Request for AA Battery Donation - Scientific Experiment - Page 1
Forum section: electronics / general

author: tom66
author_rank: Super Contributor
timestamp: December 13, 2012, 11:43:37 pm
content: Hi all,I put togetherhttp://www.batteryshowdown.com/(including the analyser itself) over last summer as part of my internship at a local engineering firm, BitBox Ltd.The results were very surpising -- it appears cheap alkalines perform far better than their price would suggest! And, it was hugely successful, with over 70,000 hits. Now, I'm back for more!We have had lots of requests to test various different batteries. Ray-O-Vac is the most common request from most American readers; I can't buy them in the UK, so if anyone can source them, that would be appreciated. But if you see any battery that we have not tested (and it's not in the to-be-tested list below), let me know by sending a message. We need batteries in retail packaging with a receipt for pricing information; we'll need at least two and four are good so we can do repeats or in case one test gets messed up. Feel free to nick a few batteries from the pack for your own purposes, but please do not send in used or old battery packs as it will affect the results. We're only testing AA cells for now, as we expect the results to be roughly similar over the whole range.For now, we're testing alkaline, lithium, ni-oxy hydroxide and zinc chloride cells. We will test rechargeables another time -- the analyser requires a re-design for that.I am in the process of adding (testing):* Ikea "Alkalisk" (cheap 10p/ea)* ReadyCell (cheapest alkaline at 9.9p/ea)* PowerCell Ultra Alkaline* Maplin extralonglife Alkaline* Sony "New Ultra" Zinc* Kodak Zinc* Sainsbury's long life* Morrisons Saver Zinc* JCB ZincIf anyone would like to donate batteries please let me know via PM. They need to be posted to the UK, and wemaybe able to contribute the cost back for some donations. You can have your name put on an acknowledgements page if you like.To be released as well, full schematics, PCB layout and software for the analyser. Hopefully by tomorrow.

author: Spikee
author_rank: Frequent Contributor
timestamp: December 14, 2012, 12:06:07 am
content: You should put a disclamer at the bottom of the website to make sure some stupid company wont sue you because of slander( google translate) . But it's a good initiative . Just an idea but somebody should make a kit for a low power dummy load that logs the stuff in eeprom and transfers it via serial to the pc who will publish it on a central website. Than you can test alot of battery's from different countries using the same platform.... just an idea :p

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 12:11:36 am
content: Quote from: Spikee on December 14, 2012, 12:06:07 amSchematic, PCB and software will be released; anyone can make one for less than £20.BitBox are not in the business of making small kits, the margins are way too thin. Others are welcome to, though.Disclaimer wise, this is what we have, on the front page: "We are presenting a factual survey of batteries. The selection of batteries is not exhaustive and we have not deliberately included or excluded any brands or manufacturers. We are not recommending any manufacturer or brand based on these results and leave this up to the reader to decide which batteries to buy."

author: olsenn
author_rank: Frequent Contributor
timestamp: December 14, 2012, 12:14:00 am
content: Kirkland (Costco brand) AA batteries: I tested under drains of 0.1A, 0.5A, 1A, and 2A. Here are the results:

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 12:15:52 am
content: We tested Costco Kirkland Signature and found them to be one of the best alkalines, and they're really, really cheap at about 21p each.We got a capacity of 1176mAh at 1 amp.

author: Spikee
author_rank: Frequent Contributor
timestamp: December 14, 2012, 12:59:40 am
content: put in something like:These were our personal findings out of a small test batch.this may not represent the actual figures or something like that.You "claim" that "We are presenting a factual survey of batteries"They may wine :Meters last calibratedhumidityroom temperaturecell temperatureaccuracyonly small batches testedi'm not good enough at english to put all that stuff in a simple sentence but you probably can.I don't know how to program cortex micro's so that may be a problem for me and other hobbyist .

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 11:02:13 am
content: We have:Custom boards calibrated to +/-2% using a set of transferable standards (Thulby Thandar 1604 & Fluke 179.)RH <90% guaranteedRoom temperature 20C - 25CCell temperature -- depends on load current and room temperaturePlus, we only provided factual information, like any review would. This is protected speech.I dare them to try to sue us.

author: sorin
author_rank: Frequent Contributor
timestamp: December 14, 2012, 07:22:16 pm
content: I think that the ESR should be measured too.

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 07:32:28 pm
content: Quote from: sorin on December 14, 2012, 07:22:16 pmThe design accommodates this, but there's too much variation between each analyser (connector, calibration, etc.) that we haven't included it.V2, if made, will add ESR testing using an applied ac waveform with variable frequency.

author: mariush
author_rank: Super Contributor
timestamp: December 14, 2012, 08:41:43 pm
content: Can you please make a list somewhere with what you already have so I won't buy the same stuff?I'm hoping to get some Toshiba, Sunlight, maybe Panasonic and Energizer and some hypermarket branded stuff (Carrefour, Auchan etc) batteries among others and overall, they're not exactly cheap here, with the 24% vat.

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 08:43:00 pm
content: Quote from: mariush on December 14, 2012, 08:41:43 pmThe list is here:http://www.batteryshowdown.com/results-hi.htmlalong with the following others which will be added shortly:* Ikea "Alkalisk" (cheap 10p/ea) [on test tonight]* ReadyCell (cheapest alkaline at 9.9p/ea) * PowerCell Ultra Alkaline * Maplin extralonglife Alkaline [on test tonight]* Sony "New Ultra" Zinc [on test tonight]* Kodak Zinc [on test tonight]* Sainsbury's long life * Morrisons Saver Zinc [on test tonight]* JCB Zinc [will test soon]We've done a lot of Panasonic and Energizers (see the list), but Toshiba/Sunlight/misc supermarket would be very interesting...

author: qno
author_rank: Frequent Contributor
timestamp: December 14, 2012, 08:55:00 pm
content: hi, You can claim that its s compare test. The batteries ar all tested with the same tester. So far you are safe.

author: tom66
author_rank: Super Contributor
timestamp: December 14, 2012, 08:57:26 pm
content: I am claiming it is not only a comparison test but a real test with an accurate discharge load that we built at BitBox.I do not know why everyone is so worried about this. The site has been up for ~3mo and had 70,000 hits, yet no one has sued us.Because any reasonable court would throw it out.And (most of) the source is now up...http://www.batteryshowdown.com/source.htmlUnfortunately, can't yet release the STM32 code (hope to do that soon; but some of the code we used belongs to customers.)