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Technical Editor Margery Conner's PowerSource streams the latest developments in electronic power design and related technologies. Follow Margery on Twitter at: http://twitter.com/margeryc.

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Monday, March 23, 2009

What’s the best rechargeable battery for your digital camera?

Mar 23 2009 10:41AM | Permalink |Comments (15) |

Wired magazine (print) tested 4 popular batteries and their chargers with a Canon PowerShot A2000. Love that recharge time on the Energizers. (I tried to find a link to this online, but no luck…)

Battery	Photos/charge	Recharge time	Price
Duracell 2650 mAh	1,377	620 min.	$13; (2AA batteries, charger)
UltraLast Green Pre-charged Rechargables	781	90 min.	$30; (4AA, charger)
Sanyo Eneloop	759	150 min.	$25; 2AA, charger)
Energizer 2450 mAh	693	13 min.	$33; 2AA and 2AAA, charger)

Related entries in: Battery Power | Power Sources/Controllers | Power supplies |

Reader Comments

at 3/23/2009 5:51:55 PM, Meredith Poor said:
One of the more interesting reads in the Electric RC Aircraft magazines was the games the battery and battery pack manufacturers would play with naming. The sub-C cells they used might be labeled 4300 but they might have 3900 Mah when tested by the raters.
~~~
If you go to Walmart or Costco and look carefully at the C or D NiMH batteries you realize they're simply AA cells in bigger containers: 2700 MAh for AA, 2700 MAh for C, 2700 MAh for D. If you go to the battery websites and look for GP Batteries you find C cells at 3500 MAh and D cells at 9000 MAh. I've been able to find '2700' from every one of the manufacturers listed in the table, so I suspect that the Wired test wasn't particularly rigorous or scientific.
~~~
If you're building robots, you pay a lot of attention to batteries. What you find in the retail marketplace is an embarassment, to put it mildly.

at 3/24/2009 12:55:36 AM, melodie.chia said:
I thought of using a Sony rechargeable battery. Ive heard alot of people saying that it is good. What do you think? WHich brand would you recommend?
www.ardenmktg.com

at 3/24/2009 1:22:38 PM, Chris PE said:
There is no smallest doubt that in AA category and AAA category Duracells are the best.The trick is in the charger.The more elaborate one , the better.Good chargers have seperate charging circuits for EACH battery and work perfectly. I found one in Wallmart with indicators of charging for every battery.I agree with Meredith that C and D are just AA in a larger case.We did discuss it before when we talked about "current density".A good MiNH C should be at least 4000mAh and D 9-10000mAh.If it''s not on a box a rule of thumb is weight.NimH "D" is really heavy.As far as AA I recommend Duracell (NOT PRECHARGED made in China - I had 3 bad out of 8 and Duracell sent me coupons for a discount from another pourchase).The regular ones are made in Japan, I use them all the time and I often take 500-600 pictures with my Fuji Finepix S9100Z with flash. Precharged are not as great as they were made to be.The regular ones - 2650mAh are awesome and can be used in a variety of devices.Just remember , when you don''t use them they will lose some capccitance or just discharge themselves,but at least you cen recharge them to a full capacity.For cameras - absolutely the highest capacitance you can get.Don''t fall for names and pre-charged.Just look at the capacitance , like Meredith did.
Thank you Margery - I hope that you have spring already. :o)

at 3/24/2009 1:26:29 PM, Mohamed Shaltot said:
I've tried about 6 or 7 brands in the past 8 years (NiMH chemistry). For photographic needs in particular, where you need to rely on batteries which hold their charge even if left unused (in a charged state) for a few weeks, nothing beats the ultra-low self discharge of NiMH batteries such as Sanyo Eneloop or Sony CycleEnergy. Ultra-low self discharge batteries typically have lower capacities (2000mAh vs 2600 or 2700), but they hold to their charge much longer (months instead of weeks), and they have lower internal impedance, which means they can deliver more current and cycle flash faster.

Here is a great study on self-discharge and regular discharge curves for various batteries. Try visiting
candlepowerforums.com/vb/showthread.php?t=149804

at 3/24/2009 1:33:35 PM, chbarg said:
I really like Sanyo Eneloops. I also have a lot of Energizer 2500 mAh batteries.
The main advantage of the Eneloop ones is that they retain they charge. I keep a couple sets in my camera bag as backups for my Nikon flashes.

at 3/24/2009 1:36:12 PM, PasadenaDave said:
One of the other magazines had a fairly long list of batteries, both rechargeable and single use, and the number of photos each would take in a serious study. The best overall single use was the lithium, but also the most expensive! DuraCell was slightly ahead of Energizer, but only slightly, and since Energizer tends to be much less expensive than DuraCell, a better deal. PS, there is a story out that many of the DuraCells are made at the same plant as Costco''s Kirkland batteries, so one may want to try some of those.

at 3/24/2009 1:38:47 PM, Chris PE said:
Actually not a full truth about pre-charged. Like I said they self-discharge , but pre-charged do the same and just logically they do NOT have a higher discharge current.Trust me - one of my professional flashes takes 8A at startup and precharged just give me 10 pictures.Regular Duracell -2650mAh almost 60.Try to experiment a bit more.Prechardged sometimes have a lower impedance and act like heaters ,when charged, then often they have O impedance ,or just open up.Like I said 3 out of 8 - BAD YIELD. I have used regular ones and never had a bad one yet.One thing is for sure - they are NOT (except Sony) sold with appropriate chargers.I am writing from practice, not theory. Every battery will cycle fast with Point And Shoot cameras.I am talking serious photographer here.Except Eneloops(overprices) I have not seen pre-charged that are higher than 2000 mAh capacities.Just my opinion.By the way - I constantly use about 50 Duracels.

at 3/24/2009 6:51:54 PM, Mohamed Shaltot said:
Low self discharge NiMH batteries use a slightly modified chemistry, which produces lower self discharge and lower internal impedance, which means it can deliver higher currents with less voltage sag, but at the expense of absolute capacity relative to a fully charged regular NiMH. Here is a link:

en.wikipedia.org/wiki/Low_self-discharge_NiMH_battery

This link tests MANY rechargeable batteries, including Sanyo Eneloop and your favorite (Duracell 2650, scroll 2/3 of the way down). As you can clearly see, Eneloop beats Duracell (and almost all rechargeables) in terms of current delivering ability (i.e. lower internal impedance). See it testing all the way to 10Amps (the Duracell 2650 maxes out at 7 Amps):

candlepowerforums.com/vb/showthread.php?t=79302

Regarding low self discharge, I am not sure if you had a chance to check the link I previously posted, which shows results of tests done for 6 months and 1 year duration. These clearly show the superiority of low self discharge NiMH (at least Sanyo Eneloop):

candlepowerforums.com/vb/showthread.php?t=149804

I’ve tried regular high capacity rechargeable Sanyo, Sony, Duracell, Energizer, and other obscure brands such as NoMem. While Sanyo Eneloop and Sony CycleEnergy (which I am told is a rebranding of the Sanyo) have less capacity, the Eneloop and CycleEnergy have VERY CONSISTENT battery to battery capacity. This will really help in the situations where you are using more than one battery in series, and you are trying to avoid reverse-charging the battery with the least charge (which could happen if the batteries in your ‘pack’ are not ‘matched’, as done by R/C enthusiasts to maximize the life of their packs. Reverse charging would drastically reduce the capacity of a battery and its life since it leads to ‘out-gassing’ and loss of chemicals. Within a few weeks of charging a regular NiMH and a low self discharge, the low self discharge will give you more mAh anyway!

To test and charge my batteries I used to use a homemade A/D converter connected to a computer to monitor the charge/discharge profiles (I am an electrical engineer), then I changed to a LA CROSSE BC-900 Battery Charger. Even at higher charge currents (>500mA) the Sanyo Eneloops develop less heat than the other NiMH varieties, which is testament to their lower internal impedance (until it gets to the end of cycle where you get the usual rise in temp associated with charge termination). Testing over the last 2 years showed me that Sanyo Eneloop and Sony CycleEnergy have the closest measured to advertized capacity than ANY OTHER rechargeable NiMH I have come across. I have about 20 Sanyo Eneloop, 8 Sony CycleEnergy, and maybe 40 others of different makes, mainly high capacity Duracell, Sanyo, and Energizer.

I am also a photographer, and in my Olympus FL-36 external flash, I can cycle from full power in about 6 seconds with the Eneloop, but it takes about 7-8 seconds with anything else (and more than 10 seconds with fresh alkaline). This is testament to the lower internal impedance.

As to your unfortunate experience with some low self discharge batteries, I would say it was a bad sample. The preponderance of scientific evidence out there certainly favors low self discharge batteries for photography (for having the batteries charged when needed even after extended storage, and fast cycle time), for stand-by applications (remotes, …low current drain applications), and for critical applications where you need every battery in the pack to give you its last bit of juice – R/C remotes and small cars).

If you are a photographer, do a search on a respectable photography site such as: www.dpreview.com/ and you will find nothing but praise for Eneloops. Here is another photography thread which talks specifically about using them in flashes. Again, nothing but praise for Eneloop:

photography-on-the.net/forum/showthread.php?t=444060

As for low self discharge being overpriced, well, I can get them from the internet for $11.99 for 4 AA, which is probably $1-$2 more than others, but I think the peace of mind is certainly worth the price.

at 3/25/2009 11:08:06 AM, Meredith Poor said:
Off topic link on a method of improving solar cell conversion efficiency.

www.eurekalert.org/pub_releases/2009-03/giot-slt032309.php

at 3/25/2009 2:43:32 PM, Chris PE said:
Under nom circumstances will I turn this blog into a "I know better"discussion. I have been an electrical engineer for the last 25 years of my life and have been a photographer for longer than that.EVERY photographer wants MAXIMUM pictures out of battery.Do you think that I want to replace batteries during an Air Show.....there goes 50-60 pictures.Duracell NiMH 2650 made in Japan is the best for every photographer.No doubt about it.I have checked it.I did buy some pre-charged and their capacity is NOT enough for a busy photographer.I am not talking about shooting family pictures , but going hiking and taking 2000 pictures. I loved one comment about us(engineers) actually liking to use our chargers.I do :o) This is all just my opinion.Interesting discussion.

at 3/25/2009 9:41:27 PM, Mohamed Shaltot said:
Chris, with all due respect, I think you might''ve missed the point of my whole discussion! If you want high capacity, and you will use the batteries soon after recahrging them, then by all means go with your favorites - Duracell 2650 (I would do the same). If, on the other hand, you want high current drain (up to 10 Amps) or low self discharge (so that the batteries are ready a few months after you last charged them), then all the studies I quoted point to ultra low self discharge NiMH. So it all Depends on your dapplication. Simple.

at 3/26/2009 11:35:05 AM, Chris PE said:
Thanks Mohamed.I absolutely agree with storage subject.

Thank you Margery for allowing us have an interesting discussion. :o)I just love your articles! They make people think!

at 4/2/2009 8:32:12 AM, Meredith Poor said:
Another off topic link involving generation of methane directly from electricity: www.eurekalert.org/pub_releases/2009-03/ps-mte033009.php. ~~~ At 80% conversion efficiency, the resulting fuel would cost the equivalent of 72 cents per gallon (although it is a gas, not liqid). With the usual pump taxes the resulting price would be about $1.14 per 'gallon'. Question is, how close to real is this thing?

at 4/15/2009 10:14:37 PM, greenpower said:
This battery reach the satandard?

SONY Cybershot DSC-T20 Battery is one of the long-term use replacement battery for digital camera in our on-line battery store, like most batteries for Sony Cyber-shot cameras in mid-range and Sony a series DSLR in high-end, our SONY Cybershot DSC-T20 camera battery have a good compatibility and long-lasting performance. For the after service, Cybershot DSC-T20 SONY battery enjoy a 12 months and 30 days money back guarantee!

www.canon-digital-camera-battery.co.uk/batteries/sony-cybershot-dsc-t20.htm

at 4/21/2009 12:16:47 PM, Phansigar said:
Meredith P: "...how close to real is this thing?" Do you mean is the lab result genuine? Absolutely. Or do you mean how close to an actual application? If so, not at all. At the moment it''s a lab finding. Nobody has tried to turn it into an actual fuel producer.

Possible problems: First, can it be engineered into an industrial process? Second, if so, will it scale to produce commercially usable fuel? Third, If so, will the process (conversion efficiency) be high enough to be affordable? Fourth, if so, and after all this, will the end product (methane) be commercially affordable?

In addition, the Archaea may be self-reproducing, but will they last long enough in commercial processes or will they need constant replenishment (=added cost)?
Will there be enough non-carbon based electricity available at a reasonable cost to make commercial production viable, or will it be diverted from other uses, equaling an essentially zero-sum situation?

And none of that addresses whether or not car manufacturers, for example, will make the engines that run on methane.

The above doesn''t mean it won''t turn out to be a good commercial source of methane, but those are the sorts of considerations that go into turning a lab result into a real product. Let''s hope it turns out to be usable and affordable.

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