Selection and Qualification of  Lithium Ion Battery Manufacturer - Page 1
Forum section: electronics / projects

author: juanfermed
author_rank: Regular Contributor
timestamp: July 07, 2016, 03:42:32 pm
content: Hi guys,Hope you all are doing great. I will appreciate you advice and comments on the following topic I am facing: Criteria for Selection of a lithium ion battery manufacturer. To give you a better understanding about my question, at the company I work for, we are in the design phase of a product that will use lithium ion batteries. We definitely do not want to make mistakes in any sense regarding the batteries. Our systems are used inside the houses of our customers, we take safety very seriously so we want to be sure we source and buy correctly designed and manufactured batteries to put in our systems.For these, the available literature and industry best practice says (at least thats what google has thrown) that there are 4 main areas we must understand, validate and audit:1. Cell Materials and Process Control2. Cell Chemistry3. Cell Design4. System DesignThe thing is that, I am nowhere near of being an expert in lithium ion manufacturing and, for practical purposes, I know simply nothing regarding points 1, 2 and 3, that is basically 75% of what will make our systems safe to the user, and it depends solely on the final manufacturer we decide.So I am looking for advice, knowledge, suggestions related to what standards, processes, aspects or any other thing I should take into account to validate an audit a cell manufacturer. We understand that going for the big names (Sony, Sanyo, LG Chem, etc) is a good start, but anyways we need and must be sure we do not skip anything, even with big names. Besides, there probably is a good manufacturer that qualifies with good battery prices. Literature strongly and firmly suggests we should physically visit manufacturing facilites, regardless of who is the manufacturer, so we will.I hope to have made my request clear and thank any piece of information anyone can add.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 08, 2016, 04:00:20 am
content: To contribute to my own question, I found some documents that give an idea of what I am looking for:http://www.mpoweruk.com/china_batteries.pdfhttp://www.verizonnebs.com/TPRs/VZ-TPR-9810.pdfhttps://www.ecnmag.com/article/2009/12/seek-production-expertise-during-li-ion-cells-selectionThese do provide valuable insight on the kind of information and verifications that needs to be done during manufacturer qualification process. The most dense one being the verizon document, which basically makes clear how to qualify the "Cell Design" aspect of a manufacturer qualification. The mpoweruk document is very interesting read and provides some anectodal information related to "Cell materials and process control".If anyone has any other resource to which I can refer I will greatly appreciate it.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 08, 2016, 07:54:02 am
content: Basically, if you take the safety as seriously as you write about it, you have no other choice than to use one of the few big names everybody knows in the industry, i.e., Sony, Panasonic/Sanyo, Samsung SDI, LG Chem... Practically all proper brands of devices, consumer or industrial, use only these cells!The only other option would be pouring tens of millions $ if not more on a highly experienced and educated expert team and testing facilities, and even this is risky.Visiting a factory can't give you much of an idea if you are not a world-class expert, because the devil is in the small details. Quite the opposite; if the manufacturer allows you to visit and shows you the details (which normally are trade secrets), it's smells like a scam. This "factory visit" business is an integral part of the Chinese poor quality li-ion theater, giving the buyer a nice warm feeling. Every poor li-ion manufacturer has a large factory with expensive looking equipment. Don't fall into that trap. It doesn't tell anything about the quality whatsoever.My best advice is finding a really educated and experienced consultant who can help bring up a few extra names (ofknownquality) besides the ones I listed above. Don't try to evaluate the quality of lesser known / unsure names - it will be too costly, no matter what.QuoteBattery science is very exact and advanced, but it's mostly happening inside these few giant corporations, everything being a trade secret, so it looks that way.

author: cat87
author_rank: Regular Contributor
timestamp: July 08, 2016, 08:22:24 am
content: Depending on how high a number of batteries you;re going to use for your project, you could talk to one of those big companies, get them to do all the qualifications that you require themselves, then finally send you the battery, all be it at a large price, fully certified.For the project that I'm working on, LiFePo batteries are used. These come already certified by Sony (P/N is US18650FTC1), which saves the company a lot of hassle. Maybe you could do the same thing and save you a lot of headache.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 08, 2016, 04:48:26 pm
content: Quote from: Siwastaja on July 08, 2016, 07:54:02 amHey, thanks. Yes, actually one of the ways we are thinking about is talking to battery pack integrator companies which can basically design and sell to us a battery pack, or maybe provide consultant service in our design process. These companies are already "Authorized Battery Assemblers" for big names, so 1) they have access to reputable cell manufacturers and 2) Cell manufacturers have certified they can design safe battery packs or assemblies.Nonetheless I think several "unknow" (I dont know if "small") battery manufacturers like BAK, Liyuan or others are already providers for big names like Sony, Apple, Panasonic, etc and have passed their qualification programs. Those might me more "accesible" companies for us.That being said, we do take safety very seriously and make this a company wide concern. I totally agree with you about the risk involved. Have you been involved in the past with these? It sounds that you already know all that "factory visit" trap.Quote from: cat87 on July 08, 2016, 08:22:24 amI think our volume is still not big enough for that, unluckily. So the idea you propose sounds interesting, mainly to make all that qualification process transparent to us. So you buy directly from Sony or via a "distribuitor" ?

author: Siwastaja
author_rank: Super Contributor
timestamp: July 08, 2016, 08:12:45 pm
content: Quote from: juanfermed on July 08, 2016, 04:48:26 pmNot personally, but I try to hide my laughter every time someone brags about their "connections" to the "battery industry" and their "trips to China" when they have visited some ThunderSky/whatever factory/facade.

author: ez24
author_rank: Super Contributor
timestamp: July 09, 2016, 05:58:50 am
content: Quote from: Siwastaja on July 08, 2016, 08:12:45 pmOne good thing about a factory visit is you can get what you want. You just tell them what you want and that is what they can print on it. In other words they will tell you what you want to hear. They are the greatest bullshitters in the world.

author: Desert Leo
author_rank: Newbie
timestamp: July 09, 2016, 01:59:50 pm
content: Quote from: juanfermed on July 07, 2016, 03:42:32 pmIMHO, your approach is wrong. My bad experience in last 10 years with thousands of Li-Ion and Li-Ion-Pol batteries is:- One exploded Li-Ion battery, most probably shorted (positive terminal is connected to case) to grounded metal box of device.- One burned Li-Ion-Polymer battery pack of 3 serially connected batteries, most probably wrong charging voltage.- Few inflated Li-Ion batteries - aged delivery lot.Everyone carry at least one such battery in the pocket, bag, car, ... (phones, tablets, laptops, car video recorders, etc.) and only few cases of burning laptops were recorded. Few years ago it is was very hard to find a battery with protection circuit, now is very hard to find without.To check manufacturer's materials and technology is same as to check restaurant's kitchen before to order a dish - no one let you to do that.Most of big names (Sony, ...) do not produce batteries.So:1. Check first is your device. Even the best battery could be damaged in bad developed device.2. Avoid serial and especially parallel connection of batteries.3. Check every battery - O.C. voltage must be at least 3.8V. More is the best. Check also battery protection circuit with charging and discharging with high current.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 11, 2016, 03:13:53 pm
content: """"One good thing about a factory visit is you can get what you want. You just tell them what you want and that is what they can print on it. In other words they will tell you what you want to hear. They are the greatest bullshitters in the world.""""Wow really? This makes me feel I am definitely not the right person to make such a verification. This makes more clear what Siwastaja said about having a very well educated team making the visit, otherwise its useless (which in this context means dangerous)... I feel I can be fooled very easily since I am practically ignorant of Lithium Ion Manufacturing. I am astonished, is it really like that?!!! We have contacted only for "fun" lets say, some really unknown chinese battery manufacturers... I think I better take with a lot of caution what we have shared via email.Quote from: Desert Leo on July 09, 2016, 01:59:50 pmThanks for the advice. Definitely I agree with you with most of what you said. We are taking a (fancy word: ) holistic approach to this, and system design is one of the aspects we are getting deep into. As you said "the best battery could be damaged in a bad developed device" and it is also true that the best device can be damaged by a bad developed battery. So we are trying to cover all aspects from battery materials to the design of the system that will use them.That being said, we are following industry best practices about using Lithium Ion, from the system perspective -assuming we have qualified cells- (there is quite more literature in this matter): overvoltage @ T, undervoltage @ T, overcurrent, overtemperature, short-circuit protection, cell balancing, different protection levels: secondary and primary, having the battery pack designed professionally for our system (electrically, thermally), and the required certifications and testing.I would disagree on avoiding parallel or serial connection of cells, it limits significantly the design freedom, and it is unnecessary, and can increase cost and complexity and make the system too expensive. With proper management, being somewhat simple for low power systems, serial and parallel connection of cells in a pack can be done safely.I have had a hard time trying to get more information about this process, and have realized it is an extremely huge task for a team that have no previous experience. I think probably the appropriate path I should follow is what cat87 suggested about having already certified cells. Anyone has something to add in this matter? Any feedback is greatly appreciated.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 11, 2016, 03:26:25 pm
content: Quote from: Siwastaja on July 08, 2016, 07:54:02 amI see. I have some previous experience (headaches) with Lead Acid which makes me feel and think it is an inexact science. Getting to know now about lithium ion batteries I can only say they are even more complex. But what you say makes sense, we are a small company trying to make "world-class designs" for the safety of our customers, not a huge corporation with much more broad resources to grab.

author: juanfermed
author_rank: Regular Contributor
timestamp: July 14, 2016, 03:02:56 pm
content: Hi guys,Just wanted to comment on other documents that I have found that give a good perspective on what to do to accomplish the task of designing a safe lithium battery powered system.A Guide to lithium Battery Safety: It highlights the importance of a holistic approach to battery selection and also taking into account mechanical and thermal design. Besides it highlights the importance of adhering to an standard when designing a lithium battery system. It also lead me to other documents:http://www.battcon.com/PapersFinal2014/1%20McDowall%20Paper%202014%20Final.pdfTelcordia GR-3150 Generic Requirements for Secondary Non-Aqueous Lithium Batteries: This document looks extremely interesting since 1) comes from the telecommunications industry 2) Describes "generic" requirements to accomplish a system that is safe and has certain degree of fault tolerance.http://telecom-info.telcordia.com/site-cgi/ido/docs.cgi?ID=SEARCH&DOCUMENT=gr-3150?Designing to Meet GR-3150 – Avoiding the Pitfalls of Lithium-Ion Battery DevelopmentThis document is a paper avaILAble from IEEE Xplore. I ended buying this for 2 reasons: 1) because it is becoming very clear that adhering to an standard when designing a lithium system is a best practice, and trying to invent the wheel again is a bad engineering practice and 2) it was muuuch more cheaper than the GR-3150. hahaIEEE and UL have some other documents related to designing systems with lithium ion batteries:http://www.ul.com/wp-content/uploads/2016/02/Safety_Issues_for_Lithium_Ion_Batteries1.pdfhttps://standards.ieee.org/findstds/standard/batteries_all.htmlI hope this can be of any help to anybody in a similar situation than me.

author: Siwastaja
author_rank: Super Contributor
timestamp: July 14, 2016, 04:11:28 pm
content: Quote from: Desert Leo on July 09, 2016, 01:59:50 pmMaybe it'sexactlybecause all those phones, tablets, laptops etc. use those known-brand cells?It'svery wellrecorded that counterfeit cells do have multiple orders of magnitude more safety problems, as well as "cheap" no-brand products that use random cells.Quote"protection circuit" has absolutely nothing to do with anything whatsoever; also, your claim is clearly wrong anyway.QuoteWut? Sony is (practically) the inventor (or commercial developer) of the modern lithium ion technology, and still a very prominent cell producer.QuoteThis makes absolutely no sense.QuoteThis is utter and total bullshit.