Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.25 volt NiMH?

Hi: I have a new Fenix TK-41 coming and I want to be ready with spare batteries when it comes.I notice that the disposable AA Alkalines are 1.5 volts and the rechargable NiMh AA's are 1.25 volts.Would the higher voltage alkaline battery give me an overall better or stronger beam??
I also notice that the Fenix TK-41 comes with 8 Eneloop AA Nimh,which are 1.25 volts.
Being the total newbie I am,I thought all AA's were 1.5 volts!
Is it better to use the Nimh AA's at 1.25 volts because they have a higher capacity(mAH) than the 1.5 volt Alkalines and will a .25 volt more per Alkaline AA battery make a noticeable difference in light output? Thanks,Hot Brass

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

Use the NiMH. Here are some useful details:

1. All batteries suffer some voltage drop when you draw current from them. Alkaline AAs suffer TERRIBLY when you try to get more than about half an amp out of them, and drop below 1.0v per cell at high drain.

2. NiMHs of decent quality ($20 for eneloops) will last you about 1000+ charge cycles, compared to $20 of alkalines.

3. Most AA-powered lights are brighter with longer runtimes on the bright modes than on alkalines.

4. Many lights are regulated so that there is little difference in brightness within the range of the driving electronics. This is especially the case for lights with more than 3v of batteries.

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

+1 on the NiMH

Another good reason : alkalines can leak and damage your flashlight; I've never had a NiMH leak.

But get a good charger such as one of the Maha/Powerex models.

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

AnAppleSnail said:

Use the NiMH. Here are some useful details:

1. All batteries suffer some voltage drop when you draw current from them. Alkaline AAs suffer TERRIBLY when you try to get more than about half an amp out of them, and drop below 1.0v per cell at high drain.

2. NiMHs of decent quality ($20 for eneloops) will last you about 1000+ charge cycles, compared to $20 of alkalines.

3. Most AA-powered lights are brighter with longer runtimes on the bright modes than on alkalines.

4. Many lights are regulated so that there is little difference in brightness within the range of the driving electronics. This is especially the case for lights with more than 3v of batteries.

Click to expand...

Thanks! Hot Brass

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

Yamabushi said:

+1 on the NiMH

Another good reason : alkalines can leak and damage your flashlight; I've never had a NiMH leak.

But get a good charger such as one of the Maha/Powerex models.

Click to expand...

Yeah,That's the charger brand I am looking at! Thanks,Hot Brass

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

+2 on NiMH

To expand on what the others have said, The TK41 IS a digitally regulated light. This means that the light output doesn't change as long as the batteries have the power to supply. Turbo, for instance, is 800 lumens. The light will continue to produce 800 lumens regardless of what type of batteries are in there until the batteries don't have enough power to run 800 lumens anymore. Once the batteries aren't powerful enough for turbo mode (800 lumens), the light will automatically step down to the next mode (high, 335 lumens). If you were to use alkalines, not only would your output be the same, but you'd be throwing away cells that weren't completely dead because they will no longer have the power for your higher modes. NiMH can just be recharged or topped off and be good to go another round.

I'm not sure where you purchased your TK41, mine did not come with Eneloops. That's a pretty sweet deal. I use Eneloops on my TK41. I started out using alkalines, but I use this light nightly and my battery costs were out of control. I use it on Turbo mode 90% of the time and I don't specifically remember noticing any difference in runtime between Eneloops and alkalines on Turbo, but for some reason I feel like Turbo actually lasts a lot longer on Eneloops :thinking:. The general consensus on CPF is that Eneloops are the best purchase for most AA rechargeable applications. This is explained in great detail here on this forum and is answered many times, in much greater detail than I can possibly explain. If you search eneloop (test, review, etc) you will be overwhelmed with info. My suggestion is a total of 16 Eneloops. While you use one set you can charge one set. This means you can almost run the light continuously on Turbo mode forever depending on your charger set up.

As Yamabishi mentions, you'll need a charger. Maha/Powerex are also highly regarded on the forum. The Maha Powerex MH-C9000 is often considered the best charger for AA NiMH. It has features that you won't find on other chargers. While you probably won't use those features the day you get it, you will want to as time goes on. For now, you could plug the charger in, stick the Eneloops in there, and they'll automatically start charging for you. Once it says "done" you're good to go. Later you can read up and learn all the awesome features of this charger and really optimize and understand your batteries. I started with other chargers, then within a month they were sold and I had the C9000.

I hope this helps. Do some research here on CPF. The amount of information available is absolutely insane. Enjoy!

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

Thanks! Maybe I mis-spoke about the Fenix coming with Eneloops....I probably read that wrong or got confused,so I will see for sure when it arrives! Thanks,Hot Brass

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

The TK41 runs great on alkies but you gotta toss $4.00 worth of batteries after just 1.5 hours on high power every time you do it. I think that AA lithium cells are the best bug out bag cells but definitely nimh for regular use.

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

^Yep. Buy Eneloops, or if you want to save a little money, then try the Tenergy Centura NiMh AA's for about 1/2 the price of Eneloops. I used Eneloop XX's in my TK-41, til I returned it because of a bad switch, But I use Tenergy Centura AAA's in my AAA lights. I currently have alkalines in my other 6-AA light, because I had bought like 48 of them for $14, but once those 6 alkalines go dead, I'll switch to the Eneloop XX batteries I had in my TK41 previously.

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

Run both a TK40 and PA40 on eneloops love them. If the weather out is really cold and the lights are kept in a vehicle I will go with Energizer lithium.

Re: Which batteries for my new Fenix TK-41....1.5 volt Alkaline or 1.2 volt NiMH?

Interesting, this is the same Q&A from back in the day on the TK40 and later the 45, is it not?

'The Rig' almost everyone seemed to agree on is the light, a Maha & 16 Eneloops. Hint, it's a 200 rig.
If you already own a charger and the Eneloops, you're set with only the light expense ahead of you (a much easier 112 or so)

Either way, not much has changed has it