I really need some new Nimh D cells for a new build, but after some brief googling, I can’t seem to find any. Only D shells for a single AA. I know there are D eneloops, made with three AA cells spot welded together, but i can’t find those either.Those eneloop ‘D’ cells were only like 6000 mAh if I remember correctly anyway. Something with some solid capacity would be ideal.
Tenergy are hit or miss as far as am concerned. You can buy 4 cells and all four will be good and then you can buy 4 and 2 will be good and 2 will not hold a charge for long, or won't charge all the way up. I have never really cared for them. Sometimes they are all you can afford, but they usually do not meet the claimed output. Ten amp NiMH D cells usually ran about 4-5 amps max, on the ones I got.
Others may have great success with them, but I never had real good luck with them.
There are still a lot of the old discontinued Tenergy “light blue with a lower case ‘e’” NiMH cells for sale.
There must have been a bad batch or a lot of heat damaged cells — their website no longer offers the ones with that color wrapping.
They were inconsistent — some good, some poor, and quite cheap from time to time.
I think the reason the D NiMH’s are crap is because the manufacturers know what Old-lumens said. D cells don’t sell to well, so it doesn’t make much sense to put more R&D into it to allow for more current capacity. The same philosophy would explain why tesla chose 18650 because it was already the pseudo-standard of the lithium-ion cell industry.
Aside from that, I agree 4 AAs may be a better choice. Better quality control to say the least.
@Sharpie - Tesla uses 18650’s (assuming the question wasn’t rhetorical). Lipos are flat because they are more ‘fun’ that way. Four AA’s taped together are NOT the same diameter as a D cell. Try and shove them into the tube of a brand new Maglite. Won’t work, but a D cell will. Some quick circle packing ratios will show you that it’s not the same thing.
@Lightgecko - there are a variety of 3xAA to 1xD adapters (carriers). Here is one inexpensive example. Those may serve your needs at a better price-point than actual D cells (since as OL said - quality AA cells are in better supply). From reading the OP, you sound dissatisfied with even 6000mAh NiMH cells - what application has you interested in such high capacity?
@Sharpie: I hope you like surprises! Nearly all older members here and moreso at CPF can tell you that Maglite reduced the inner diameter of D cell flashlights when the serial numbers changed. This applies to both incan (first) and LED (when introduced). They also reduced the OD by a lot. It’s to the point where I can pickup one of each and butt them up against each other and instantly see the difference - it’s that much! Anything without a “D” in the serial number is huge compared to the new stuff (which will feature a D or a DL). I’ve personally done some work on carriers (a / b) for putting AA’s in Mag D’s, so I’m very familiar with the fitment. The diameter of a D cell and ~2.4x the diameter of a AA are definitely not the same number.
From what I’ve read on the internet over the years I’m inclined to agree with you about 3xAA NiMH beating 1xD NiMH. The exception might be those Powerex cells, at least in a medium to low drain application. Looks like they might edge out 3x Eneloop X AA cells.
Alkaline beat everything but “Lithium Primary” cells at the capacity game. Many other characteristics are very poor. Temperature related stuff, high-drain stuff, leakage, etc.
I guess I’m just lucky. I have about 20 of the blue Tenergy cells, purchased over the course of a couple of years and I’ve had no problem with them. I doubt they are 10,000 mAh, more like 8,000 but that’s just a guess. They will run a long time in my converted Mags (up to 6.0A on one) and I’ve had them for a few years with no noticeable change in output.
I also have about 50 of the Tenergy Centura AA and AAA cells and see no real world difference between them and my Eneloops.
The blue label cells are no doubt a lower quality cell than the Centura or Premium Tenergys.
Thanks Wight. I appreciate the links. Massive respect for you and Old-Lumens for your respective niches.
As for why I want more capacity, if I’m carrying around large D cell size light, I want to take advantage of that form factor as best as I can. Now I understand that we run into a similar problem as Chinese lumens in really cheap ebay advertising. The ‘rated’ capacity is nothing like reality, so 6000 actual mAh is much better than 10,000 ‘advertised’ mAh.