Best rechargeable "D" cell

[mccririck]

Thought I'd let people in the UK know that from Thursday Lidl will be selling rechargeable D cells, they are LSD I think, capacity is 4500mAh, the AA are 2100mAh and the C are 4000mAh, they are also doing AAA (850mAh) and 9V (200mAh)

 

[coachtjm]

Looking at a similar light to tk70, that requires D cell batteries...can you use the eneloops with the adapters or is this unsafe? not recommended? etc? new to this also...

 

[mccririck]

Looking at a similar light to tk70, that requires D cell batteries...can you use the eneloops with the adapters or is this unsafe? not recommended? etc? new to this also...

You can use Eneloops with adaptors but their capacity is only 2000mAh which defeats the point of a D cell light.

 

[StorminMatt]

You can use Eneloops with adaptors but their capacity is only 2000mAh which defeats the point of a D cell light.

A point well taken. One HUGE advantage of D batteries vs smaller batteries (like AA batteries) is runtime. With Eneloops in adaptors, you will get only a quarter to a fifth of the runtime of a true size D NiMH. This isn't going to be very long with a TK70 on Turbo.

Speaking of a TK70 on turbo, another issue with Eneloops is going to be internal resistance. Although even a NiMH AA battery is going to have a low internal resistance, the internal resistance of an Eneloop is going to be several times higher than, say, a Tenergy Centura D battery. Given that a TK70 on Turbo is going to be drawing some MAJOR amps, true D batteries are going to be able to hold their voltage better than AA batteries.

 

[mccririck]

Are Tenergy Centura D the best value?

 

[StorminMatt]

Are Tenergy Centura D the best value?

All of the Tenergy D cells seem to go for around $16 a pair. So whether the Premiums or the Centuras are a better value depends on your use of the batteries. The Centuras are LSD batteries. And, accordingly, they are lower in capacity than the Premiums (8000mAH vs 10000mAH). It all comes down to whether you need a battery that is going to give you maximum capacity to all be used in pretty much one shot right after charging vs something that will be able to hold its charge for intermittent use over a period of months.

 

[Verminator]

357mag1 Thank you for all your great testing info on D cells. I'm sold on the Tenergy Premiums based on your reviews already! A question I have though is, in your opinon, are these batteries also suitable for childrens toys that take D cells? I know this forum is primarily for "flashlight users" but about the only other thing that takes D cells are toys and that is my interest. Assuming they are, what is the best charger for D cells? I have a MH-C9000 my my AA and AAA cells and find it excellent. I'm really happy with that charger and I see Powerex does have D charger. What is your opinion of that?

Finally, have you done any testing on 9V batteries? If so, I see there is also a Tenergy Premium version of them, however I have no idea they only held 2500 mAh on average! For some reason I expected a 9V would have a much larger capacity...but I guess not??

 

[K9Patrol]

Just for the record I have lots of Tenergy Centura cells (16 D, prob. about 60 AA, about the same AAA, 4 9 volts). I've had absolutely zero problems with them and they work great. Haven't seen any bad reviews of them either.

One thing about using multiple cells in a device is that you dont want to ever let them drain until their completely dead - Chances are one of the cells will be weaker than the rest and will get reverse charged. I see this every time I run down alkalines, and have ruined some older Energizer NiMH cells that way (the weak one which got reversed charged read 0.000 volts when I took it off the charger because it defected on it)

I left it on the shelf and eventually it recovered enough to put it on the charger, though running it through a test cycle showed that it only held 1600ma after that, and it was a 2100ma battery..

Not scientific, just observation.

 

[ArcticHighlander]

In my experience all rechargeable nimhs settle out to around 1.3v after they have been off the charger for a certain amount of time. The time varies with each battery type and manufacturer lot.

I have some Eneloops (best nimh LSD) that were charged two days ago and they are still around 1.4v and may take a month to drop down to 1.3v but they will. The Blue Tenergy D cells aren't true 10,000mah cells or at least none of the ones I've tested have reached much over 8000mah. Tenergy Premium (white cells) are true 10,000mah cells so the internal chemistry is slightly different and they will measure different than the Blue cells.

I have run discharge test on both cells and the Tenergy Premium will have more capacity left after 6 months setting unused off the charger than the blue cells do fresh. I've verified this several times with several different batches of cells.

Keep in mind even with just a 2 or 3 amp load both cells will drop to 1.2v under that load so the static voltage doesn't tell you a whole lot about the cell.

In my testing the Tenergy Premium D cell is better than any other D cell on the market.

Hope that helps.

Thanks, 357mag1. I read threw this entire thread and your information has been invaluable. I just ordered a TK70 and a set of 8 Tenergy Premiums for $50 to go with it. Along with the Maha 808m charger. I'd also like to get a TK35 and saw somewhere in this thread that you had a good source at a good price located in the US for Fenix. Could you PM me with the info? I don't have enough posts yet to contact you directly.