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LiPo's: Only the Cheap Die Young — Parallax Forums

LiPo's: Only the Cheap Die Young

ercoerco Posts: 20,256
edited 2013-11-17 20:08 in General Discussion
Is it just me, or do a lot of cheap items with built-in non-replaceable (ha) LiPo (?) batteries die prematurely, whether you use them or not, whether they are fully charged when you let them sit for a while or not? Recently I've had batteries tank in Mp3 players, amplified speakers and one of my $29 Walmart eReaders. I better find my keychain camera and check that out...

Hopefully it's as easy as finding a replacement battery and slapping it in. Do premium LiPo's last longer?

If cheap batteries have known shelf life issues, then:

A) maybe that's why Walmart was dumping the eReaders, and
B) why not make them somewhat user-replaceable?

Comments

  • prof_brainoprof_braino Posts: 4,313
    edited 2013-11-12 18:38
    erco wrote: »
    Is it just me, or do a lot of cheap items with built-in non-replaceable (ha) LiPo (?) batteries die prematurely, whether you use them or not, whether they are fully charged when you let them sit for a while or not?

    ... maybe that's why Walmart was dumping the eReaders, ...

    I was noticing this the other day when I started asking about LiFePO4 batteries.

    * Dell & HP laptops, all my stupid phones, my nexus smart phone, the wife's iCrap, all the batteries start to die after about a year, after two years they don't seem to run at all unless they are on the wallwart.

    * My re-newest fav the OLPC XO-1 from 2007 has LiFePo4 batteries, and had been forgotten for about a year, and placed back on the charger and forgotten again for about a year. Now, another year later, i'm playing with it again, and its STILL doing just fine.

    I thing maybe the LiFePO4 batteries have something to do with it
  • CuriousOneCuriousOne Posts: 931
    edited 2013-11-12 21:22
    My SanDisk Sansa E250 is maybe 8 years old, used quite heavily (~1 hour daily). LiPo in it works just fine. (but it is removable)
  • Martin_HMartin_H Posts: 4,051
    edited 2013-11-13 06:48
    My son's friend's Dad is a chemical engineer, and he works for a company that makes LiPo's. He took the scouts on a tour of his workplace and explained how LiPo's are made, how they work, and why they fail over time. He said that charging a LiPo to 100% of its capacity causes chemical reactions that result in small amounts of the lithium being unable to give up electrons. Over time this slowly depletes a cells ability to hold charge. So a good charge controller takes this into account and avoids continuously topping off the battery. Even with care each time you charge a battery small amounts of lithium enter this state.

    So it may be that cheaper devices don't use good good charge controllers, but all LiPo's become unusable over time.
  • ercoerco Posts: 20,256
    edited 2013-11-13 09:22
    According to the Nissan Leaf forum, you can extend your battery life by only charging to 80%. In similar fashion, avoiding deep discharge lengthens battery life.

    So overall, the less you use it, the longer it lasts. If you never drive it, it should last forever!

    I'm way ahead of the game with my dormant Corvair in the garage, accomplishing just that. In fact, mine is getting better. An oil leak stopped some years ago. It healed itself, it's getting better! If I wait long enough, it will surely restore itself to showroom condition.
  • PublisonPublison Posts: 12,366
    edited 2013-11-13 10:22
    Had the same dying LI-Ion in my Lenmar Battery Box. I think we bought them for ~$15.00.

    http://forums.parallax.com/showthread.php/123403-9-Volt-2600-Lithium-ion-Power-Pack-from-Radio-Shack-for-five-dollar-Hack-of-t?highlight=Lenmar

    W    ill not take a charge any more, but..it looks hackable.

    Jim
  • CuriousOneCuriousOne Posts: 931
    edited 2013-11-13 11:49
    My sons friend's dad does not works at any fancy factory, but if you take look at datasheet of battery controller IC, you'll be surprised to see that LiIon/LiPo never gets charged to 100%. Controller always leaves some room to avoid formation of metallic lithium, which will cause decrease in capacity, and if got worse - growth of the lithium "needles" which will cause short circuit and fire/explosion. So, when you see that battery is 100% charged, in fact, it is does not.
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2013-11-13 13:06
    Publison wrote: »
    Had the same dying LI-Ion in my Lenmar Battery Box. I think we bought them for ~$15.00.



    Jim

    o.o !

    I have the same one !
    I use it as my Segway low volt bat pak .( the Seg is a 80 ish volt device so its not worth tapping it ) to Run my LED lights and sound sys and the like .
    I have never had a problem with it l.. and I abuse the heck out of it .
    Its runing my lights every day and night when I drive . for the last Year

    I have poped it open and there is a 2X2 cell array but there is slots for 6 cells . so When it does toast Iam gonna pop in 3X2 and get more run time .
  • john_sjohn_s Posts: 369
    edited 2013-11-17 20:08
    Interesting reading to be found in this Master's degree thesis from 2011

    http://drum.lib.umd.edu/bitstream/1903/12381/1/Williard_umd_0117N_12841.pdf
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