Anything better than the AA Sanyo 2700's coming out soon?

Seems like Sanyo 2700's have been king of the AA hill forever, though I've never seen anything locally. Best ones available are always Energizer 2500's and Duracell 2650's.

Anything going to surpass the Sanyo 2700's anytime soon?

I kind of doubt it. I think 3100 or 3200 mAh is the ultimate maximum theoretical capacity of a NiMH AA cell but that allows no room at all for separator plates or connections for external electrodes. An actual capacity of 2700 or 2800 mAh is probably about as close as we're ever going to get to this inherent limit.

There are some cells labeled higher, such as the Assia 3000 mAh I purchased on eBay a few weeks ago, but these always fall short of their ratings. Based on my tests though these seem to have an actual capacity of around 2500 to 2550 mAh, perhaps 2600 mAh with a perfect charging algorithm.

I'd personally be very surprised if we ever had a AA NiMH cell with an actual capacity of 3000 mAh. Of course, there may be new chemistries on the horizon which make today's NiMH look puny by comparison.

Well that bites. I'm not sure it's worth ordering the 2700's just for a hair increase in performance over my Sony 2500's. Don't even know how well they do honestly, haven't seen anyone mention them yet. Only the 2300's.

InfidelCastro said:

Well that bites. I'm not sure it's worth ordering the 2700's just for a hair increase in performance over my Sony 2500's. Don't even know how well they do honestly, haven't seen anyone mention them yet. Only the 2300's.

Click to expand...

See this thread.

At a 1 amp discharge rate the Sanyo 2700s give 2569 mAh compared to the Sony 2300s which give only 2068 mAh. No tests of the Sony 2500s but if they scale in proportion to their ratings I would figure they would get around 2250 mAh. The Sanyo 2700s then have only around 14% more capacity. Probably not worth buying unless you really a little more capacity.

A better deal might be the Assia 3000s I purchased on eBay. If you can get them for the opening bid or a little more they cost around $1 per cell shipped. I've measured capacities of around 2515 mAh at 500 mA or 2433 mAh at 2 amps. Only about 5% less capacity than the Sanyo 2700s but one third the price. A set of 8 which I've been cycling seem to be holding up reasonably well. After about 25 cycles at various discharge rates they're still retaining over 98% of their original capacity although the average discharge voltage has dropped by about 0.03 volts.

Actually my Millermods L2P draws about 1.8 amps so it probably makes even less difference. The Energizer or Sony 2500's and Sanyo 2700's would probably be within 5-6% difference.

Hi jtr1962
I can not find these Assia 3000 on ebay!?
Please sent a link
Thank you

jtr1962 said:

See this thread.

At a 1 amp discharge rate the Sanyo 2700s give 2569 mAh compared to the Sony 2300s which give only 2068 mAh. No tests of the Sony 2500s but if they scale in proportion to their ratings I would figure they would get around 2250 mAh. The Sanyo 2700s then have only around 14% more capacity. Probably not worth buying unless you really a little more capacity.

A better deal might be the Assia 3000s I purchased on eBay. If you can get them for the opening bid or a little more they cost around $1 per cell shipped. I've measured capacities of around 2515 mAh at 500 mA or 2433 mAh at 2 amps. Only about 5% less capacity than the Sanyo 2700s but one third the price. A set of 8 which I've been cycling seem to be holding up reasonably well. After about 25 cycles at various discharge rates they're still retaining over 98% of their original capacity although the average discharge voltage has dropped by about 0.03 volts.

Click to expand...

kiely23+ said:

Hi jtr1962
I can not find these Assia 3000 on ebay!?
Please sent a link
Thank you

Click to expand...

You can find them here.

http://cgi.ebay.co.uk/16-3200-mAh-A...hZ022QQcategoryZ14951QQtcZphotoQQcmdZViewItem


any of these reviewed? Or is this a scam?


for 3200 Mah I wouldn't care as much if they were dead in two week with self discharge.

degarb said:

http://cgi.ebay.co.uk/16-3200-mAh-A...hZ022QQcategoryZ14951QQtcZphotoQQcmdZViewItem


any of these reviewed? Or is this a scam?


for 3200 Mah I wouldn't care as much if they were dead in two week with self discharge.

Click to expand...

I'd say that they're a scam.

A lot of stuff on Ebay is fake - including batteries which are usually overrated.

It's unlikely that we'll ever see 3200mAh AA batteries - if we do, it'll most likely be after incremental increases from the current maximum of 2700mAh - i.e. 2800, 2900, etc.

If you want good quality high capacity rechargeable AAs, I'd highly recommend the Maha Powerex 2700mAh. If you don't need the higher capacity over a short period, I would recommend Eneloops or other low self discharge rechargeables...

The biggest issue I have with buying severely over-rated cells from eBay, is that most cheap bargain cells are not consistent from cell to cell. This is a problem as cell consistency in multi-cell devices is a very important factor for cell health. Cells from reputable manufactures are generally all going to be within a couple percent of each-other capacity wise, while cells from "oddball" sources, especially those with huge numbers printed on them, are more apt to have variances of 10-20% or more from cell to cell in capacity and internal resistance.

Cell consistency problems in "bargain" brand NIMH cells is a well known issue, SilverFox may be able to speak more to the issue than I can, but I have enough cheap cells to know they were a waste of my time now.

I'd rather pay $3 for a cell that delivers hundreds of trouble free maintenance free cycles than $1 for a cell that develops problems within the first few dozen cycles.

Currently, for high capacity cells, the Sanyo 2700 is probably the way to go, but as with any high capacity cell, it'll need to be treated with tender loving care, including proper charging and maintenance cycles, in order to maintain decent capacity through it's useful life. Abusing high capacity cells with heavy duty loads seems to be one of the fastest ways to cause their self-discharge issues to get really bad really fast.

Hello Eric,

Well said... A cheap price, or overinflated claim of capacity does not necessarily mean a good value...

Tom

i can confirm that the camellia "2900 mah" are junk.
about 2200 is about their best score after 3 cycles and downhill from there.

Tom,

Well said. I've bought various NiMh cells over the years & as funny as this sounds, the best cells were free.
About 3 or 4 years ago I bought a charger from Thomas Dist. & with the purchase they gave me four Kodak 1700mah cells for free. These have the HR stamp on the bottom. Well they are still working great & have good capacity even after sitting a few months. The Ansmann 2300 & Duracell 2650 that i bought at the same time have all since "crapped" out. So when they say the best things in life are free, i guess they are right!!!!

The current batch of Eneloops (Crown) HR-3UTGA 1.2V. Min. 1,900mAh. are excellent, come off my Sanyo Eneloop Charger at 1.47V. and really perform!

I purchased twelve Sanyo 2700 AA shortly after they were released. Initially all tested between 2500 mAh to 2650 mAh using the break-in mode of the Maha C9000. Within one year of purchase, all failed to hold their charge properly and significantly decreased in capacity. When cycled on the C9000 they got worse, not better. After eighteen months all were useless.

I have purchased about 40 to 50 Eneloop AAs. All exceeded minimum specs at the time of purchase, and all of them continue to give excellent performance after several years.

Better is a subjective term and reflects the opinion of the user. I consider the Eneloop AA batteries much better batteries than the Sanyo 2700. Many CPF contributors have also reported excellent results from Sanyo Eneloops. The latest Eneloop 1500 cycle batteries test even better than the originals. If you value reliability and good value, I strongly suggest you try some Eneloop 1500 cycle AAs.