Fenix tk70 on duracell 3000mah cells

Hi all. I know this has been asked a few times regarding using alkaline d cells. But I couldn't find any conclusive info on using low capacity nimh cells. Due to budget constraints I can only afford duracell 3000 mah cells at the moment. Are they safe to use or am I going to damage something?
Thanks

Assuming you'll put these batteries in your Fenix TK70, you can use them in that light. But, since the TK70 asks a lot of those batteries in the highest mode, it's possible the runtime will be very short or that it won't even work. Alkalines can be uses, but should be removed when the light won't be used for a couple of days. Also check regularly, to see if they're still ok.

Thanks. Ive fully charged the cells and it does hit turbo but drops to high after 10 seconds. It has a audible rasping sound coming from the light on turbo... What is that?

Oh never mind I've discovered it's induction whine and harmless should have searched first.:shakehead

Thanks again

torchsarecool said:

Thanks. Ive fully charged the cells and it does hit turbo but drops to high after 10 seconds. It has a audible rasping sound coming from the light on turbo... What is that?

Oh never mind I've discovered it's induction whine and harmless should have searched first.:shakehead

Thanks again

Click to expand...

The TK70 draws around 10 amps at full output - that's about a 15 minute discharge rate for a 3000 mah cell. Because of all that chemistry inside, batteries perform better when slowly discharged, over a couple of hours. Your TK70 won't really be happy until you can get some good 10,000 mAh full-size D cells for it. Even then, that's a 1 hour discharge rate and only good quality cells will perform well.

I've never been able to get my TK70 to full output on alkaline primaries, even buying fresh national-brand cells. Looking at the Energize technical information on their web site, it's not surprising when you realize even a good alkaline D cell has a considerable internal resistance that's not really compatible with delivering 10+ amps.

My least favorite feature of the TK70 is that on low or under-capacity batteries, it will get hung up in one mode and stay there. It'd be nice to toggle between 20 lumens and 300 when running on alkalines, but going round the circle will eventually get you stuck in the highest mode the current load of batteries can support....and there you stay.

Love that light, it's an insane amount of light for something you can carry around with you - literally as much light as a car headlamp.

Bill

Thanks bill that information has been very helpful.

I will save up for some better cells. Will have to make do with the odd short blast for now. Need to be a flipping millionaire to keep up with this hobby

The TK70 was my first serious LED light and I still use it almost daily but power it with two big lion cells that fit in the 3 D cell handle

The TK70 has very demanding battery requirements. I used Maha Imedion 9500's which were able to maintain turbo for the full battery life. Although, if they haven't been used for a few months, I had to do a discharge-charge cycle on my Maha c808m charger.

You can use lower quality cells or alkalines, but these are only good for the lower output modes.

Thanks for the recommendation I will make the maha cells the goal I think.
Although they may get put on hold longer as somebody is tempting more money out of me with some mags!

I am planning to buy imedion 9500, for my tk70.I choose them over tenergy (centura/premium),or powerex(1100) due to its LSD features.It sure is expensive than tenergy ,but since I have the maha charger ,I think it will be good if we buy same brand cells .(correct me if Iam wrong)
Anybody used imedion 9500 in tk70 for a long time ,how is the performance compared to others.

Fenix specs for the TK70 were attained using 9000mah D NiMH's. BatteryJunction.com has 10000mah Tenergy's for $7.29 per cell and 10000mah Tenergy Premium's D NimH's for just 30 cents more at $7.59 per cell. Do not know the different between the two but have a few lights with the Premium's they work very well. The Imedions should work as well..