Go Back   Steve's Digicams Forums > Digicam Help > Batteries or Power Packs

Reply
 
Thread Tools Search this Thread
Old Feb 20, 2005, 1:07 PM   #1
Member
 
Join Date: Dec 2004
Posts: 42
Default

Hi to all, With the nimh now at 2500mah, do you think these companies can produce a AA battery with a compacity higher than 2500mah? If so what would that do for performance of the battery and would you get many recharges out of the batteries if they raised the mah higher than is is now? Where would the ceiling be for the compacity for a nimh AA batery? Thanks for all your opinions.

Dan
dekelsey61 is offline   Reply With Quote
Sponsored Links
Old Feb 20, 2005, 3:44 PM   #2
Senior Member
 
Join Date: Nov 2004
Posts: 216
Default

I don't get what you're trying to say... Something like 12 or 18 months ago, the highest capacity was 2000 mAh, maybe 6 months ago,it was 2300mAh, now its 2500... In the future, the maximum mAh is likely to raise... What will that do ? It will mean that a single charge will last longer in the same digital camera. Aside from that, it should stay the same.
Nicolas is offline   Reply With Quote
Old Feb 22, 2005, 1:49 PM   #3
Junior Member
 
Join Date: Jan 2005
Posts: 20
Default

As Nicolas has stated, a look a recent history tells us that in less than a year, you can just about be sure there will be a NiMH AA with greater capacity than 2500 mAh. Using current NiMH technology, as the capacity has increased, the number of potential effective charges has decreased. The info I've read tells me that a 1800 mAh can be charged effectively close to 1000 times, while the 2500 mAh cells are only good for about 500 charges or so. Of course, much of this has to do with how the batteries are maintained, charged,etc.

It will be interesting to see what happens in the future. The use of digital cameras (primarily) has created a huge demand for rechargeable batteries and I suspect that many companies are spending more R&D dollars than ever before in this area. You never know when they will make a quantum leap in rechargeable technology.

The speed of some of the chargers seems to be getting alot of attention lately as well.

Ialsorecently read of anew developmentin Lithium ion battery technologies. Here's a link to the article:

http://biz.yahoo.com/iw/050210/080729.html

-jeff
tbone-Ike is offline   Reply With Quote
Old Feb 25, 2005, 8:43 PM   #4
Junior Member
 
Join Date: Jul 2003
Posts: 29
Default

The capacity of the NiMH battery will eventually be limited and only refining the physical internal makeupwill allow increased capacity of the AA cells.

Currently, to get larger capacity of cells the manufacturers have been slowing increasing the diameter of the AA cell. Eventually the cell size will meet the size of the cell holder and then the cell won't fit anymore.

You can increase the capacity of anAA cell by increasing the size of the cell. If the manufacturer keeps increasing the celldiameter then eventually the AA cell would be a C cell!

HaveBlue is offline   Reply With Quote
Old Mar 4, 2005, 10:36 AM   #5
Junior Member
 
Join Date: Mar 2005
Posts: 3
Default

I've been following this thread with interest and am intrigued by the idea that manufacturers are simply increasing the size of their batteries to increase the capacity.
I have been using Uniross rechargeable AA batteries for quite a few years now and I have sets of 2100, 2300 and the new 2500mAh AA batteries. I can clearly see an improvement in performance/run times between the different batteries as the stated capacities increase.

I borrowed a friends micrometer to measure the diameter and guess what ? They are all EXACTLY THE SAME SIZE! I then tested a few other brand batteries and yes the diameter increses with capacity.

This leads me to conclude that while some manufacturers may pull these marketing stunts Uniross are actually doing the research and improving the actual power density of the NiMH and bringing genuine improvements to the market place. My research indicates that Uniross have been making rechargeable batteries since the late 1960's and they are widely regarded as the 'Rechargeable Specialists'. I always knew they were good but after this little excercise I'm convinced that they are genuinly excellent. A brand to watch!
Repton is offline   Reply With Quote
Old Mar 29, 2005, 6:50 PM   #6
Senior Member
 
trooplewis's Avatar
 
Join Date: Jan 2005
Posts: 578
Default


Quote:
I then tested a few other brand batteries and yes the diameter increses with capacity.
Could you give a little more info regarding which other brands that you measured, how much they increased in size, and what Mah they were rated for? This is very difficult to believe.

I was under the impression that AA batteries had a standardized length/circumference. Any significant deviations from that would cause compatibility issues in various applications. Do you work for Uniross?
trooplewis is offline   Reply With Quote
Old Apr 2, 2005, 2:26 PM   #7
Member
 
Join Date: May 2003
Posts: 39
Default

Hello - firstly I do not work for uniross but have used their 2000mah 2300mah & 2500mah. I'm pleased with them all and have noticed the increase camera time usage with capacity.

I have also tried other brands such as hanna which seem to last simular to the uniross, with same size cell.

The only noticable difference was the self discharge rate was better with uniross cells.

I have also tried the lithum cells (non rechargable) which lasted slightly longer than 2300mah (on continuous use).

cheers










jenk is offline   Reply With Quote
Old Apr 6, 2005, 11:04 AM   #8
Junior Member
 
Join Date: Jan 2005
Posts: 20
Default



http://www.akkushop.de/product_info....oducts_id=1795

http://www.photoscala.com/node/view/737

-jeff
tbone-Ike is offline   Reply With Quote
Old Apr 30, 2005, 4:26 AM   #9
Junior Member
 
Join Date: Apr 2005
Posts: 29
Default

There is a Russian company, they developed an "Hybrid" Ni-MH batteries. In size of typical AA, it has capacity of 2800-3100Mah, recharge cycle - about 2000, and charging time - 20-30 minutes. The biggest disadvantage is that they are square in shape, so won't fit in AA's place.


A-lex is offline   Reply With Quote
Old May 3, 2005, 9:29 AM   #10
blr
Senior Member
 
Join Date: May 2004
Posts: 339
Default

The capacity of the newer cells is increased mainly by packing more active material into the cell. Also the ratio between the active materialbuilding the positive and negative electrodes is decreasing. Without too much details this lowers the abillity of the cell to recombine the gasses produced during late stages of charging and particularly during overcharging, which results in shorter cycle life.

Also most manufacturers are less and less honest with their ratings the higher the capacity goes. The only manufacturer that is still reasonably close to their nameplate capacity is IMO Sanyo (haven't tested the latest 2500 mAh cells). I have some GP cells rated at 2300 mAh that deliver less dicharge capacity than Sanyo 2100 mAh under identical loads when tested through my Conrad Charge Manager 2010.

I'd take these rating with more than a grain of salt. Given a chance I'd always take the lower capacity cells from a good manufacturer than a ultra high capacity ones with a lower quality.

PS: I don't work for Sanyo
blr is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 2:16 PM.