Those reports are from over a year ago. Chances are maha has made some changes since then.
JD
Best rechargeable "D" cell
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Those reports are from over a year ago. Chances are maha has made some changes since then.
JD
hank
Flashlight Enthusiast
> Maha MH-C808M
I don't find mention of changes at Maha; I've emailed to ask. It's a switched-mode power supply built in the case, not a wall wart, so overheating could be typical failure -- Wikipedia says what I've read elsewhere, that "switching adapters are more likely to fail than the older type" and mentions a variety of ways it happens.
So it goes; rare anyhow. If I hear anything from Maha I'll mention it, but I'll put it in a charger topic so not to get further off track here.
Meanwhile, on topic -- I just got my eight Tenergy 10,000A D cells (blue with the big lower case "e").
Checked the first four as they came out of the shrinkwrap,
about 0.2, 0.2, 0.4, and 1.0v showing. I've got a CCrane charger that handles D size, I'm using it on the first four. Will follow up.
I don't find mention of changes at Maha; I've emailed to ask. It's a switched-mode power supply built in the case, not a wall wart, so overheating could be typical failure -- Wikipedia says what I've read elsewhere, that "switching adapters are more likely to fail than the older type" and mentions a variety of ways it happens.
So it goes; rare anyhow. If I hear anything from Maha I'll mention it, but I'll put it in a charger topic so not to get further off track here.
Meanwhile, on topic -- I just got my eight Tenergy 10,000A D cells (blue with the big lower case "e").
Checked the first four as they came out of the shrinkwrap,
about 0.2, 0.2, 0.4, and 1.0v showing. I've got a CCrane charger that handles D size, I'm using it on the first four. Will follow up.
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Just got my 16 in the mail today. They are the same blue 10,000 mah with the lowecase "e" as you hank. With my voltmeter the lowest was 0.92 and the highest was 1.08. I also got my Maha MH-C808M in the mail today 
so I have 8 charging in "soft mode" which is 1 amp rate, which Tenergy recommends.
Are you sure they read that low? I didn't think alkalines could output that low of a voltage. What I found interesting is that there was no batch that was really different that the other. Of the 4 x 4 packaged cells, each pack had 1 or 2 over a volt and 2 or 3 that were under. I was expecting to see one package have all over 1 volt and another package to have all under a volt.
so I have 8 charging in "soft mode" which is 1 amp rate, which Tenergy recommends.Are you sure they read that low? I didn't think alkalines could output that low of a voltage. What I found interesting is that there was no batch that was really different that the other. Of the 4 x 4 packaged cells, each pack had 1 or 2 over a volt and 2 or 3 that were under. I was expecting to see one package have all over 1 volt and another package to have all under a volt.
I just checked the charging and both batteries and charger are cold to the touch (my basement is probably 65ish degrees year round). All batteries right now have 2 of the 3 bars visible and flashing. When I inserted all the batteries at first, only 1 of the 8 had 0 of 3 bars visible. The other 6 had 1 bar and 1 even started charging with 2 bars.
hank
Flashlight Enthusiast
Those first numbers came from the CCrane's battery analyzer mode.
On the other hand, it's already telling me it's up to trickle charge mode
-- way less time than I'd expect if the cells were that low. So, maybe that analyzer voltage was low.
I don't see how I could've messed up measuring it, it's just put in one cell and push the button.
But I've screwed up simpler tasks on occasion.
While that's charging those four, I've now checked the second four right out of the shrinkwrap with one cheap multimeter -- three at about 0.9 and one at 0.7, plus or minus a hundredth.
So that's better. I've double checked with my other cheap multimeter and got consistent numbers; it runs about 0.1 lower but that was consistent across all four.
Once the CCrane is finished with the first four, I'll see what how it reads the second four.
Could well be that measure is running low, I don't think I ever checked its accuracy on that mode.
---- EDIT -- ok, the CCrane showed it finished charging (it has one indicator for all four, and to be fair does say it's best if all the cells are at about the same starting level).
Using the CCrane's Analyze function then, the three cells that had started at 0.2-0.4v originally show as 1.35 or 1.37v, all five bars.
And a cheap multimeter shows them as 1.36, 1.36, 1.35v.
The one cell that had been 1.0 originally now shows as 3 of 5 bars and about 1.2v. So I'm putting it back on charge and will see if it comes up.
On the other hand, it's already telling me it's up to trickle charge mode
-- way less time than I'd expect if the cells were that low. So, maybe that analyzer voltage was low.
I don't see how I could've messed up measuring it, it's just put in one cell and push the button.
But I've screwed up simpler tasks on occasion.
While that's charging those four, I've now checked the second four right out of the shrinkwrap with one cheap multimeter -- three at about 0.9 and one at 0.7, plus or minus a hundredth.
So that's better. I've double checked with my other cheap multimeter and got consistent numbers; it runs about 0.1 lower but that was consistent across all four.
Once the CCrane is finished with the first four, I'll see what how it reads the second four.
Could well be that measure is running low, I don't think I ever checked its accuracy on that mode.
---- EDIT -- ok, the CCrane showed it finished charging (it has one indicator for all four, and to be fair does say it's best if all the cells are at about the same starting level).
Using the CCrane's Analyze function then, the three cells that had started at 0.2-0.4v originally show as 1.35 or 1.37v, all five bars.
And a cheap multimeter shows them as 1.36, 1.36, 1.35v.
The one cell that had been 1.0 originally now shows as 3 of 5 bars and about 1.2v. So I'm putting it back on charge and will see if it comes up.
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hank
Flashlight Enthusiast
Second shrinkwrapped batch of four Ds -- which showed three at about 0.9 and one at about 0.7 on the multimeter -- tested on the CCrane 'Analyze' function at much less, 0.14, 0.17, 0.17, and 0.34. So something's odd there. This time I'll try charging just two at a time on the CCrane, having belatedly found the note at their website saying the charger (500ma 12v power supply) may not handle four at a time for high rated large cells.
Oddity -- holding these D cells with the multimeter probes, the voltage shown slowly and steadily increases over time. Do the batteries "wake up" when first tested?
Oddity -- holding these D cells with the multimeter probes, the voltage shown slowly and steadily increases over time. Do the batteries "wake up" when first tested?
357mag1
Enlightened
My 16 cells all showed between just below .8v to just over 1v right out of the shrink wrap.
hank
Flashlight Enthusiast
Charging just two in the CCrane took a couple of hours -- up to 1.37 and 1.38v. So I suspect it terminated early when I was trying four at a time. I'll check them again tomorrow.
Good enough to convince me to buy more of these cells while they're available.
Then I'll want a better charger ....
Good enough to convince me to buy more of these cells while they're available.
Then I'll want a better charger ....
357mag1
Enlightened
Soft charge mode is 1amp per hour so you are looking at around 8 hours.
Yes, that's what I figured. I went to bed and the charging was 5.5 hours in. They were all charged when I woke up this morning. I put the second set of 8 on the charger. Hopefully they should be charged when I come home and my TK70 will be at the doorstep! I'll have to rig up my D cell to AA cell setup to use the C9000 to do a "discharge" test of each battery and start getting their mah numbers so I can match my D cells like I have with my AAAs and AAs.
jayflash
Flashlight Enthusiast
Hank, if your CCrane is like mine, it share total charging current between all bays. One cell should charge at about 1.5 amps and each additional cell will evenly divide that -- unless our chargers operate differently. The same is true for the discharge or analyze function. To obtain the slowest discharge rate, put in four cells. To get the highest charge rate, do the opposite and install only one cell.
It seems that your cells need several charge/slow discharge cycles, because your charge time is way too fast.
hank
Flashlight Enthusiast
Thanks Jayflash -- I've got a quite old CCrane (repaired the springs after they failed a while back); not sure if the newer ones are any different about charging.
The manual for it does mention needing several cycles. I'm on my first cycle for these batteries, so expect them to shape up after a few cycles.
The manual for it does mention needing several cycles. I'm on my first cycle for these batteries, so expect them to shape up after a few cycles.
357mag1
Enlightened
After doing all of my discharge tests multiple times to make sure my broken MD-3000 wasn't causing any erroneous readings I have four of the Tenergy Blue batteries staying just below 7000mah and one more hovering around 6000mah. These are all in the Maha 808 going through a conditioning cycle to see if they will come up any. All of them have been through at least 4 or 5 charge/discharge cycles so I don't expect to see much if any improvement.
These batteries would be fairly rated at around 7500mah as that seems to be about the median for 16 of them. Guess that is why they came out with the Premium replacement. The good news is they seem to hold their voltage just as well as the Premiums under load. I would take these over the garbage AccuEvolution cells any day.
Just to keep in in perspective the Tenergy Premium batteries I own vary in capacity readings from around 9000mah to about 10,400mah. Chinese batteries always seem to have a larger variance. If we could get a Japanese company or "Quality" American company to develope some D Nimh cells we would have some killer Deeees!!!
Man, that is disappointing! At first I was expecting 10,000 mah as advertised. Then read on here that realistically they are more like 8,000 which is not toooo bad. But anything below that, well now that's crap. My modded Rayovac lanterns take D cells but I have been using the AA to D cell adapters. At 1.4a on the highest mode for an XML, the higher capacity cells would clearly win here, which is what I initially wanted - runtime.
I bought some stuff to make adapters for my D cells to fit into my Maha MHC9000. SO hopefully I'll have it rigged up tonight. What should I do to test the mah values of mine? Just stick them in and discharge at 1 amp for each cell? it would take about 8 hours I presume.
357mag1
Enlightened
I would say you are looking at approximately 8 hours to discharge a cell.
Remember my tests are at 3 and 5amps to more closely simulate how I use these batteries.
At about $3.13 a cell shipped to our door I'm still pretty happy. You have to figure at that price they must have been old stock that had sat around for quite some time.
I paid a whole lot more for my AccuEvolution cells and they made my incadescent light (ROP HI) look sick. The cells were not even usable for the application. These Tenergy Blue cells run it as bright as any cell I've used and do it for over 1hr 35mins.
These Blue cells will run my newer TK70 on Turbo using 3 cells the AccuEvolutions sag so bad it drops to high in about 23 seconds.
Remember my tests are at 3 and 5amps to more closely simulate how I use these batteries.
At about $3.13 a cell shipped to our door I'm still pretty happy. You have to figure at that price they must have been old stock that had sat around for quite some time.
I paid a whole lot more for my AccuEvolution cells and they made my incadescent light (ROP HI) look sick. The cells were not even usable for the application. These Tenergy Blue cells run it as bright as any cell I've used and do it for over 1hr 35mins.
These Blue cells will run my newer TK70 on Turbo using 3 cells the AccuEvolutions sag so bad it drops to high in about 23 seconds.
Two of the cells are still "soft" charging on my Maha. They have been charging for 13 hours now. I went to home depot and bought a wooden dowel that was the closest size to an aa battery to make an adapter for my C9000. THe dowell was a little too thick and I finally got irritated after my 3rd try to make it fit in there with my copper wires that I gave up. I'll have to figure out another way to get an adapter to work so I can start doing battery matching with the Tenergys.
EDIT: The last two cells took about 13.5 hours to charge. I took them off the charger. With my volt meter I quickly checked these 8 that just came off the Maha, and the 8 that came off yesterday. The range of the 8 charged today was 1.39 to 1.42. Yesterdays was 1.35 to 1.4.
Amazon has multiple reviews of these batteries, and I forget where the link is but these were tested with other D batteries and the capactiy came up as a smuge under 8,000 mah. The Amazon reviews seem to be both good and bad, with the worse reviews being most recent. No doubt QA/QC has sunk, but there seem to be good and bad batches of these batteries.
http://www.rechargeable-battery-rev...battery-tests/d-nimh-battery-performance.html
I ended up buying a pack of those AAA to AA adapters so I will simply wire them up as a dummy cell to my D cell holders that I will have to modify (from series to individual) from Radioshack so I can do discharge tests. I have a feeling that cell matching with these batteries is an absolute must.
I'm not sure the maximum discharge capability of the C9000 but I'll have to check. I could do multiple tests per battery 1 amp, then 2 amp, then 3 amp if it's available. This would probably take a while to do but meh. I bought the TK70 for snorkeling in the late spring so I won't really be using the TK70 much beforehand.
EDIT: The last two cells took about 13.5 hours to charge. I took them off the charger. With my volt meter I quickly checked these 8 that just came off the Maha, and the 8 that came off yesterday. The range of the 8 charged today was 1.39 to 1.42. Yesterdays was 1.35 to 1.4.
Amazon has multiple reviews of these batteries, and I forget where the link is but these were tested with other D batteries and the capactiy came up as a smuge under 8,000 mah. The Amazon reviews seem to be both good and bad, with the worse reviews being most recent. No doubt QA/QC has sunk, but there seem to be good and bad batches of these batteries.
http://www.rechargeable-battery-rev...battery-tests/d-nimh-battery-performance.html
I ended up buying a pack of those AAA to AA adapters so I will simply wire them up as a dummy cell to my D cell holders that I will have to modify (from series to individual) from Radioshack so I can do discharge tests. I have a feeling that cell matching with these batteries is an absolute must.
I'm not sure the maximum discharge capability of the C9000 but I'll have to check. I could do multiple tests per battery 1 amp, then 2 amp, then 3 amp if it's available. This would probably take a while to do but meh. I bought the TK70 for snorkeling in the late spring so I won't really be using the TK70 much beforehand.
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I have purchased 36 of the batteries from ebay, all of them came out of the shrink wrap between .899 - 1.08v... I started them all of with a charge cycle to wake em up, then cycled them through a 3a discharge and, some at 5a charge, and some at 2a charge.. I have found they all have over 8000mah.. My triton2 charger has actually "mah'ed" out at 9900mah on a couple of charge cycles (most of these were with 8 cells or more in the charge loop) but with 4 cells discharging/ charging at one time I find that 8500-9500mah is the norm with most of them being over 9000mah...
and its already been said once, at just over 3.00 dollars a cell shipped, you really can not complain even a little bit if they are less than 10,000mah... lol
and its already been said once, at just over 3.00 dollars a cell shipped, you really can not complain even a little bit if they are less than 10,000mah... lol
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