Which battery is better? The result... it may surprise you!

[tom66]

I have just finished the first run of a project at work to find the best value battery, the most mAh/mWh per penny. For now, I'm only considering AA alkaline and zinc chloride cells.

The result was very surprising. Test at 200mA +/- 3mA for approx 12 hours using custom built constant current load, terminating at 0.8V. All cells were purchased new from Tesco.

Results

1st. Duracell Plus Power  - 2355mAh - 2887 mWh - 11:52:46 - 34.5p/Ah
[B]2nd. Tesco Extra Long Life - 2299mAh - 2853 mWh - 11:34:08 - 13.0p/Ah[/B]
3rd. Energizer ULTRA+   - 2293mAh - 2832 mWh - 11:18:29 - 35.4p/Ah
4th. Energizer HIGHTECH  - 2263mAh - 2801 mWh - 11:26:01 - 41.1p/Ah

Surprisingly, the Tesco battery did very well! And, it only costs 13p/Ah. Its ESR was also very low - approx 110mOhm, which was nearly identical to the others. Also, the HIGHTECH battery is more expensive per Ah (costs £3.75 for a pack, vs £3.25) and is supposed to last "45% longer" in digital cameras, but it comes out nearly the same in the results! The ESR was marginally lower, but it could be manufacturing variation. Looking closer at the pack, it compares it to "Energizer Classic", not "Energizer Ultra+", the battery that is recommended. I cannot find these batteries for sale anywhere in the UK -- so I have no idea if this is just a battery made up for the purposes of marketing!

Next for comparison - "Ni Oxy Hydroxide" and Lithium type AA cells, as well as possibly rechargeables - and others. Results will be published.

[Rulycat]

Re: Which battery is better? The result... it may surprise you!

Great. Looking forward to see the rechargeable results. Will have to keep this in mind when I shop! Where are the Tesco batteries made? China I presume? The Energizers usually seem to be U.S.A made and the Duracells Belguim or just "EU".

[tom66]

Re: Which battery is better? The result... it may surprise you!

Great. Looking forward to see the rechargeable results. Will have to keep this in mind when I shop! Where are the Tesco batteries made? China I presume? The Energizers usually seem to be U.S.A made and the Duracells Belguim or just "EU".

Yep, Tesco batteries are China made. I did test some M&S batteries on the first prototype (didn't do a detailed log though) - they came out as about the same as Tesco and they were made in EU. Energizers are both US made and Duracell I think is Belgium, can't remember though.

[kc8adu]

Re: Which battery is better? The result... it may surprise you!

i use sanyo eneloops almost exclusively now.
too many items wrecked by crappy duracells and energizers.
one of my custom modded flashlights takes 1.5a to run.alkalines suck for that.
interestingly enough many store brands are custom labeled major brands and perform the same since the label is the only difference.example is the sams club members mark aaa.
identical to energizer except the label.we stock them for the cheap and nasty 3aaa chinese flashlights in the toolkits.they are sacrificial.the helper kids dont touch my modded arc-ls or my business partners either.if they leak we just toss and wait for a free harbor fright coupon.

[retiredcaps]

Re: Which battery is better? The result... it may surprise you!

Next for comparison - "Ni Oxy Hydroxide" and Lithium type AA cells, as well as possibly rechargeables - and others. Results will be published.

As a kid, I remember going to Radio Shack and joining their "get a free" monthly battery club. I would get this business card with 12 "punches". I would look through their catalog for hours particularly in the battery section and then tried to get what I wanted.

So I have huge interest and fond memories in your findings.

For a while, I hung out at candlepowerforums researching nimh batteries. I wonder if members there would be interested in your findings?

Today, I try to use/buy eneloops when they are on sale for about $2/cell.

[retiredcaps]

Re: Which battery is better? The result... it may surprise you!

i use sanyo eneloops almost exclusively now.

How are the 4 for $1 Big Lots nimh's doing?

[budm]

Re: Which battery is better? The result... it may surprise you!

Consumer report magazine does this testing every year around Christmas time since a lot of people will be buying batteries for their children's toys.
http://www.consumerreports.org/cro/batteries.htm

[tom66]

Re: Which battery is better? The result... it may surprise you!

Does anyone know what Consumer Report's conclusion was? So far my conclusion is every battery is pretty much alike. I'm repeating the test and will find out on Monday, I'm also comparing crappy zinc-chloride cells (one did 660mAh before dying...)

[tom66]

Re: Which battery is better? The result... it may surprise you!

If anyone in the UK is willing to send batteries, NEW (<3 months old) in retail package (even if some have been removed, but the ones in the packet must be unused), please send me a PM. I may be able to pay the cost of postage. I need at least two batteries to do a test as I plan to test low and high discharge.

Any that I can test will be published on my employer's website for everyone to view.

We are also logging the voltage discharge curve, I have noticed that some of the cheaper batteries tend to give a lot more energy at lower voltages, but the Tesco own brand did fairly well, about as well as the Energizers and better than the rest at the start.

[tonyncchan]

Re: Which battery is better? The result... it may surprise you!

Any one know if we can tell the remained capacity by looking at the battery voltage?

[mariushm]

Re: Which battery is better? The result... it may surprise you!

No, you can't really tell.

Non-rechargeable batteries are about 1.55-1.6v when fully charge, go down to about 1.45-1.5v at 80-90% then slowly go down to about 1.35v when they're dead. The voltage difference is too little to reliably tell how much is left in them.

Rechargeable ones are even harder - 1.2v batteries fully charged are about 1.3-1.4v, they go steadily down towards 1.1v-1.15v and at a point they just drop instantly.

See the graphs here, just imagine there's 4 rechargeable batteries: http://shdesigns.org/batts/battcyc.html

[tom66]

Re: Which battery is better? The result... it may surprise you!

No, you can't really tell.

Non-rechargeable batteries are about 1.55-1.6v when fully charge, go down to about 1.45-1.5v at 80-90% then slowly go down to about 1.35v when they're dead. The voltage difference is too little to reliably tell how much is left in them.

Rechargeable ones are even harder - 1.2v batteries fully charged are about 1.3-1.4v, they go steadily down towards 1.1v-1.15v and at a point they just drop instantly.

See the graphs here, just imagine there's 4 rechargeable batteries: http://shdesigns.org/batts/battcyc.html

In my tests at a constant current (not constant resistance or power, but I will experiment wih both) alkaline cells will decrease steadily until about 0.9V and then begin a rapid drop to 0.8V within about 10 minutes; from then on, about 20-30 seconds later they reach 0.4V. The load will stop accumulating mAh at 0.8V, but will continue the distance until 0.4V (at which point it stops because the load current cannot be guaranteed - the gate drive to the FETs saturates.)

[mariushm]

Re: Which battery is better? The result... it may surprise you!

Yes, you're right. 0.8-0.9v sounds more reasonable for alkaline cells.

I was writing the previous post from memory and I probably mixed it up with Ni-Cd or other chemistry batteries.

[tom66]

Re: Which battery is better? The result... it may surprise you!

I have been down to the local pound stores and 99p shops and picked up four packs of alkaline batteries.

Daewoo Super Alkaline  - £0.99 for 6 - 16.50p each - Made in ???? 
Kodak Xtralife      - £1.00 for 6 - 16.67p each - Made in China
Panasonic Alkaline Power - £0.99 for 4 - 24.75p each - Made in Belgium
Sony Alkaline      - £1.00 for 4 - 25.00p each - Made in Indonesia

So I will put these on discharge tomorrow and see how they compare as they are about the cheapest alkalines you can get.

[mariushm]

Re: Which battery is better? The result... it may surprise you!

See if you can get these (cheap but they probably screw you at shipping):

http://www.amazon.co.uk/Draper-Heavy...515042&sr=1-10
http://www.amazon.co.uk/Panasonic-R6...515093&sr=1-27
http://www.amazon.co.uk/Draper-Heavy...515093&sr=1-47
http://www.amazon.co.uk/Verbatim-499...515157&sr=1-49
http://www.amazon.co.uk/Sony-Ultra-H...515093&sr=1-30
http://www.amazon.co.uk/Panasonic-R0...515157&sr=1-68


Amazon Basics would be nice to review but they're usually sold in packs of 20 or something like that

PS. There's a "smart" battery charger sold under various brands that has "discharge" and mAh measurements features for rechargeable batteries:

http://www.amazon.co.uk/s/ref=nb_sb_...bc-700&x=0&y=0

Check it out. I am planning to buy one but just couldn't find anything else to buy from Amazon.co.uk so that the shipping charges won't be so big. Shipping one to me would be 4-5 pounds... yet it costs about the same to ship if I add 3-4 Kg of other crap to the
package.

[tom66]

Re: Which battery is better? The result... it may surprise you!

Most are heavy duty (zinc chloride) and plus £4-£5 shipping. I know zinc chloride will not last because the chemistry is only really suitable for things like remote controls and wall clocks.

[kc8adu]

Re: Which battery is better? The result... it may surprise you!

i use the maha.powerex c9000.
i have done discharge tests on alks.get a 4 pack and do 100,200,500,and 1000 ma.

[kc8adu]

Re: Which battery is better? The result... it may surprise you!

they seem to be doing fine.the only ones i have left are in 2 cnb-152 packs for my standard c228a ht.they have about 20 cycles on them using the fast charger.

How are the 4 for $1 Big Lots nimh's doing?

[tom66]

Re: Which battery is better? The result... it may surprise you!

The Showdown site is officially UP...

http://www.batteryshowdown.com/

The results were revised due to a testing error (we were drawing too much power from the laptop's USB port, which was causing brown-outs and strange voltage dips), so please ignore the above results and look at the new ones, as they are now accurate (using a powered hub.)