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Groups > sci.electronics.components > #6185
| From | rickman <gnuarm@gmail.com> |
|---|---|
| Newsgroups | sci.electronics.components, sci.electronics.design |
| Subject | Re: Li-Polymer Batteries |
| Date | 2017-10-17 23:36 -0400 |
| Organization | A noiseless patient Spider |
| Message-ID | <os6i7j$dkq$1@dont-email.me> (permalink) |
| References | (6 earlier) <os4ls7$1h6c$1@gioia.aioe.org> <os4m9d$971$1@dont-email.me> <os5kfo$rlg$1@dont-email.me> <os5s5e$nu8$1@dont-email.me> <os6gc3$4k5$1@dont-email.me> |
Cross-posted to 2 groups.
mike wrote on 10/17/2017 11:03 PM: > On 10/17/2017 2:19 PM, rickman wrote: >> mike wrote on 10/17/2017 3:07 PM: >>> On 10/17/2017 3:33 AM, rickman wrote: >>>> Jan Panteltje wrote on 10/17/2017 6:26 AM: >>>>> On a sunny day (Tue, 17 Oct 2017 06:18:09 -0400) it happened rickman >>>>> <gnuarm@gmail.com> wrote in <os4lda$4hi$1@dont-email.me>: >>>>> >>>>>> Jan Panteltje wrote on 10/17/2017 5:47 AM: >>>>>>> On a sunny day (Tue, 17 Oct 2017 05:21:15 -0400) it happened rickman >>>>>>> <gnuarm@gmail.com> wrote in <os4i2d$cgp$1@dont-email.me>: >>>>>>> >>>>>>>> Jan Panteltje wrote on 10/17/2017 4:13 AM: >>>>>>>>> On a sunny day (Tue, 17 Oct 2017 01:30:45 -0400) it happened >>>>>>>>> rickman >>>>>>>>> <gnuarm@gmail.com> wrote in <os44i7$p0f$1@dont-email.me>: >>>>>>>>> >>>>>>>>>> rickman wrote on 10/16/2017 10:16 AM: >>>>>>>>>>> I'm looking at buying these batteries for a test project and >>>>>>>>>>> they ask the >>>>>>>>>>> buyer to choose between battery types 357090 & 357095. I can't >>>>>>>>>>> find any >>>>>>>>>>> references anywhere that describe what these model numbers >>>>>>>>>>> mean. Anyone know? >>>>>>>>>>> >>>>>>>>>>> http://www.ebay.com/itm/201761814378 >>>>>>>>> >>>>>>>>> It has build in chips to protect it, very unlikely to cath fire if >>>>>>>>> you use a decent charger chip. >>>>>>>> >>>>>>>> "Very unlikely" is fine when it is sitting on your desk. If that >>>>>>>> happens >>>>>>>> you get an appropriate fire extinguisher and put it out or at least >>>>>>>> let it >>>>>>>> burn and put out anything else it has ignited. If you are in a >>>>>>>> vehicle >>>>>>>> where you have no means of escaping and no way to deal with the >>>>>>>> fire, you >>>>>>>> are SOL. "Very unlikely" isn't good enough for me. >>>>>>> >>>>>>> Na, wrap your nuclear plants in .. >>>>>>> >>>>>>> >>>>>>>> Also, I'm not convinced all of these units have protection. The >>>>>>>> two model >>>>>>>> numbers would seem to indicate one is 5 mm longer than the other. >>>>>>>> I expect >>>>>>>> this is exactly the size of the protection board, so one might have >>>>>>>> protection and the other might not. It is not all that unusual for >>>>>>>> an eBay >>>>>>>> listing to contain errors and complete lies^H^H^H^H^H alternate >>>>>>>> facts. >>>>>>> >>>>>>> True, I only looked at the link, you can see the protection board, >>>>>>> I have some like that, but only 1000 mAh, marked 'Varta'. >>>>>>> From China nevertheless. >>>>>>> >>>>>>> I have some without protection board too...more RC type single cell >>>>>>> lipos. >>>>>>> And then I have the 3 cell ones, 30C ... no protection either. >>>>>>> Danger all around me, >>>>>>> Oh and the box with LiIon super powerfull forgot how many C. >>>>>>> >>>>>>> Gotta run :-) >>>>>>> >>>>>>> Think about it, you find lipos everywhere, even in those blutooth >>>>>>> earplugs / >>>>>>> headsets for your cellphone, and happily plug it in your ear and >>>>>>> wear it on your head. >>>>>>> Cars have gasoline, bad things can happen... >>>>>>> There is a mad dog president in control of the button, I would worry >>>>>>> about that first. >>>>>>> Probabilities. >>>>>> >>>>>> I seem to recall a number of professional designs from companies who >>>>>> have >>>>>> much reputation to loose which burst into flames. >>>>> >>>>> Was it not Liion? >>>>> >>>>> >>>>>> >>>>>> So no, I don't have tons of confidence in Lithium batteries to the >>>>>> extent >>>>>> that I want to strap one on my kayak with no physical protection >>>>>> against the >>>>>> boat catching on fire. >>>>> >>>>> Well just roll. >>>> >>>> I seem to recall Lithium doesn't do so well in contact with water. >>>> >>> Interesting to see how far people will go to ignore the total system >>> and focus on one ill-conceived component. >>> The devil is in the details, and we have few. >> >> Not sure what you mean about ignoring the "system"? >> >> >>> Do the math. >>> How much energy is released in a battery fire? >> >> A lithium batter will release a *lot* more heat than just what is stored >> in the battery. Even discharged lithium batteries have to be stored >> safely. > Yes, you understand the problem...but what's the number? > I suspect you can't contain a fire in any container you're willing > to paddle around in a kayak. Depends on that number. 42 >>> If you insulate it, how hot will it get inside, since you've >>> guaranteed thermal runaway? >> >> Don't care, the concern is to prevent the China syndrome where the >> battery burns its case and melts though my boat. High density >> polyethylene won't stand up to a lithium fire, or any other type of fire >> for that matter. >> >> >>> How much energy is released as heat if you discharge the battery >>> at maximum current allowed by your current limit strategy? >>> What does that do to the cell temperature if you insulate it? >> >> The unit won't be drawing the maximum current. There will be protection >> to prevent this. The load will be relatively light compared to the C >> value. I'm interested in a long discharge time. >> >> >>> How often are you gonna use this kayak device? >>> Can you not throw it overboard if it catches fire? >> >> Not very easily. It will be securely affixed to the bow of a 17 foot >> kayak with me in the middle. My arms aren't 8 foot long. > > Ok then that's something you can change in your "system approach". > > slight modification of the requirements can make a huge difference in the > "system" solution. Yes, changing the problem can make the solution much easier to find. So what change are you proposing? The way you talk, you sound like you are familiar with formal project management. What drives the requirements in the systems you work on? >>> I submit that the release mechanism is far more likely >>> to jamb than the battery is to catch fire. ;-) >> >> A great reason to prevent a fire from becoming catastrophic. >> >> >>> Given your paranoia, might a NiMH or Alkaline AA cell pack >>> be more cost effective and weigh less and take up less space >>> than your protection vault and fire suppression apparatus and floating >>> burn unit to treat the injured? Maybe you should have two burn >>> units just in case one of the doctors has a heart attack. >> >> That would be a good idea, but NiMH cells don't have the density. But >> that might not be a significant issue. > Looking at the overall system requirements can reveal if this is a viable > option. It does address your major fear. It's all about the weighting > of constraints. Was it the Rolling Stones???You can't always get what you > want.. > But the circuits to use NiMH in >> a device like this aren't so common. > Do you care what's common? You building more than one? > If you can accommodate the voltage variation of lithium, you > can probably figger out how to substitute Lithium. I recall someone's tag line saying engineering is about making what you need with the materials you can get. In this case I am not looking to design a board and solder chips. I wish to use commonly available and low cost board level components to fabricate this system. So yes, I care what's available. What's common usually means low cost. So I care about that as well. So far I have not seen a single board that will serve as a power bank using a single NiMH cell the way I can with a lithium cell. I don't see where you are making any effort to help. You seem to want to nitpick rather than assist. I was hoping someone here had been down this road and could help with recommendation of what to use or what to avoid. -- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998
Back to sci.electronics.components | Previous | Next — Previous in thread | Next in thread | Find similar
Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-16 10:16 -0400
Re: Li-Polymer Batteries Mark Storkamp <mstorkamp@yahoo.com> - 2017-10-16 12:47 -0500
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-16 20:49 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 01:30 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 02:28 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 08:13 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 05:21 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 09:47 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 06:18 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-17 10:26 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 06:33 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-17 15:31 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 16:52 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 07:12 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-18 04:58 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-18 09:29 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 16:53 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 07:12 +0000
Re: Li-Polymer Batteries mike <ham789@netzero.net> - 2017-10-17 12:07 -0700
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 17:19 -0400
Re: Li-Polymer Batteries mike <ham789@netzero.net> - 2017-10-17 20:03 -0700
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 23:36 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-18 17:49 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-18 16:42 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-19 09:11 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 10:53 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNa0nStpealmtje@yahoo.com> - 2017-10-19 15:22 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 12:18 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-19 16:47 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 18:34 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 07:48 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 04:56 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 09:38 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 12:47 -0400
Re: Li-Polymer Batteries Jan Panteltje <pNaOnStPeAlMtje@yahoo.com> - 2017-10-20 17:00 +0000
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 13:45 -0400
Re: Li-Polymer Batteries krw@notreal.com - 2017-10-20 20:05 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 22:54 -0400
Re: Li-Polymer Batteries krw@notreal.com - 2017-10-20 23:03 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-20 23:23 -0400
Re: Li-Polymer Batteries krw@notreal.com - 2017-10-21 10:48 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-21 14:53 -0400
Re: Li-Polymer Batteries krw@notreal.com - 2017-10-21 19:49 -0400
Re: Li-Polymer Batteries Jasen Betts <jasen@xnet.co.nz> - 2017-10-27 22:47 +0000
Re: Li-Polymer Batteries krw@notreal.com - 2017-10-27 22:25 -0400
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-19 12:51 -0400
Re: Li-Polymer Batteries Tom Gardner <spamjunk@blueyonder.co.uk> - 2017-10-17 21:05 +0100
Re: Li-Polymer Batteries TTman <kraken.sankey@gmail.com> - 2017-10-17 16:02 +0100
Re: Li-Polymer Batteries rickman <gnuarm@gmail.com> - 2017-10-17 17:37 -0400
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