Are you sure that your batteries weren't bad? I've actually heard others say that the Premiums and Centuras both give them about the same amount of runtime on Turbo in a TK70 (about 1:15). By the way, I have noticed that Tenergy rates the Premiums as being able to deliver a maximum current of 47.5A vs only 7.8A for the Centuras. I actually spoke to one of the engineers at Tenergy about this, as I didn't want to buy Centuras if they're even wimpier than your typical Eneloop (which can do 10A). They assured me that the Centuras could do a 5C discharge (~40A) just like the Premiums, and weren't sure why the Centuras were rated so low. But to this day, those numbers are still on the website. I should also note that measurements of internal resistance show that the Centuras actually have a slight edge compared to the Premiums.
All right, you had me unpack a box (just freshly moved) to double-check if my memory is still there... I did make a slight mistake. I currently use the Tenergy Premium (non-LSD) in my TK70, which work just fine. The batteries that did not work up to spec are Accuevolution (Accupower) 10 000 mAh LSD's (not Tenergy LSD... oops... I did want to buy Tenergy LSD's at the time, though). The accupower gave me the 1:15 runtime for a few cycles and then the runtime on turbo went down to 15 minutes and then around 15 seconds only a small number of cycles afterwards. I was told by guys who really know their stuff (local battery warehouse) that the Accupower are pretty much as good, if not the same, as the Tenergy as they are most likely made in the same facility. Those guys do know their stuff and I did double-checked a lot of their sayings and it turns out they seem to be 100% on track.
Is it possible the claims about the Centuras running fine were only a first impression, same as I got with my accupower LDS's? If you had asked me in the first week I got my TK70, I would have said buy the Accuevolution and nothing else, yet now I say don't use those in a TK70 ever (non-LSD is quite possibly fine, though).
The specs I just found rate the Tenergy Centura at 0.5C, not 5C, consistent with my personal experience and advice from the guys at the warehouse I bought all my high capacity D cells at:
- Industrial high capacity rating for long lasting performance.
- Advanced low self-discharge NiMH technology to maintain charge during inactivity.
- No memory effect.
- Replacement for Alkaline D size.
- Can be charged up to 1000 times.*
- Maximum Discharge Current: 1C
- Charge Current:
- Standard: 780mA x 16 Hours
- Rapid: 1560mA x 7 Hours
- Maximum Discharge: 7.8A (exact same as the accuevolution 10 000mAh LSD; too low for the TK70 @ 10-11 amps)
- Standard Discharge: 0.2C - 0.5C
- Weight: 145g
- Operating Temperature: -10°C - 50°C
- Operating Humidity: 45% - 85%
- Storage Temperature: -20°C - 30°C
- Dimensions: 61.5mm x 33mm (H x D)
I'm wondering where that 5C discharge rate spec came from as I just
Is it possible the Centura have an exceptionally high discharge rate for LSD's?
My actual research was limited to the guys at a specialized battery distributor and a quick check on the internet, but in all the conversations I had with them, they do seems to know their stuff. One major possible difference between you data an mine is that I use 10 000 mAh batteries
I do suspect, however, that their stocks could be a little old and the batteries might have been sitting on the shelves for well over a year