Resistance values of new Tenergy 10000mAh D-Cells

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Zebretta
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Resistance values of new Tenergy 10000mAh D-Cells

Hi,
I just received 4 Tenergy Blue lable 10,000mAh D cell batteries and tested their resistance values before ever charging or using them.

The values were 80, 92, 89 and 102

Are these acceptable values for these batteries?

What are “optimal” resistance values for these batteries new ?

Thanks

HKJ
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As a internal resistance value in milliohm they are way to high, AAA is better.
The problem is probably not the batteries, but your measure equipment do not measure a correct milliohm value.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Zebretta
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After discharging to .9v and then putting the battery on charge for 16 hours at 1.0amp, the battery never finished the charge and leveled out at 1.43v

Even after 16 hours, it never completed the charging process and would never go above 1.43v

I thought a NiMh should charge to 1.45 or better (even though 1.45 is considered max charge?)

Also, the internal resistance hovers around 50 – 60 Milli-ohms.

I’m beginning to believe I received some batteries that sat on a shelf for a LONG time maybe ?

Should I increase the charging current from 1.0 amps to maybe 2.0 amps or higher ?

btw: I’m charging these on an iMax B6 mini (if that makes any difference)

stephenk
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Zebretta wrote:
After discharging to .9v and then putting the battery on charge for 16 hours at 1.0amp, the battery never finished the charge and leveled out at 1.43v

Even after 16 hours, it never completed the charging process and would never go above 1.43v

I thought a NiMh should charge to 1.45 or better (even though 1.45 is considered max charge?)

Also, the internal resistance hovers around 50 – 60 Milli-ohms.

I’m beginning to believe I received some batteries that sat on a shelf for a LONG time maybe ?

Should I increase the charging current from 1.0 amps to maybe 2.0 amps or higher ?

btw: I’m charging these on an iMax B6 mini (if that makes any difference)

I’ve seen similar charging behaviour on older and well used (non Eneloop) NiMH batteries.
flydiver
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This is an opinion, but based on a lot of reading about RC chargers.
There are “real” IMAX B6 chargers. They are decent. They are the MOST highly copied of this style of RC (hobby) charger. Unfortunately some of the copies just aren’t very good. The area they have the most problems is charging NiMh.
Then along came the ‘mini’. It’s worse. Frankly for NiMh I wouldn’t trust it. I would be skeptical of any output I got out of it.
I’d say you are trying to determine if your batteries are any good when your charger is questionable.
Resistance checking with these chargers is lousy at best. I certainly wouldn’t base critical decisions on that data.

You bought them…..use them. If they work, then you are good. You will find very few people here with much experience with NiMh D-cells and fewer with experience on those particular batteries. I’m one that has used them. Like I told you, they aren’t very good batteries. They aren’t horrible, but for a bit more money you could have gotten something a lot better.

To Air is Human, to Respire….Divine.

Zebretta
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flydiver wrote:
This is an opinion, but based on a lot of reading about RC chargers.
There are “real” IMAX B6 chargers. They are decent. They are the MOST highly copied of this style of RC (hobby) charger. Unfortunately some of the copies just aren’t very good. The area they have the most problems is charging NiMh.
Then along came the ‘mini’. It’s worse. Frankly for NiMh I wouldn’t trust it. I would be skeptical of any output I got out of it.
I’d say you are trying to determine if your batteries are any good when your charger is questionable.
Resistance checking with these chargers is lousy at best. I certainly wouldn’t base critical decisions on that data.

You bought them…..use them. If they work, then you are good. You will find very few people here with much experience with NiMh D-cells and fewer with experience on those particular batteries. I’m one that has used them. Like I told you, they aren’t very good batteries. They aren’t horrible, but for a bit more money you could have gotten something a lot better.

Thanks flydiver.

I understand. Not many here with experience with D cells.
Much of my decision came from candlepower forums where some there have tested many D cells and actually said the Tenergy D cells came out on top in testing…
D cell discussion

I didn’t see anything “a lot better” for “a bit more”. I guess I missed the best bet?
I did see “EBL” rechargable D cells. Are those the ones that are a lot better?
Can you point me in the right direction for a better battery as I may return these. Not sure yet.
Like you say…they aren’t horrible for the money. I paid $27.00 delivered for the 4.

I do actually have 2 new chargers on the way. One is a Turnigy Accucell-6 and the other is a AccuPower IQ338XL so hopefully between all 3 of my chargers I can get a better picture of the state of these batteries.

I understand your comment about the iMax B6. There are indeed a lot of cheap ones.
Just to clarify, I made sure I bought an authentic unit. It was a bit more and came from a highly rated authorized dealer here in the USA and has the authentic hologram on the bottom.

The reason I tend to trust it is because I charge some fairly expensive lipo batteries with it and it has always done good with those.
Granted they are a different chemistry. But with the lipos, I get cell resistance values of 5 – 7milliohms

Anyway,
Thanks again for your reply and I appreciate it.

flydiver
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The [flydiver] in that candlepower discussion is me. I dive and used to use 8xD-cells in my dive light. They got regular full cycles almost every weekend. That’s when I got the blue Tenergy and didn’t find them to be nearly as good as some of the other cells I’ve had in the past. They were highly variable in capacity and charge retention.
Trouble is, you can’t get those cells I did use anymore (Radio Shack NiCads and later NiMh ~4400mA, they lasted years) so I’m not at all sure what is good in the current offerings. I’m not up to date since I’m still coasting on my old D’s for some camping lights, and those are slowly dying. I’ll probably go to AA in the D-shell when I need them in the future since I don’t need the extreme capacity anymore.
Seems you can still get them: RadioShack 5000mAh D NIMH Batteries (2-Pack) $12.62 Amazon They don’t look like the ones I had but they are not over hyping the capacity so they might be OK for what they claim.

Back then I didn’t do cell resistance. I didn’t have the equipment. I just charged and used. I have a good 8-bay MAHA MH-C808M AA – AAA – C – D Battery Charger that is a pretty solid charger on about any NiMh battery but it doesn’t give you any info about the charge at all. I found it on CP forum. [Silverfox] had a huge charger thread there.

I’m glad you checked in about the IMAX chargers. I have an Accucell-6 myself.

EBL doesn’t have a good reputation in AA, so I’d not think the D were any good, but I don’t know. No experience. There are some damning reviews on Amazon with someone that did capacity tests with an Opus.
Just based on reputation and my experience with their AA I’d suspect Maha Powerex Precharged 2 would be good but you’ll pay the same for 2 of them, so a lot more expensive. You can also get them in non-LSD.

I have had (so far) decent results with the Tenergy Centura in C size. I don’t know if that translates into D OK. I don’t have any experience with the Tenergy Premiums.

I don’t know if this is an option for you. They do seem to work. I don’t have extensive experience with them but it’s what I’ll probably use when the last of my D’s die.
5 x Parallel Battery Adapter Holder 1.5V Case Convert 3 AA to 1 D Size
*
Addendum* – just spent more time on that thread. It’s pretty long. Obviously not a straightforward choice. I did get my Blue Centuras on an eBay special. Maybe they spent some quality time in a really hot warehouse or something. Facepalm If I cycled/used them regularly they were OK but they would fall on their face if they sat for very long, like a month. Sad That has always spelled the beginning of the end of a cell to me.

To Air is Human, to Respire….Divine.

Speed4goal
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I don’t have experience with tenergy products but odec d cells have been good to me. I have their aa cells as well. I’ve used the d cells in a baby swing and chair with no problems. Before them I was use 2aa to d adapaters. In them with recharables or alkalines. I still use adapaters for c batteries. But I’m happy with the d cells. Had to buy a adapter to charge them on my opus nihm charger. Its about $28 on amazon. The aa I have probably over 200 cycles on them still going strong

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FlashPilot
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AFAIK, Tenergy hasn’t produced the blue label D cell in several years. They were liquidated by the hundreds on Ebay during a fire sale (the cells had been exposed to high temps during a structure fire) about 3 or 4 years ago. After buying these, several complaints for their high resistance and poor capacity circulated.
I noticed that all-battery.com continually tried to sell the blue top tenergy cells in their email spam mail, so not sure how old their stock is. Ive only purchased from them once (no batteries) and received a faulty protection circuit. They wouldn’t reply to my email so I kept calling until someone answered. I was hammered by an extremely rude man who flatly denied a refund, even though I offered to ship the PC back at my expense. He finally started screaming at me over the phone and I couldn’t understand him. Avoid these screaming lunatics. Just so it stands out to others before they get scammed:

ALL-BATTERY.COM = RAGING SCAM ARTISTS! DO NOT BUY FROM THEM!

When using cells in series, unless the cells are a balanced “matching set”, the lower capacity/higher resistance cells (when in use) will become deplete to a far lower voltage than the stronger cells in the series chain. In laymen’s terms: the lower capacity cells become tortured by the higher capacity cells, which accelerates their deterioration even more. For low amperage discharge applications, this might not become readily apparent. For things, such as high performance incandescent dive lights, the failing cells will cut deeply into the total amount of available run time and may also create unsafe conditions if they become overheated.

Search for the latest capacity tests before you decide to buy more D nimh cells. If a user reports that they seem to work well, IMO, that observation simply isnt good enough to judge the quality, consistency and capacity of the cells. The last time I checked a couple years ago, Tenergys latest offerings of Centura/Premium showed poor quality control with variable capacity and variable resistance. Other comparable cells (once deemed to be of high capacity and consistent performers) also showed a decrease in quality control; with cells showing large capacity and resistance variances. At that point, I gave up my search and continue to use the few Blue Tenergys I still have kicking around from an old Amazon purchase (when these cells were still sold in large number by the reseller and didnt have time to age while sitting in a warehouse). I recycled most of them within the 2nd year of ownership and have about 10 that remain usable in low performance applications (mostly 8 x D cell LED camping lantern).

Zebretta
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FlashPilot wrote:
ALL-BATTERY.COM = RAGING SCAM ARTISTS! DO NOT BUY FROM THEM!

To be honest, they have ignored my request for assistance. So that combined with a set of batteries that appears to have high resistance and never finish charging…..I would have to agree.

Never again.