# RayOVac NiMH AA (NM715)



## UnknownVT (Feb 6, 2008)

I was in a local WalMart last night and saw RayOVac regular (not LSD Hybrids) NiMH rechargeable AA's in new style and packaging -

BUT no where on the package or on the batteries (that I could see) was any indication of capacity - 
the part # on the package was NM715-40P -
this was not much help as it appears doing a web search that NM715 was the part number used for _ALL_ RayOVac NiMH AA - which included the most recent previous version of 2500mAh........

However I visited RayOVac.com and found this pdf spec -

NM715 2100 mAh Nickel Metal Hydride

according to those specs the ones I saw in the new packaging may be *2100mAh*!!

This seems to be a step-_DOWN_ from the previous capacity race in NiMH - 
and maybe that's why there isn't any indication of capacity on either the new packaging or the batteries (at least what I could see through the bubble pack)

I wanted to show a pic - but all my web searches for an image of "RayOVac NM715" showed the older styles from 1800 to 2500mAh.

Anyway - this might be a trend to making lower - but more realistic capacity NiMH rachargeable batteries that may hold their charge longer/better than the "top" capacity 2500mAh?

I have 8 old 1600mAh RayOVac NiMH - bought when they first came out circa 2001(?) Which have had pretty extensive use in my digicam at the time for over 21 months cycled on average once/week per set of 4.

Now they have been relegated to low critical use - eg: set of 4 in the digicam I use for my beamshots and a pair in an electric toothbrush (obviously used daily) - they still seemed to hold their charge well enough that I only need to charge them between 2-3 months - pretty good considering they are about 7 years old and heavily used for 21 months (prob about 100 cycles during that time) ......

The lower more conservative capacity may seem like bad news - 
but the good news was the price - at that local WalMart they were a mere *$5.97* for a 4 pack, 
if I didn't already have a set of 2500mAh and 4 sets of 4 LSD AAs (8x eneloops and 8x Kodaks) I would have bought them.......


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## Black Rose (Mar 11, 2008)

I picked up a couple of these new packs last fall. Since the rating was not on the packaging, I contacted Rayovac.

They sent me a document that said that they were 2000 mAh cells.

I took a closer look at the embedded info in the document that Rayovac sent me and that document was created in 2005, which probably was for the gold coloured batteries.

I then looked at the security info in the AA PDF, and it was created in September 2007, so it looks like the batteries I picked up are actually 2100 mAh.

In my case this is a slight step up as all the other non LSD Rayovac NiMh AA cells that I have acquired in the last year are all 2000 mAh.


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## snakebite (Mar 11, 2008)

testing some aaa like them now.
they seem to come in around 850mah on my c9000
even at a 1000 ma discharge!
these might be better than i suspected.
why not mark them with the capacity?
are we the only ones who care?


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## Black Rose (Mar 31, 2008)

I just received a response from Rayovac about the batteries talked about in this thread.

According to the Rayovac rep, the NM715-40P labeled package (green/chrome/black battery labels) are actually 1400 mAh cells 

I was previously told by Rayovac that they were 2000 mAh cells...no wonder I thought they were showing a huge capacity loss with my Maha C9000 

The Rayovac rep also told me the link that UnknownVT posted is the data sheet for the Hybrid AA cells. Guess I can take these batteries out of the recycling pile.


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## UnknownVT (Mar 31, 2008)

Black Rose said:


> She also told me the link that UnknownVT posted is the data sheet for the Hybrid AA cells.


 
I do know the difference between plain NiMH and the RoV Hybrid LSDs.

Have you actually even bothered to click on the pdf datasheet I linked?

NM715 2100 mAh Nickel Metal Hydride

here's the actual url -

http://rayovac.com/technical/pdfs/NM715_2100MAH.pdf

Notice the RayOVac and the NM715_2100MAH of the document?

Here's a crop from that pdf datasheet -






Please note the " *Name: NM715 2100 mAh NICKEL METAL HYDRIDE* " - top right corner


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## Black Rose (Mar 31, 2008)

Don't shoot the messenger, just passing along what I was told.

And yes, I did open it. I also have a copy of it stored on my hard drive.

I included the link you originally posted when I contacted them. That's what she responded with. Think I'll send her another message about this.


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## UnknownVT (Mar 31, 2008)

Black Rose said:


> And yes, I did open it. I also have a copy of it stored on my hard drive.


 
So, does the pdf document say _ANY_where about being Hybrids or LSD (Low Self-Discharge)?

And I think you also checked the date of creation of that pdf -
using pdf Analyzer mine says "12.09.2007 / 15:45:47" - I think that's in European date format 
- which is then Sept/12/2007 (agreeing with your own findings) 
- so the pdf document is fairly recent - 
coinciding with the appearance of these new NM715 AA that I reported about.

Hybrid LSD have a RoV part number of *LD*715 for AAs - 
same number but different alphabetical prefix


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## Black Rose (Mar 31, 2008)

UnknownVT said:


> So, does the pdf document say _ANY_where about being Hybrids or LSD (Low Self-Discharge)?


Nope. I tried to see if I could browse their tech site to get the data sheet on the LD715, but so far no luck.



> Hybrid LSD have a RoV part number of *LD*715 for AAs -
> same number but different alphabetical prefix


I sent them another e-mail about the fact that the PDF stated NM715 in it and that the Hybrids use product/part number of LD715.

I really don't know if it'll do any good though....I've talked with two different Rayovac reps and received two different answers that do not match the NM715 data sheet.


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## UnknownVT (Mar 31, 2008)

Black Rose said:


> I've talked with two different Rayovac reps and received two different answers that do not match the NM715 data sheet.


 
There you go... 
they have to be _*TWICE*_ as versatile as me - 
since I've only been giving the same single piece of information......

If it's of any (non-)help - RayOVac do have another website and the Hybrids are listed there -

http://www.rayovacindustrial.com/products_batt_hybrid.shtml

BUT please be careful and do not be hasty - 
as I opened the pdf 

LD715-4 Low Discharge AA NiMH carded 4 pack SPECS (link)

and that pdf document may be a plain (non-LSD) NiMH 2000mAh -
I did a search for Hybrid, LD, Low discharge and low self discharge in that document and could not find anything.
crop from that pdf document - which is supposed to be Hybrid Specs (it is NOT) -





so much for RoV clarity.


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## Mr Happy (Mar 31, 2008)

You may not find any reference to low self-discharge in a data sheet. For example, here is the Sanyo data sheet for the AA size Eneloop, and from reading it you wouldn't know it was different from any other NiMH:

http://www.eneloop.info/uploads/media/Datasheet_-_HR-3UTG_01.pdf


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## UnknownVT (Mar 31, 2008)

Mr Happy said:


> You may not find any reference to low self-discharge in a data sheet. For example, here is the Sanyo data sheet for the AA size Eneloop, and from reading it you wouldn't know it was different from any other NiMH:
> http://www.eneloop.info/uploads/media/Datasheet_-_HR-3UTG_01.pdf


 
The main difference is that the eneloop datasheet does have clearly its part # HR-3UTG

The RoV datasheet does NOT seem to have a clear part/model number - that's why I tried to search on those terms to confirm if it were for the Hybrid.

Other discreprency that gave rise to my doubts about that document being for Hybrids -
That RoV pdf datasheet has a spec'd capacity of *2000mAh* -
" _*Ratings* _
_1.1 Ratings After Charge _
_1.1.1 Nominal Operating Voltage 1.24 volt (discharged at 0.2ItA to 1.0 V at 20 ± 5°C) _
_1.1.2 Nominal (C5) Capacity 2000 mAh _
_1.1.3 Minimum Individual (C5) Capacity 1900 mAh_ " 

whereas the RoV Hybrid AA label - claim *2100mAh*


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## Black Rose (Mar 31, 2008)

Grabbed the AA & AAA spec sheets from the other site. Thanks.

Interesting reading, especially the tests they put the cells through.


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## UnknownVT (Apr 1, 2008)

Black Rose said:


> Grabbed the AA & AAA spec sheets from the other site.


 
Those pdf's are supposed to be datasheets for the Hybrid LSDs - take the one for the LD715 (AA) - 
did you notice the revision panel on the bottom of every page? 






the revision date is 09/12/05 and that's for revision C ....

eneloops - the first LSDs - were announced Nov/2/2005 - 
and this RayOVac pdf spec/document on revision C was produced on 09/12/05 - 
so along with the other discreprencies I am very dubious that it is actually for the Hybrid LSD........


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## SilverFox (Apr 1, 2008)

Hello Vincent,

The specification you posted in post #13, is very interesting.

Did you happen to notice Section 4.4 Cycle Life Testing?

Since there has been a lot of previous discussions about slow versus fast charging, I took some time to review Ray O Vac's test results in this area. I found it very interesting that their testing shows around a 20% increase in cycle life (down to 80%) charging at 1C versus charging at 0.1C.

Now this improvement may not be entirely due to charge rates. You will notice that the discharge rates are also different. Cycle life is also effected by depth of discharge, so it may be that discharging at 0.2C down to 1.0 volts is a deeper discharge than discharging at 1C down to 0.9 volts. 

I have seen references by Sanyo and GP about using accelerated life cycle testing, but I have not seen the results laid out side by side.

I wonder if charging and discharging at 0.5C gives you more, or less cycle life...

Tom


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## UnknownVT (Apr 1, 2008)

SilverFox said:


> Did you happen to notice Section 4.4 Cycle Life Testing?
> Since there has been a lot of previous discussions about slow versus fast charging, I took some time to review Ray O Vac's test results in this area. I found it very interesting that their testing shows around a 20% increase in cycle life (down to 80%) charging at 1C versus charging at 0.1C.
> Now this improvement may not be entirely due to charge rates. You will notice that the discharge rates are also different. Cycle life is also effected by depth of discharge, so it may be that discharging at 0.2C down to 1.0 volts is a deeper discharge than discharging at 1C down to 0.9 volts.


 
No, actually I depend on the more knowledgeable like yourself to point out these things to me  :thumbsup:

Here is that relevant section (it spanned across two pages - I merged the parts)





I deliberately left in the following section - "4.7" - 
so what happened to sections 4.5 and 4.6?

The above is supposed to be for the RoV Hybrid AA LSD - but as I said I have doubts that it is - due to several discreprencies and the fact that revision C is 9/12/05 - when the first LSD - eneloop - was only announced on Nov/2/2005! - so were RoV that far ahead of the game that they were already on revision C of this document - or is it remotely possible that this pdf is _NOT_ for the Hybrid LSD? - I leave it for anyone to draw their own conclusions.

Getting back on topic about the NM715 - plain (non-LSD) NiMH batteries but staying with the life cycle - on the RoV_Industrial page on Rechargeables

NM715-4 Rechargeable AA NiMH Carded 4 Pack SPECS (link)
the url: 
http://www.rayovacindustrial.com/assets/pdf/marketing_data_sheets/NM715_S4001738.pdf
(for the more sharp-eyed - the photos of the battery packs are for the previous/older 2500mAh NiMH which unfortunately also have the part # NM715)

Please note the correct part # of NM715 (both in the url and the pdf document) - the plain (non-LSD) NiMH AA that's in the thread title -





I'll leave it for the more knowledgeable to comment on this.


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## Mr Happy (Apr 1, 2008)

Based on that chart, I'd feel that the effective life is only 100-150 cycles. I know that 80% of 1900 is about 1500, but I'd rather it didn't drop that far, that quickly.

It would be interesting to compare a similar chart for Eneloops if anybody has come across one.


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## SilverFox (Apr 1, 2008)

Hello Mr Happy,

That graph makes the 150 cycles I got on the 15 minute charger not look so bad...

Tom


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## UnknownVT (Apr 1, 2008)

Mr Happy said:


> It would be interesting to compare a similar chart for Eneloops if anybody has come across one.


 
Can't find one on the eneloop -

But Sanyo has this pdf on their TwinCell NiMH dating back to 2001-2





and Panasonic NiMH pdf -





again I leave it for the more knowledgeable to comment.


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## Bones (Apr 2, 2008)

UnknownVT said:


> Those pdf's are supposed to be datasheets for the Hybrid LSDs - take the one for the LD715 (AA) -
> did you notice the revision panel on the bottom of every page?
> 
> 
> ...



I agree that it is highly unlikely that the RayOvac .PDF report numbered S4000965 is regarding their Hybrid.

Part 4.8, entitled _Charge Capacity Retention_, only requires the cell to retain 75% of its capacity after 28 days in storage at 20° Celsius.

Surely, they would have set this specification considerably higher if it was intended for their low self-discharge cell.


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## Bones (Apr 2, 2008)

SilverFox said:


> Hello Vincent,
> 
> The specification you posted in post #13, is very interesting.
> 
> ...



Yes, it is very interesting SilverFox.

However, because the document is first and foremost a report on achieving target specifications, I think the only facts that can be extropolated with any certainty is that the targets were met.

Accordingly, I don't think you can properly describe it as test on cycle life since it doesn't include the actual results of their tests.

For all we know, the targets could have been exceeded, and even grossly exceeded, in any of the reported catagories.

Incidentally, when reviewing the specifications, I noted that the target capacity for charge acceptance at 1C at 20° Celsius is set at only 95% of the cells specified capacity.

So, you have one specification on cycle life derived from a series of timed 16 hour charges at .1C, which we know overcharges the cell, being compared with another specification on cycle life derived from a series of charges at 1C which are only required to charge the cell to 95% of its specified capacity.

Without over-speculating on why the specifications were set as they were, it does seem to be another indication that this report is not conducive to reaching any conclusions on which charge rate maximizes cycle life.

It seems to me that this comparison can only be fairly drawn when the cells are being charged to the same capacity with both the slower and the faster charge rates.


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## Mr Happy (Apr 2, 2008)

Bones said:


> It seems to me that this comparison can only be fairly drawn when the cells are being charged to the same capacity with both the slower and the faster charge rates.


I think this is not likely to happen. You always find that a timed standard charge at 0.1C puts more charge into a cell than a 1C charge with -dV termination. It comes down to the underlying chemistry and physics of how the cells work.


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## Bones (Apr 2, 2008)

Mr Happy said:


> I think this is not likely to happen. You always find that a timed standard charge at 0.1C puts more charge into a cell than a 1C charge with -dV termination. It comes down to the underlying chemistry and physics of how the cells work.



I agree.

In fact, my concern with using the referenced specifications for extropolating whether a slow charge or a fast charge will better maximize cycle life is based, in part, on the fact that these two protocols were being used.

The other part of my concern is not only that the series of slow charges used in the specification overcharged the cell, but that the series of fast charges being used were only required to charge the cell to 95% of its specified capacity.

In other words, the comparison on cycle life is being derived from a series of deliberate overcharges with respect to the slow charge rate, and a series of apparent undercharges with respect to the fast charge rate.


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## SilverFox (Apr 3, 2008)

Hello Bones,

I view the document as a performance specification that was generated to insure quality control over their production lines. If a buyer is interested in making sure of the quality of the cells he is buying, paperwork like this is generated to track the performance of the various batches of cells.

It also includes the IEC and JIS standards that battery manufacturers use to rate their cells, and check their performance.

The interesting part of the cycle testing results is that it seems that the required minimum 500 cycles was not being obtained using the IEC and JIS “standard” charge and discharge procedure. It looks like they took some “liberties” with the IEC accelerated life cycle test procedure and came up with their own version. 

I think it addresses a problem they were having with cycle life and I give them points for including the “standard” charge/discharge cycle life data. 

If I were a buyer, I would find their “adjustments” to the accelerated cycle testing standards acceptable. They changed a couple of things, but pretty much followed the standard. If I were looking at several different brands, I would compare the standard cycle test results between the various battery manufacturers while realizing that the standard call for either passing the standard cycle test, or the accelerated cycle test. You don’t have to pass both.

The charge acceptance portion is a little harder to understand. By definition, both cells are fully charged. The standard charge calls for charging at 0.1C for 16 hours. The battery manufacture states that when rapid charging (1C) the cell is fully charged when the –dV falls in the range of 3 – 8 mV. Since in both cases the cells are fully charged, and the discharge rate is the same, there should be no difference in discharge capacity. 

The 95% listing in cycle testing is a bit different. Cells have internal resistance. When you discharge at higher rates, the internal resistance converts some of the capacity of the cell to heat, and it is lost. Based on the difference in discharge rates used in the different tests (0.2C versus 1.0C) the capacity is adjusted to reveal the effect of the cells internal resistance.

Once again the cell is fully charged, according to the manufacturer, but the higher discharge rate involves some losses. In this case, they are saying that the internal resistance of the cell will only result in a maximum of 5% loss in capacity at a 1C discharge rate.

I think your assumption that the 1C charge is only charging the cells to 95% is wrong. I think the 5% loss in discharge capacity has to do with the heat losses involved with discharging at higher rates. I think the results presented in the cycle testing tables are valid and do represent how these cells respond to fast versus slow charging. I have observed this with my own cells, and it is nice to see it presented here.

I also think I understand your concerns, but when testing you always start with an examination of the standards involved. The IEC standard actually lists 90% as the minimum capacity when discharging at 1C, so this performance specification actually exceeds the standard. Some day I hope to be able to do some testing in this area, but for now, it is nice to review someone else’s data on this.

Tom


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## Mr Happy (Apr 3, 2008)

SilverFox said:


> The charge acceptance portion is a little harder to understand. By definition, both cells are fully charged. The standard charge calls for charging at 0.1C for 16 hours. The battery manufacture states that when rapid charging (1C) the cell is fully charged when the –dV falls in the range of 3 – 8 mV. Since in both cases the cells are fully charged, and the discharge rate is the same, there should be no difference in discharge capacity.


I think this is not quite the case.

Consider it this way. During charging it is observed that in the beginning almost 100% of the supplied energy is stored in the cell and very little is converted to heat. As charging progresses, the ability to store charge gradually reduces until near the end of charging most of the energy is being converted to heat and very little is being stored. At this time the cell temperature starts a rapid rise and the rise in cell temperature leads to the drop in voltage seen as the -dV termination signal. However, when the -dV signal is seen, _some_ of the supplied energy is still being stored; the cell has not quite reached 100% of its maximum storage capacity. In spite of this, the rise in temperature says it's time to stop charging at such a high rate or the cell will get too hot.

Now with the 0.1C standard charge over 16 hours, this premature end of charging doesn't happen. After about 10 hours and up to 16 hours, more and more of the supplied 0.1C charge is being lost as heat and less and less is being stored. The cell doesn't mind this since the charge rate is low, the amount of heat is small, and the temperature rise is not excessive. Even so, drip by drip, some extra charge is still being stored and the cell is being pushed up to the maximum energy storage that it is capable of.

So in my understanding, when a manufacturer says a cell is "fully charged" they mean it is time to stop charging. When it is time to stop charging depends on the charging protocol being applied; whether by time, by voltage or by temperature. Fully charged is not always the same; it means "charged up as much as the cell can take under these charging conditions".


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## Bones (Apr 4, 2008)

SilverFox said:


> Hello Bones,
> ....



Hello SilverFox,

Thank you for your very detailed response to the concerns I raised respecting your first post in this regard.

You covered a lot of ground, so rather than quote the whole response here, I will just provide a link to the full text, and quote only the portions being immediately addressed.

I would like to start by reiterating my primary concern with this dialogue in general:



Bones said:


> ...
> However, because the document is first and foremost a report on achieving target specifications, I think the only facts that can be extropolated with any certainty is that the targets were met.
> ....



Unless I completely overlooked something in the specifications, I think my concern can exemplified with this portion of your first post:



SilverFox said:


> ...
> Did you happen to notice Section 4.4 Cycle Life Testing?
> 
> Since there has been a lot of previous discussions about slow versus fast charging, I took some time to review Ray O Vac's test results in this area. I found it very interesting that their testing shows around a 20% increase in cycle life (down to 80%) charging at 1C versus charging at 0.1C.
> ...



I have examined the document very carefully, and failed to find the test results you referenced, so it would be appreciated if you could point them out.

The referenced specifications:

http://www.rayovacindustrial.com ... S4000965.pdf


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## UnknownVT (Apr 4, 2008)

Bones said:


> I have examined the document very carefully, and failed to find the test results you referenced, so it would be appreciated if you could point them out.


 
I'm not SilverFox - but when he posted that about the 20% increase in cycle life - 
I replied with the relevant section of the pdf (in post #*15* ) - 
what I read was -

4.4.1 Standard Cycle Life 
Charge: 0.1ItA for 16 Hours, (section 1.2) 
Rest: 30 minutes between each charge and discharge half cycle 
Discharge: 0.2ItA to a 1.0 end point voltage 
_Minimum average capacity at cycle *250*: 80% of initial average capacity_ 

4.4.2 Consumer Cycle Life 
Charge: 1ItA to a –dv = 3 - 6 mv cutoff, (section 1.3)
Rest: 30 minutes between each charge and discharge half cycle 
Discharge: 1ItA to a 0.90 end point voltage 
_Minimum average capacity at cycle *300*: 80% of initial average capacity_

I put the relevant parts in _Italics_ - for the 80% down - 
please notice the cycles are different I have put those in *Bold* - 
250 for the standard and 300 for the consumer cycle life -
that is a 20% increase in cyles from 250 to 300.


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## Bones (Apr 4, 2008)

UnknownVT said:


> I'm not SilverFox -
> ...



Thanks for the response UnknownVT.

I think I will just characterize the extrapolation of a case for fast charging from the available data as interesting, and leave it at that ...


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## SilverFox (Apr 4, 2008)

Hello Bones,

Let me see if I can clearify things a little.

This performance specification is designed to check each lot of cells coming from a shifts production of batteries. Out of the hundreds of thousands of cells produced each shift, a representative sample of cells are taken for testing.

A statistical revealant number of cells are used for each test listed in the performance specification. The number of failures allowed for each test are listed in the various standards.

The performance specification is basically a "go" "no go " test. If the samples meet the specification, the lot is accepted. If they don't the lot is rejected.

You may think that in order to make a comparison you need to check the exact numbers that the tests produced, but I feel that you can get a very good idea of what is going on by simply reviewing the performance specification.

Instead of wading through hundreds of thousands of individual test points, the performance specification acts like a summary of the data.

When a company produces a performance specification that their product meets, and this is evidenced by the sales of their product, I refer to the numbers produced in the performance specification as test results.

Tom


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## Bones (Apr 5, 2008)

SilverFox said:


> Hello Bones,
> 
> Let me see if I can clearify things a little.
> ...
> I refer to the numbers produced in the performance specification as test results.



I suppose it does go hand in hand with referring to a manufacturers use of a 1C charge and discharge rate in their performance specifications as a 'recommendation' to charge at 1C.


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## snakebite (Sep 1, 2008)

just did a 4 pack of these.tested on c9000
avg around 1200 mah after 3 cycles.
nm715-40p from walmart this weekend.
is this a bad joke?
no wonder these are cheap and no capacity listed.


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## Black Rose (Sep 1, 2008)

Were those the green/chrome/black ones?

I have 8 of those and they all test in the mid 1300 mAh range on my C9000. The Rayovac rep I talked to about them said they were 1400 mAh cells. When I bought them I assumed they were 2100 mAh cells since there was no capacity listed on the cells or the packages.


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## Eugene (Sep 2, 2008)

I have a couple packs of RayoVac 2000mAh (gold/black). They are a few years old now and earlier this year when I got my C9000 I tested them out, all were less than 80% of the 2000mAh stated capacity and I know they didn't have that many cycles on them. I had bought them for our digicam and after just a few cycles they appeard to not be holding any kind of a charge, turns out the rayovac charger I was using was crap (PS4) so it was replaced by a maha and the batteries cycled a few times and put back to use in kid toys. These were all purchased in 2004. I compared them to Sanyo Twicells purchased in 1999-2001 which are all testing at 75-85% capaity despite being twice as old.
The one thing I have leraned is I won't be buying any rayovac products anymore.


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## frasera (Nov 5, 2008)

Black Rose said:


> Were those the green/chrome/black ones?
> 
> I have 8 of those and they all test in the mid 1300 mAh range on my C9000. The Rayovac rep I talked to about them said they were 1400 mAh cells. When I bought them I assumed they were 2100 mAh cells since there was no capacity listed on the cells or the packages.



egads, lesson learned. i bought a set at wallyworld cuz it was so cheap! i was a bit dubious at the lack of rating, but i thought by now the minimum would be 2000mAh, guess not. ah well candlepower got me answers better than google lol


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## gregoryh (Nov 5, 2008)

I don't think we ever see the manufacturer's numbers on capacity due to the fact that they test capacity at .1C discharge and most of us , at least myself use well above that. I use 500ma on my MAHA. That being the case, the extra current should make the battery show the 1.0 volt minimum before you would see it at .1C discharge rate, hence the charger would terminate the discharge and some mah would would left in the battery. That being said, the difference would only be 100 to maybe 200 mah . 
True or not true?
Greg


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## Black Rose (Nov 5, 2008)

I have a couple sets of those (green/chrome/black) that I am doing self discharge tests on.

The 30 day test will be performed this weekend and the 60 day test a month after that.

The one advantage of the 1400 mAh cells is that they won't self discharge as fast as higher capacity cells.


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## Black Rose (Nov 9, 2008)

30 day self discharge tests on Rayovac 1400 mAh AA NiMh rechargeables (green/chrome/black).


```
Initial capacity    Capacity after 30 days    Capacity loss 
1384 mAh              1133 mAh                 18.14%
1346 mAh              1076 mAh                 20.06%
```
 
They seem to be self discharging less than the 30% per month figure I'e seen mentioned, but the lower capacity of the cells really didn't reduce the self discharge that much.

I have a second set of these sitting for a 60 day test. I expect those should be 40 to 50% depleted by this time next month.


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## SilverFox (Nov 9, 2008)

Hello Black Rose,

I am not sure where you came up with the 30% per month figure, but your cells seem to be self discharging at around 0.7% per day. This is a normal rate for healthy NiMh cells.

At the end of 60 days, I would guess that your cells should have around 66% of their initial capacity left.

Tom


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## TerrificInTahoma (Nov 11, 2008)

Hello All:

I also was confused by the packaging , but I decided NOT to Buy them. The Wal-mart store in my town has them available to CAD$6.97 , but that is half the price of comparable AA Cells. 

I then asked the store 'Assistants' form the Camera and Battery department if they could fid the information on the capacity from their order lists.

No luck.

Today (Nov 11, 2008) I telephoned Wal-Mart Customer service who directed me to Ray-O-Vac (Spectrum Brands in Canada) Consumer Line at 800-268-0425.

After the normal Press 1 for english press 2 for quebec(Couldn't they just direct the calls by area code to French ONLY speakers, but I digress), then speak with a customer service rep.

She says the NM714-4P Model type of AA batteries are at 1400 mAH, and when asked why they do not include this information on the packaing, she replied "to save on the cost of re-printing if they improve the batteries to 1500 or 1600 mAh".

I asked about this and the rep said that Wal-Mart does not buy the 2100 mAH or 2400 mAH Batteries from them.

I replied thank you , and now am in the pocess of launching a letter campaign to the State officials for Commerce. :laughing:

It is Illegal in Canada to sell products without certian information on the packaging. The Capacity of something may be one of those items.

Will keep you posted as to the results.
-TerrificInTahoma


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## cave dave (Nov 11, 2008)

Its called Walmart: "*always low prices*", not always reasonable good deals.

I've observed shoppers in the battery isle and there are only two kinds. The Duracell are the best, cost not a problem kind and the whats the lowest price for a 4 pk on the shelf kind.

I have never, I repeat never seen somebody flip over a package and read the info on the back, and probably never will till they install a mirror in the battery section.


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## frasera (Nov 12, 2008)

new development on cheap battteries at walmart.

they now have "ECOtrends"

the 4 pack AAA is $5.66
but this time they state mah rating of 900.

the AA is $7.50ish i don't remember exactly cuz i didn't buy that one. but it states rating of 2100mah.

on the back it says its a division of Sakar 
www.sakar.com

as for the "eco" thing, it claims ROHS compliance. whether this is different i dunno.


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## frasera (Nov 13, 2008)

seems they sell a solar charger.
no word on charge time. gotta figure it takes days.
http://www.walmart.com/catalog/product.do?product_id=10401079

but it seems like the aaa's are ignored by my duracell 15 minute charger. not sure why the contact dimensions arent any different from my others


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## Bonky (Nov 13, 2008)

The Duracell 15 minute charger is notoriously fickle. I had to return mine when I found it wouldn't charge anything but Duracell cells.

Get a La Cross charger.


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## frasera (Nov 13, 2008)

er, well...

i didn't mean it that way. the duracell rejects cells that have too high internal resistance either because they are old or junky and cannot be charged at such a fast rate without excessive heat. i've been able to charge many brands without fail in the 15 minute from enloops to rayovacs, it has no need for "duracell" brand batteries at all, perhaps you tried charging old cells? i had some older off brand cells rejected. but its obvious when that happens because the light flashes immediately to signal rejection.

nothing happens at all with the aaa ecotrends which is just odd. no sign of life at all.


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## Bonky (Nov 13, 2008)

have you tried charging them very slowly on another charger, eg. ~150ma for a few hours first? Sometimes when they drop too low in voltage they need to be very slow charged just to get them to the point where normal charging will do anything.

Again, all this is guesswork. If you drop $35 you can get a charger that will tell you all this stuff.


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## aeroshep1 (Nov 13, 2008)

on the back it says its a division of Sakar


Sakar is the company that makes those really crappy DIGITAL brand batteries and chargers. The batteries could only handle a few charges, and could not hold a load at all. These are probably the same batteries in another wrapper. Also the 2000MAH's never teste above 1350 on th bc 900.


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## Bonky (Nov 14, 2008)

honestly when it comes to batteries, there are no 'deals'.. ie, no getting away with crap brands that are as good as the real thing. Unlike, say, coffee makers, which are all pretty much the same no matter who makes 'em.

I'd go with the big brands recommended on other CPF threads.


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## frasera (Nov 15, 2008)

Bonky said:


> have you tried charging them very slowly on another charger, eg. ~150ma for a few hours first? Sometimes when they drop too low in voltage they need to be very slow charged just to get them to the point where normal charging will do anything.
> 
> Again, all this is guesswork. If you drop $35 you can get a charger that will tell you all this stuff.




heh i charged them on a slow cheap charger. haven't run them through yet to be able to test that. guess i'll drain them a bit and see if it does anything.


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## Bonky (Nov 15, 2008)

you may have to cycle them a few times. My g/f nearly ruined a set of Nimhs awhile back. They were <0.5v, I charged them on a slow charger and then discharged them on my Lacrosse.. it said they were at 100mah. Another cycle got them up to 500mah and after a couple more they were back at 2500 and seem to be holding steady.

Point: you may need to recondition them which could take several cycles of charge and discharge.


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## Darkseid001 (Jan 16, 2009)

TerrificInTahoma said:


> Today (Nov 11, 2008) I telephoned Wal-Mart Customer service who directed me to Ray-O-Vac (Spectrum Brands in Canada) Consumer Line at 800-268-0425.
> After the normal Press 1 for english press 2 for quebec(Couldn't they just direct the calls by area code to French ONLY speakers, but I digress), then speak with a customer service rep.
> She says the NM714-4P Model type of AA batteries are at 1400 mAH, and when asked why they do not include this information on the packaing, she replied "to save on the cost of re-printing if they improve the batteries to 1500 or 1600 mAh".
> 
> -TerrificInTahoma


Do NOT buy these CRAP-O-VACS. I made the mistake of purchasing these Rayovac NM715-8OP batteries and they are by far the lamest NiMH batteries I have ever seen next to Energizer NiMH that come with an unbelievably high self discharge rate. Just for confirmation I am talking about the green/chrome/black coloured rayovacs. I have tested these batteries multiple times with my MAHA C9000 at different charge/discharge rates and was in shock to see that they were only 1400mAH. After I tested them the first time and got only 1383mAh I was thinking that maybe I did the test wrong so I repeated it at different rates and still the results all suggest that these batteries are 1400mAh. I proceeded to check them with the LaCrosse BC-900 which again confirmed the 1400mAh. 

I am sorry to report to all of you who believe in the data sheets provided by Rayovac but the company is clearly misleading and I would go so far as to call them liars based on the testimonies given by so many of you who called them to inquire. These green/chrome/black batteries do not have the capacity printed on them simply because the company is ashamed to be producing such crappy products when the current standard for non-LSD NiMH is around 2500mAh. Therefore they resort to misleading consumers to get sales, this is illegal and those batteries should be banned. I wish people would also take this matter up with walmart and petition them to stop selling misleading products like this. I mean seriously who would buy these if they had 1400mAH printed on them? The only time I would consider purchasing such low capacity batteries is for hobby projects and I did solder 2 of these to make a battery pack for a cordless phone instead of buying toxic NiCD original replacements.

My advice is to pass the word on to everyone you know and even urge people to make complaints to your local consumer affairs office to get these crappy misleading batteries banned.


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## frasera (Jan 29, 2009)

yea its a bit dodgy. no one would buy them if labeled correctly thats for sure.

walmart did have some slightly more expensive ecotrends batteries that did have ratings. i didn't see them back on the shelf last time i went. 7-8 dollars instead of 6 dollar for rayovac. i wonder how honest their ratings were?
seems no ones tested or reported on them lately ah well heh


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## snakebite (Mar 8, 2009)

now for the good.
these cheap green/silver rayovacs have lower internal resistance then anything else i have on hand.they flash amp at 15.5a on my fluke 77bn.
eneloops,duraloops,kodak lsd,and sanyo made kodak 2500 dont even come close.next best are eneloop/duraloop at about 9.
i hotrodded an htx-202 2m ht when i got some specially binned 2sc1971 transistors .this hand held radio does 11w at 12v.
i built a pack out of a delcom marine pack that had room for 20 cells.
built it 10s 2p with these rayovac "greenies".
11w on batteries measured on a bird 43 is hot for a handheld rig.
this will be the ultimate test for these cells as not only will they get pounded when discharged they will be charged in a drop in that can charge at 2.5a and terminates on temp.
and the aaa cells came in around 850mah.
i just rebuilt the pack on my th-31at 220 rig with them. 
used some in my black&decker screwdrivers that i run on 4.8v rather than 2.4. they have held up well to the high drain rate and the dumb charger.


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## Russel (Mar 9, 2009)

snakebite said:


> ...i hotrodded an htx-202 2m ht when i got some specially binned 2sc1971 transistors .this hand held radio does 11w at 12v.
> i built a pack out of a delcom marine pack that had room for 20 cells.
> built it 10s 2p with these rayovac "greenies".
> 11w on batteries measured on a bird 43 is hot for a handheld rig.


 
Sounds like you need two hands for your HT now...


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