management
Or is this just another bad publicity part?
Can´t it just be that the LL are actually heating up less then the others? :thinking:

 

[Marduke]

That is one of the first things I saw LL claiming as their optimum thermal dissipation ... but since you here don´t like any of their claims never mind...

http://www.ledlenserusa.com/technology.php just click in thermal management
Or is this just another bad publicity part?
Can´t it just be that the LL are actually heating up less then the others? :thinking:

Thermal management = heatsink. In the past LL hasn't used a sufficient one. If the did now (which would be a big improvement), the heat would be transferred to the light exterior. An internal heatsink which does not get rid of the heat is nearly as pointless as having no heatsink at all to begin with.

As for their marketing, take it with a grain of salt. Their "patented electronics" for example equals "direct drive with a drop resistor " in their advertising language.

 

[JBorneu]

So, Marduke, you are basically saying that the heatsink on the Malkoff M60L modules must be pointless because they are desinged to run in a polymer light without cooking the LED?

 

[Marduke]

So, Marduke, you are basically saying that the heatsink on the Malkoff M60L modules must be pointless because they are desinged to run in a polymer light without cooking the LED?

It's best ran in the 6P or G2 with aluminum head, or the G2 Nitrolon for shorter times. However, he does provide enough material there so there won't be any permanent damage.

But yes, the G2 Nitrolon is not a good candidate for high output LED's because of the inability to shed heat. It's a shortfall of the light, not the dropins. Malkoff did the best he could in the space allotted, and it's a better design than what anyone else has come up with.

 

[Swedpat]

1) I use NiMH batteries. Its brighter for longer. Initially alkalines are brighter but it doesnt take long before they dim. (You wont really notice the initial difference anyway)

2) Yes. Its not a question I asked when I got my P7. I didnt see anywhere in the instructions that said not to use NiMH or alkalines exclusively. Then again, I didnt get any english instructions in my box.

:welcome:

Initial brightness will be slightly brighter with alkaline but that goes away very quickly (within 2 minutes). Beyond that the NIMH is brighter & lasts much longer at near full brightness. Bear in mind that for the first quarter hour you would not be able to see the difference in side by side comparison. beyond that you probably would see it though. This is one area that you should ignore the manufacturers recomendation on.

Lithium AAA's last the longest with the highest brightness of all but may stress the internal componants in a way that will shorten thier life as it will be in a constant overdriven state for a long period of time. NIMH batteries will not do that.

I can confirm this. Some years ago when Maglite came out with their LED-versions I considered to buy a 2 or 3AA Mini LED Maglite. Then the salesman adviced me to get the Ledlenser 3AAA Quadrat light instead, which I did. I was quite impressed about this little light which was brighter than my Maglite 2D. Soon I noticed that the brightness decread pretty fast from the start with fresh batteries, and I needed to replace the alkalines frequently to hold the brightness. (as with usual crypton-bulbs and alkalines)

I still have the Ledlenser in my own but have placed 1000mAh NiMh cells instead. The difference is substantial; Even after hours I am hardly aware of a brightness fall. Regulation is a good idea, but not very necessary when using NiMh batteries I think, because the output is very even.

Regards, Patric

 

[jupello]

Since there seems to be so much debate on the heatsinking of P7, here's a picture of it:

(Picture taken from here ..there's also NIMH vs. alkaline runtime graphs if someone's interested)

To me that looks pretty ok..I would have made the center piece where the led is sitting little bit thicker tho.

 

[SureAddicted]

Marduke, do you own any LL lights?