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DIY cheap powerbank (technical suggestions R welcome !)

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ym58:

--- Quote from: Siwastaja on August 09, 2016, 07:14:22 am ---Showing faked graphs with severe misinformation "just as examples to point  else out" is a huge problem, you should never ever do it, especially when trying to teach someone else! People will always refer to such graphs and interpret every piece of information they can get from those, because graphs are powerful format of conveying facts using data. This graph doesn't even state that the voltage information is nonsense, which would be the minimum requirement. Although, it would be easiest to simply use a graph with correct information - but that, of course, requires that you have the correct information, which is not true with "Battery University". I guess the author just simply thought that li-ion cells are discharged down to 1V. From the charging algorithm point of view, the starting voltage is an extremely important parameter - a cell starting at 1.0V doesn't go though that kind of charging graph at all.

--- End quote ---
Actually, there is a second graph just below that one on the same page, did you see it ?

Siwastaja:
That graph looks less wrong and more realistic, although many [new] cells today perform better, i.e., reach much more than 60% at the end of CC even at 1C charge.

That being said, even this graph shows the starting voltage clearly at or below 2.5-2.8V, which would most likely cause the real charging algorithm to go to the "conditioning" mode (or simply report "broken cell" and refuse charging), so even this graph is wrongish, although not catastrophically so.

qnh:
I think we are getting a bit off topic ... being obsessive on why we should NOT let any Lithium battery discharged under 3 Volts is sort of pointless as it makes sense to everyone here.
I am also interested in finding a chip (preferably a "cheap chip" as ym58 quoted previously) capable of getting one or two Li-Ions/LiPos single cells charged in a decent time (few hours) and also able to provide a min of 2A output current.
What would then be the best alternative to FM9833E ?

crazyguy:
very cheap chip

Power Bank SoC
http://www.injoinic.com/english.html

IP5108
Charger Current 2.5A, Boost Converter Output Current 2.1A
http://www.injoinic.com/doc/IP5108_brief.pdf

http://www.gearbest.com/chargers/pp_421906.html?wid=21
http://www.chongdiantou.com/thread-2357-1-1.html

ym58:

--- Quote from: crazyguy on August 09, 2016, 04:55:00 pm ---very cheap chip
Power Bank SoC
http://www.injoinic.com/english.html
IP5108
Charger Current 2.5A, Boost Converter Output Current 2.1A
http://www.injoinic.com/doc/IP5108_brief.pdf
http://www.gearbest.com/chargers/pp_421906.html?wid=21
http://www.chongdiantou.com/thread-2357-1-1.html
--- End quote ---
That's just unexpected ... there has been so much blah-blah on this thread that I was close to give up finding credible alternatives to the FM9833E chip !
Let me review those specs accurately and I'll surely have further questions to ask you then ...
Thanks to you HK crazyguy ;) for being so concrete after all this claptrap  :-+
Be back soon.

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