Best rechargeable "D" cell

[Sagebrush]

I use a 4 d fan from academy. I thinks its a timber creek . It will go two nights . Its the yellow and black one with the led lights.

My blue tenergies shut off at 1.40 using the tenergy charger. Same with the premium ones . Its probably the 7.5 hour timer.

Sent from my GT-S5690L using Tapatalk

 

[CyberCT]

I am having a bit of an issue with the Tenergy Blue D Cells from that ebay seller. My cells also arrived with a very low voltage. all were in the .9 range. When i charge them via the Maha 9000 the cells will never get to 1.47 volts for them to terminate. The voltage just stays at 1.41 and never goes up. I put 12,000mAh into them and it never went past 1.41 volts. They also never got hot.
After the Maha, i i put the cells on my hobby charger and they terminate right away when the peak delta is set to 5mV. They only discharge to about 7,000mAh. I'll try to exercise them and see if they open up. Anyone else seen this?

Thanks,
JD

How did you charge them on the Maha C9000? My initial plan was just a discharge per cell at 1 amp on the C9000 to get the capacity per cell. Charging them is done on my Maha 808D. Also, I used a volt meter for each cell off my 808D and none of them were 1.5v. They were in the 1.4v range. But that's normal, my eneloops come off in the 1.4v range too.

 

[Sagebrush]

How did you charge them on the Maha C9000? My initial plan was just a discharge per cell at 1 amp on the C9000 to get the capacity per cell. Charging them is done on my Maha 808D. Also, I used a volt meter for each cell off my 808D and none of them were 1.5v. They were in the 1.4v range. But that's normal, my eneloops come off in the 1.4v range too.

I don't have any fancy chargers and my D cells just came off the V-9688 at 1.42 to 1.40. After three hours they are reading 1.35. Thats the first charge on new blue D cells. This batch of 4 were all .88 out of the box.

I didn't know that they could reach 1.5? My Premiums stay 1.35 to 1.38 after sitting a day or so. Is that right?

 

[JudasD]

How did you charge them on the Maha C9000? My initial plan was just a discharge per cell at 1 amp on the C9000 to get the capacity per cell. Charging them is done on my Maha 808D. Also, I used a volt meter for each cell off my 808D and none of them were 1.5v. They were in the 1.4v range. But that's normal, my eneloops come off in the 1.4v range too.

I just have dummy cells that have wire outputs that then go from the maha 900 to a cradle for my cells. I charged them at 2A. The maha 9000 terminates at 1.47v. This is the voltage that is read DURING charge. I have Tenergy Premium and Centura D that will both terminate at 1.47 on the maha. Right after charge they will read high 1.3x or low 1.4x. These blue Tenergy will just sit at 1.41 and keep taking charge current. they never got hotter and the volts never go any higher. They must have a very high internal resistance. Maybe from sitting on the shelf for a very long time in a discharged state?

JD

 

[Russel]

I just have dummy cells that have wire outputs that then go from the maha 900 to a cradle for my cells. I charged them at 2A. The maha 9000 terminates at 1.47v. [...]

Remember that unless you have one of the older MH-C9000 chargers, there is a limit of about 4500mAh (if I remember the number correctly) in every [edit] Charge [end edit] mode except break-in. Break-in mode has a limit of 20000mAh, if I remember correctly. Of course, you can always run a second charge cycle to completely charge 5000mAh to 10000mAh D cells.

 

[JudasD]

Remember that unless you have one of the older MH-C9000 chargers, there is a limit of about 4500mAh (if I remember the number correctly) in every mode except break-in. Break-in mode has a limit of 20000mAh, if I remember correctly. Of course, you can always run a second charge cycle to completely charge 5000mAh to 10000mAh D cells.

Yes, i have one of the newer ones. I have to run multiple charge cycles back-to-back. So far i have run 3 cycles and it will never terminate and just stays at 1.41 volts. On my Tenergy D Premiums, which are also 10,000mAh, the charger usually terminates in the middle-ish of the 3rd cycle when it hits 1.47 volts.

JD

 

[CyberCT]

Remember that unless you have one of the older MH-C9000 chargers, there is a limit of about 4500mAh (if I remember the number correctly) in every mode except break-in. Break-in mode has a limit of 20000mAh, if I remember correctly. Of course, you can always run a second charge cycle to completely charge 5000mAh to 10000mAh D cells.

Wait, so the C9000 will not discharge my blue Tenergy D cells completely, if I do a discahrge mode? My initial intention was to do a discharge at 1 amp for all my Tenergys and see their capacity. I don't want to run 2 discharge mode cycles.

 

[JudasD]

Wait, so the C9000 will not discharge my blue Tenergy D cells completely, if I do a discahrge mode? My initial intention was to do a discharge at 1 amp for all my Tenergys and see their capacity. I don't want to run 2 discharge mode cycles.

It will discharge them completely. It is the charge cycle that is limited to 4,000mAh per channel. So you will have to do back-to-back charge cycles until the charger terminates on its own.

JD

 

[sadtimes]

I've done OK with those blue ones from that vendor. Out of the plastic they are really low at .87 to .94, mine have charged up so far. I'm putting them in my lanterns, mag lites and my tent fan. It sure helps the wallet at half the price of my Tenergy Premiums. :thumbsup:

All of mine had similar voltage out the plastic. I charged them, then discharged, then charged again. They all seem fine and perform just fine.

I have several mag lights that I have custom SST-90 builds in and these cells deliver over 10 amps with no trouble...

 

[357mag1]

Wait, so the C9000 will not discharge my blue Tenergy D cells completely, if I do a discahrge mode? My initial intention was to do a discharge at 1 amp for all my Tenergys and see their capacity. I don't want to run 2 discharge mode cycles.

I discharged three of my cells at 1amp to help give you a comparison. Even though there seemed to be no difference doing it at 3amps or 5amps when done at 1amp capacity showed between 600-650ma higher.

My low capacity cell that was averaging right around 5900mah gave 6506mah. By subtracting 600mah you should have a pretty valid idea of capacity per cell at the load your TK70 pulls.

 

[CyberCT]

I discharged three of my cells at 1amp to help give you a comparison. Even though there seemed to be no difference doing it at 3amps or 5amps when done at 1amp capacity showed between 600-650ma higher.

My low capacity cell that was averaging right around 5900mah gave 6506mah. By subtracting 600mah you should have a pretty valid idea of capacity per cell at the load your TK70 pulls.

Thanks for the heads up. I'll keep that in mind when I use my C9000 to do the discharge test for my Tenergys.

 

[CyberCT]

I went downstairs and checked my 808M charger before work. It's been running a "soft" "conditioning" cycle for over 2 days on my second batch of 8 Tenergy blue D cells. I noticed that the "condition" indicator was no longer present on the readout, but "soft" was there. I know both were on the indicator previously. I don't remember what was on the display after the first batch of 8 D cells went through the "soft" "conditioning" mode but is it normal for "condition" disappear from the indicator toward the end of the whole cycle?

 

[Danielight]

Avoid the AccuEvolution D cells at all cost. The old cells were great, the cells they presently sell are the worst D rechargeable cells I have tested and I've tested a bunch.

The Imedion D cells are not much better.

That leaves us with Tenergy cells which are surprisingly good for the price. Check out all-battery.com for the Premium D cells. They are actually better at holding voltage under load than the original AccuEvolution D cells which were awesome cells.

Avoid the Titanium D cells, while I haven't tested the D cells their C cells are the worst I've tested which leads me to believe their D cells would be poor as well.

Hope this helps

Hmmmm ... you mean like the Titanium D12000 rechargeables available thru Battery Junction? I bought several of those thinking I might need them for my big MagLight, but they have been sitting in a charger ... haven't used them yet!

 

[357mag1]

Hmmmm ... you mean like the Titanium D12000 rechargeables available thru Battery Junction? I bought several of those thinking I might need them for my big MagLight, but they have been sitting in a charger ... haven't used them yet!

Yes, if they are anything like the Titanium C cells they won't meet there capacity and sag terribly under load. Not unusable but there are much better choices on the market. Until somebody comes out with something better than the Tenergy Premium D cells they are my choice.

 

[357mag1]

I went downstairs and checked my 808M charger before work. It's been running a "soft" "conditioning" cycle for over 2 days on my second batch of 8 Tenergy blue D cells. I noticed that the "condition" indicator was no longer present on the readout, but "soft" was there. I know both were on the indicator previously. I don't remember what was on the display after the first batch of 8 D cells went through the "soft" "conditioning" mode but is it normal for "condition" disappear from the indicator toward the end of the whole cycle?

I'm pretty sure the word "conditioning" stayed on mine the whole time but can't swear to it. My cells took about three days to complete.

 

[jayflash]

When running lengthy tests, conditioning, and recharging, the chance of very brief power outages, sags, surges or spikes may fool the charger and reset it. I'll have to re-read the owner's manual about the missing "conditioning" indicator, but I remember mine did that at least once.

Now I use a spike protected UPS to supply my chargers and, so far, haven't had previous problems.

 

[CyberCT]

It took 2.5 days to complete the whole cycle. I have a 350watt hour battery that is connected to my charger, and the battery is also connected to the wall outlet. So in a way it acts like a UPS. I ran all my chargers off of it and the first conditioning cycle as well on the 808M.

I checked the owners manual too but in those 2 pages, there's no mention of this issue. I emailed Powererex this morning.

 

[jayflash]

Is that about the size of three "typical" 12v SLA batteries or garden tractor size? That's big enough for any normally short AC outage. May I assume the battery charger and 808 are attached in parallel with the battery? The battery should act as a large capacitor to help limit spikes, but maybe some AC aberration got through.

 

[CyberCT]

Is that about the size of three "typical" 12v SLA batteries or garden tractor size? That's big enough for any normally short AC outage. May I assume the battery charger and 808 are attached in parallel with the battery? The battery should act as a large capacitor to help limit spikes, but maybe some AC aberration got through.

No. My 350w hour battery is acting as the power source. Here is what I have:
http://www.goalzero.com/shop/p/64/Extreme-350-Adventure-Kit/1:3/

The specs of the battery are on the middle of the page. The battery is plugged into the wall outlet at all times while charging my D cells, so the wall outlet keeps supplying power to the battery, acting like a UPS.

 

[Russel]

It took 2.5 days to complete the whole cycle. I have a 350watt hour battery that is connected to my charger, and the battery is also connected to the wall outlet. So in a way it acts like a UPS. I ran all my chargers off of it and the first conditioning cycle as well on the 808M.

I checked the owners manual too but in those 2 pages, there's no mention of this issue. I emailed Powererex this morning.

Are you using an inverter between the battery and the MH-C808M charger?

Oops! You answered my question in your next post...