Ni-MH manufacturer reliability and mAh claims - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: December 31, 2011, 02:21:23 pm
content: well I bought a new compact digital camera and it takes AA batteries. So I need to get some rechargeable's for it. Now eBay has plenty of no name brand stuff that ships form china and now claiming 3000 mAh capacities versus all of the out of date stuff UK sellers are trying to flog off like ancient 1700 mA batteries and a few of the more recent 2100 mA batteries.My policy is that the bigger the battery the more recent it was made and the more life in it, getting 1700 batteries on offer is pretty point less as they are going to be 2/3 the way through their shelf life already leaving me with about a years use.

author: Zero999
author_rank: Super Contributor
timestamp: December 31, 2011, 02:38:15 pm
content: How often do you plan to use the camera after the batteries have been charged?Capacity isn't everything, when it's not going to be used very often, leakage and charge retention are often more important. I have some lots of 2.5Ah and 2.7Ah batteries for my camera but they don't hold their charge for very long. Next time I go away on holiday I think I'll take some newer batteries with better charge retention characteristics even if their capacity is lower.I say, buy from a proper branded batteries from a known distributor such as RS, Farnell, Rapid etc. rather than some random ebay seller.

author: Fraser
author_rank: Super Contributor
timestamp: December 31, 2011, 02:39:24 pm
content: Simon,I advise caution here.You never get anything for nothing :-)From my experience, any Ni-Mh AA cell rated over 2100mAH is a compromise. The greater capacities come at the cost of shorter life due to accelerated capacity depletion (ageing). The very large mAH capacity batteries from well known manufacturers have been known to have significantly decreased capacity after only a relatively short number of charge/ discharge cycles so the benefit of their greater original capacity is soon lost.I personally use 2100mAh and 2500mAh batteries from Uniross and these seem to be holding up well under light use, but digital cameras really test a cells 'metal' !With regard to 'cheap' or even expensive Chinese / unknown brand batteries on ebay....be VERY careful ..... I have a piece of test equipment called the Optim Engineering CBAIII that tests the true capacity of batteries using an electronic load. I recently purchased several AA battery packs from various ebay sources. They all had light green sleeving with 'dot matrix' style inkjet markings on them. The CBAIII showed them all to be fraudulent in their capacity claims. A battery rated at 2600mAh actually provided only 650mAh of capacity....now that is royally taking the mick in my opinion !No name batteries carry a risk of over hyped capacity claims for a cell that is actually a much lower capacity.I can recomemend the CBAIII to anyone seriously interested in battery quality testing :-)It isn't cheap but it works well. (I managed to get an 'as new' one for GBP60 on ebay last year)Links here:http://www.westmountainradio.com/product_info.php?products_id=cba3&navcode=/cbaLink1http://www.optimengineering.com/content.php?page=supportcbahttp://www.batteryjunction.com/western-cba2.htmlMaybe Dave could consider resurecting HIS battery testing project that was briefly referrred to in one of his Videos.

author: Richard W.
author_rank: Regular Contributor
timestamp: December 31, 2011, 02:50:23 pm
content: @Simon: What about eneloop-batteries? (or any other low-self-discharge-type)3000mAh are useless, if 1500mAh are gone after a few weeks because of the insane self discharge of regular NiMH batteries.

author: Lightages
author_rank: Unknown
timestamp: December 31, 2011, 03:10:14 pm
content: RichardIt is not a question if one should buy Eneloops, it is a no brainer. As you said with regular nimh cells, they are useless without constant care and feeding. I absolutely hated picking up any device only to find that the batteries were dead from sitting for 2 weeks. Eneloops might cost a bit more but without a doubt in my mind they are worth the price. There are other manufacurers of low self discharge types too.

author: Simon
author_rank: Unknown
timestamp: December 31, 2011, 03:41:19 pm
content: yes well under £4 for 8 x 3000 mA cells did sound a bit too good to be true, I'll look up some branded batteries in the 2100-2500mA range

author: grenert
author_rank: Frequent Contributor
timestamp: December 31, 2011, 03:43:06 pm
content: I completely agree that Eneloops are the way to go. They have a minimum of 2000 mAh for AA, and the latest models have more than that (but I think are more expensive). They are so stable after charging that you can even use them in seldom-used devices, and they will still work when you take out the device after many months. I have had plenty of problems with no-name and higher capacity batteries which self-discharge so quickly as to be useless for most purposes. In general, the older, lower capacity batteries (1400-2000 mAh) I've had have shown less self-discharge. However, those have capacities in the Eneloop range, so you might as well get the Eneloops.I haven't ever noticed that NiMH batteries degrade sitting on the shelf.

author: samgab
author_rank: Frequent Contributor
timestamp: December 31, 2011, 04:36:41 pm
content: Quote from: Simon on December 31, 2011, 03:41:19 pmOne word: eneloops.More words: You won't regret it. They're the best NiMH cells I've come across. They only have 2000mAh, but their mAh claims are genuine (unlike those "3000 mAh" wun-hung-lo cells), the cells are extremely consistant. They're also very reliable, capable of sustaining high current draws, and looked after last years and years. Well worth the money and then some. Also good to have a good independent channel charger, such as the Maha MH-C9000.

author: IanB
author_rank: Super Contributor
timestamp: December 31, 2011, 05:08:00 pm
content: The world is full of crap NiMH batteries and many of them are found on eBay.As others have said, if you want good batteries get eneloops. Make sure you buy from a reputable dealer (e.g. 7DayShop, Amazon) as counterfeit eneloops have shown up in some of the "cheap and cheerful" sales channels.There are many ways to judge the quality of NiMH batteries including cycle life (how many times can you charge and discharge them without losing capacity and performance), maintenance of charge when not in use (low self-discharge), internal resistance and performance under load, tolerance of less than ideal charging, robustness and maintaining good performance after being used for a while, and so on. Eneloops are arguably best in class at all of these.It is not a good idea to focus on capacity to the exclusion of other things. Firstly there is no such thing as a 3000 mAh AA NiMH cell. Such claims are exaggerated. 2700 mAh is about the limit, and even the genuine 2700 mAh cells typically measure somewhere in the 2500-2700 range. But the problem with 2700 mAh cells is that so many compromises have to be made to squeeze that much capacity into the cell that you get a fragile design that will not maintain its "as new" level of performance for very long. Unless you have a very good reason to need the extra capacity 2700 mAh cells are best avoided. Good robust cells tend to be in the 2000-2200 mAh range.

author: ModemHead
author_rank: Frequent Contributor
timestamp: December 31, 2011, 05:12:04 pm
content: Another vote for Eneloops.

author: ipman
author_rank: Regular Contributor
timestamp: December 31, 2011, 05:31:38 pm
content: Eneloops are marked "minimum 1900mAh".I have 32 of them, in use in different devices and roles, and none dissapointed. All other non-LSD batteries died in the mean time, and I did not replace them, it's not worth it.LSD rechargables, cheap, but good enough are ReCyko from GoldenPeak-GP, a chinese manufacturer. Another good ones rated for 2200mAh came from England-based Turnigy,link here, a well-known brand in model world, which, altough provenience is unknown, they are good enough and they don't lie about capacity.

author: RCMR
author_rank: Frequent Contributor
timestamp: December 31, 2011, 10:25:37 pm
content: Eneloops seem to have solved the high self-discharge rates intrinsic to most hi-capacity (>1600maH) AA -sized NiMH cells but beware, there are a growing number of knock-off Eneloop counterfeits coming out of China and they're just relabeled crap.If you can't get genuine Eneloops, get a good set of Panasonic or Sanyo 1600mAH cells - they have low self-discharge and although the capacity is (in theory) lower than those 2200-3000mAH cells you see advertised, they actually deliver more useful shots in most cameras because they have a very low internal resistance so less of their energy is wasted in simply heating the battery when used with reasonable loads.The real answer is to go to a single LiFePO4 cell -- it's 3.3V, has a lower self-discharge than even the best NiMH and has a lower internal resistance as well. Unfortunately, the form-factor would be an issue. I'm actually surprised that nobody's making LiFePO4 cells in 2xAA form-factors because they'd be a brilliant retrofit for so many devices.

author: IanB
author_rank: Super Contributor
timestamp: December 31, 2011, 11:27:42 pm
content: Quote from: RCMR on December 31, 2011, 10:25:37 pmThe "lower internal resistance" of an LiFePO4 cell is an undue generalization. In their normal, unmodified form LiFePO4 cells have quite a high internal resistance. This is one of the limitations that has inhibited their wider adoption. For instance, I have a nice quality 14500 (AA) size LiFePO4 cell that I was hoping to use as a substitute for 2xAA NiMH, but its internal resistance is in the order of 350 milliohms. If you try to make it deliver 1 A or more the voltage sag is quite severe. In contrast, good quality NiMH cells like eneloops can go up to 5 A or so.Granted, some LiFePO4 cells like the A123 or K2 Energy types can be constructed with low internal resistance, but this kind of construction is special and more expensive and limits the cell capacity.

author: ipman
author_rank: Regular Contributor
timestamp: January 01, 2012, 01:35:50 pm
content: Forgot to add: according to my personal analisys of my 32 Eneloops of 4 diferent generations, their capacity is generally between 1930 and 1980 mAh. According to a Maha MH-C9000 charger/analyser.Their biggest advantage is the very low internal resistance, which can be measured with an ESR-meter if they are in series with a capacitor.

author: Richard W.
author_rank: Regular Contributor
timestamp: January 01, 2012, 03:27:17 pm
content: Quote from: RCMRI also thought about LiFePO4 cells for my battery-eating flashlight (fenix tk41).The 8 batteries could maybe replaced by 4 14500-LiFePO4-cells and 4 battery dummys.But the energy density of LiFePO4 is not twice as big as the energy density of NiMH. So this wouldn't make sense.http://en.wikipedia.org/wiki/Rechargeable_battery#Table_of_rechargeable_battery_types

author: Slobodan
author_rank: Regular Contributor
timestamp: January 01, 2012, 05:55:00 pm
content: @SimonThis should help:The Best Rechargeable Batteries and Chargers Of 2011

author: IanB
author_rank: Super Contributor
timestamp: January 01, 2012, 07:01:15 pm
content: Quote from: Slobodan on January 01, 2012, 05:55:00 pmI'd ignore that article. The Eneloop recommendation is OK, but several other recommended products have been discontinued and were not even available in 2011. It is a badly researched piece of space-filling fluff.

author: Simon
author_rank: Unknown
timestamp: January 01, 2012, 07:50:23 pm
content: well I have found eneloop's starting at £4.99 although even in pairs they start at about that. Sound about right price ?http://www.tekshop247.com/sanyo-eneloop-batteries-pack-p-154180.htmlhttp://www.bestofferbuy.com/Sanyo-Eneloop-PreCharged-Rechargeable-NiMH-AA-Batteries-2Pack-p-16410.html?currency=GBP&utm_source=gbase&utm_medium=cse&utm_campaign=gbase_ukhttp://www.heathfields.co.uk/sanyo-eneloop-aa-4-pack-batteries-2000mah?c=01&i=B000IDUOPA

author: Lightages
author_rank: Unknown
timestamp: January 01, 2012, 08:50:11 pm
content: That sounds like a normal price. They do go on sale in Canada on the Dell site here and right now you can get 8x AA, 4x AAA, and a charger for $30CDN.

author: Simon
author_rank: Unknown
timestamp: January 01, 2012, 08:56:33 pm
content: right, I'll have to look up a charger next, do sanyo do one for eneloops ?

author: Lightages
author_rank: Unknown
timestamp: January 01, 2012, 09:03:31 pm
content: Have a look at this page Simon. I know its not where you can buy but it shows you some of what is available and and at what price. NiMH batteries all use the same charger. If I were you I would get an Ansmann charger that does a better job of managing he charging.http://search.dell.com/results.aspx?s=gen&c=ca&l=en&cs=&k=eneloop&cat=all&x=0&y=0

author: Simon
author_rank: Unknown
timestamp: January 01, 2012, 09:04:50 pm
content: ok thanks, I'm not too particular about chargers but so far have only used basic ones that often put 2 cells in series and or are just constant current chargers with a timer.

author: samgab
author_rank: Frequent Contributor
timestamp: January 01, 2012, 09:06:01 pm
content: Quote from: Simon on January 01, 2012, 08:56:33 pmSanyo does a few different models, be careful which one you get. Sometimes they come packaged with 4 eneloops.But the "standard" charger (NCMQN04) I wouldn't recommend, because 1/ it's slow, and 2/ it doesn't have 4 independent channels. It combines the channels into pairs, which isn't ideal. It's better to treat each battery independently.Their "quick" charger (NCMQR06) is okay. It at least has 4 separate channels and is a bit quicker to charge, although at different rates depending if you are trying to charge 1, 2, or 4 cells at a time.But a better option would be one of the Maha smart chargers. Ideally, if you can afford it, the MH-C9000.That is a good one, because you can match your cells up by their real capacity and see how they are really performing, with reasonably accurate measurement of their capacity in mAh. The 4 bays are independent, and you can fine tune the charge and discharge rates in 100mA steps. It's also quite gentle on cells whilst also being fast, so win/win.You can get it for <$50, and it's well worth the spend.Best price in UK is at CPC:http://bit.ly/rspBcm

author: Lightages
author_rank: Unknown
timestamp: January 01, 2012, 09:06:30 pm
content: I have this one:http://www.ansmann.de/cms/consumroot/chargers-and-power-supplies/fast-chargers/energy-16.htmland it takes care of everything very well.

author: IanB
author_rank: Super Contributor
timestamp: January 01, 2012, 09:10:09 pm
content: Quote from: Simon on January 01, 2012, 09:04:50 pmDo be particular about chargers. The money spent on eneloops will be wasted if you destroy them with a crap charger.Look for a smart charger with individual charging channels on each cell, a charging current greater than 500 mA and automatic charge termination.Sometimes eneloops come bundled with a Sanyo charger. While some of those Sanyo chargers seem not to meet the criteria just given they do seem to be reliable and of course will not void the warranty on the eneloops, so are worth getting. Often you get a "free" charger for the price of four batteries.

author: Simon
author_rank: Unknown
timestamp: January 01, 2012, 09:12:56 pm
content: yes well getting eneloops I want a more decent charger and my dad needs a charger anyhow, I might get a kit

author: Simon
author_rank: Unknown
timestamp: January 01, 2012, 09:24:37 pm
content: well the MQR06 is min £19 with batteries (4 x AA), only one outlet has them at that price, the others go for £27+

author: samgab
author_rank: Frequent Contributor
timestamp: January 01, 2012, 09:37:09 pm
content: Quote from: Simon on January 01, 2012, 09:24:37 pmYou'd be far better off getting the MQR06 than the MQN04 or another model "overnight" or "standard" charger.The disadvantage of slow chargers with NiMH chemistry, is they can't generate enough temp increase or negative-­delta-V signal to terminate correctly, so they rely on a timer. The problem with that is a timer can't determine the State Of Charge when the cells were put on the charger, so they can overcharge, reducing the life of the cells.Also, a charger that charges in pairs can unbalance cells, which can result in reversing the cells when they are later in use in multi-cell devices. That, in turn, again reduces the life of cells.When you consider that eneloops are an investment that can last for many years if treated properly, it's worth spending a few extra dollars on the charger.

author: Rufus
author_rank: Super Contributor
timestamp: January 02, 2012, 08:58:18 am
content: Quote from: samgab on January 01, 2012, 09:06:01 pmThe BC-700 (BL-700) is a similar 4 cell smart analyzer/charger available from Amazon in the UK at about half the price.In passing I think something like this would make quite a nice open hardware (or whatever you want to call it) project. The electronics isn't too difficult and there is a lot of scope for firmware development and possibly connection to a PC for more detailed analysis and recording.

author: Simon
author_rank: Unknown
timestamp: January 02, 2012, 09:21:11 am
content: Quote from: Rufus on January 02, 2012, 08:58:18 amthey are quite pricey on UK amazon.

author: ipman
author_rank: Regular Contributor
timestamp: January 02, 2012, 09:50:01 am
content: Yes, MH-C9000 is now the top of the range from Maha, so it's expensive (between common chargers, of course). Be aware that chargers used in model world can go up to hundreds of euros, and of course are better: higher current, data logging, etc.Ansmann have a decent line of chargers, look for "quick" ones with 4 independent channels.I strongly recommend MH-C9000 or the LaCrosse BC7000 or BC1000, they are now the top chargers in the consumer market. A charger with overheating protection will be good if you charge a variety of cells from various manufacturers.Eneloops cells like a 1000mA charge current, and at that current they have the best voltage drop.

author: Slobodan
author_rank: Regular Contributor
timestamp: January 02, 2012, 09:54:32 am
content: Quote from: IanB on January 01, 2012, 07:01:15 pmhttp://www.e8ge.com/batteries/http://www.uniross.com/eu/product_info.php?products_id=404http://www.uniross.com/eu/product_info.php?products_id=403

author: IanB
author_rank: Super Contributor
timestamp: January 02, 2012, 11:14:45 am
content: Quote from: Slobodan on January 02, 2012, 09:54:32 amYou know, I didn't say all of them have been discontinued, I said several of them.But in the case of Hybrios, depending on when and in which region purchased, many different cells from different sources have been packaged with the Hybrio brand. Some have been excellent and some have been atrocious (I have examples of both). But fundamentally when you buy Hybrio batteries there is no way to know what you are getting. And without that assurance of provenance and quality it is impossible to recommend them.One reason for trusting eneloops is youknowwith certainty that every genuine eneloop is the same cell designed by Sanyo and manufactured at the eneloop factory in Japan. They are all guaranteed to perform the same way and there is no chance they got some other cell and put an eneloop label on it.

author: firewalker
author_rank: Super Contributor
timestamp: January 02, 2012, 11:29:10 am
content: I have bought the following product twice. For my Sony DSC-40 and for my father's digital sphygmomanometer.On my 1 week vacation i took almost 200 photos and the battery indicator was still foul. My father is using his sphygmomanometer daily for two months now without any low batt indication.http://www.ebay.co.uk/itm/110516788115?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649Alexander.

author: Lightages
author_rank: Unknown
timestamp: January 02, 2012, 11:54:07 am
content: Yes those Duracell NiMH batteries work very well too. The thing to watch though is that they are made in different countries. If they have anything other than a white insulator/separator on the positive end, then they are made in China. The Japan made ones have the white end.

author: firewalker
author_rank: Super Contributor
timestamp: January 02, 2012, 12:46:59 pm
content: Quote from: Lightages on January 02, 2012, 11:54:07 amIt is labeled as Made in Japan (with a gray insulator). I believe it is a genuine Duracell cell. The white insulator indicates an Enelope re-wrapped by Duracell battery.Alexander.

author: Lightages
author_rank: Unknown
timestamp: January 02, 2012, 02:59:55 pm
content: You are probably correct. The information I was going on is about 2 years old.

author: Polossatik
author_rank: Frequent Contributor
timestamp: January 06, 2012, 09:15:48 pm
content: Quote from: Rufus on January 02, 2012, 08:58:18 amanother vote for this charger , i use it together with eneloops (and some other brands) and it has not failed mea friend of mine has 4 of those chargers (professional photographer) for a year now and he's also very happy about them also.

author: G7PSK
author_rank: Super Contributor
timestamp: January 06, 2012, 09:38:53 pm
content: I have found a good way of judging batteries is by weight the heavier the better. Now before you all fall of your stools laughing, energy is heavy (E=MC2) but also the materials to store energy have mass and the more energy you want to store the more mass required for any given cell type, I am not comparing lead acid to lithium here but any cell of a given type, just weigh a Duracell battery and a cheap alkaline cell you will find the Duracell is much heavier, this appears to be the case with NiMi NiCad and all others the better the battery the more it weighs.

author: Simon
author_rank: Unknown
timestamp: January 06, 2012, 09:55:07 pm
content: Quote from: G7PSK on January 06, 2012, 09:38:53 pmyes I have always suspected this myself

author: IanB
author_rank: Super Contributor
timestamp: January 06, 2012, 10:00:45 pm
content: With NiMH cells the weight is certainly not a coincidence. It takes a certain amount of "stuff" inside the cell to store the electricity, and broadly speaking higher capacity cells should be heavier. For instance an AA size eneloop weighs about 26 g and this is typical of other cells with a 2000 mAh capacity also. If you get a cell with a 2000 mAh claim on the label and it only weighs 15 g you will know immediately it is fake without needing to test it.

author: sdttn
author_rank: Contributor
timestamp: January 07, 2012, 06:22:59 pm
content: I am using "sony cycle energy" in my fujifilm S5800. They are really good for price. I paid 15-20$ (I am not sure the price) for four batteries with charger. They are 2100mAh. Sometimes I forgot when I charged. They allways ready to use no self discharging.Edit: Photo.

author: saturation
author_rank: Super Contributor
timestamp: January 08, 2012, 01:38:04 pm
content: Key today with NiMH chemistry is insure whatever you buy is:Low self discharge type, like eneloop. Note, in late 2011 eneloop developed a newer chemistry than reduces self discharge to 20% in 3 years ?? versus 1 year. Only a few makers can do it well. In the USA, I've had luck with a Chinese brand sold here as Tenergy.Insure you use a good charger. Key is for batteries never to exceed 45oC during charging, regardless of mode or charge current. The Maha C9000 I use keeps nearly all charging under 40oC, typically 38oC and the BC900, BC700 and BC9009 etc., sold in the USA by La Crosse I've had mixed success; I own both and use the BC900 only in low current mode. It tends to overheat [ see Amazon reviews] if not melt down, when using high currents, not so the Maha. Also it does not do engineering quality tests: IEC capacity test nor a pure discharge test is absent in the BC series.