EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: kfir on March 05, 2018, 01:42:48 pm
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while searcing for li-ion cell charger and protection IC's,
i found this combanation recommended, the TP4056 for charging + dw01-p for protection.
my concern with the dw01-p is the overdischarge protection voltage is 2.4V (typ).
as far as i understand discharging a li-ion battery to 2.4v is damaging to the cell.
and from what i have seen this chip is farly common so it make no sense it would damage the cell,
so what am i missing here?
for this reason i have searched for an alternativ, i found FS312F-G wich has a 3.0V cutoff voltage.
but i cant find it for sell so any suggestion for a cell protection IC ?
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As you say, the DW01 is in very widespread use. In fact, I suspect it is the protection chip installed on most lipo single cells which have embedded protection circuits. When I took one apart, that's what I found.
But you have to remember that in most cases that 2.4v will be reached under load. I did a test at about 120 ma, and while it shut down at 2.38V, after an hour of no load recovery, the cell meaured about 2.85V. Of course that's just one example, but you see what I'm saying. So the 2.4V is probably not as bad as it sounds.
And if you select the other one, shutting down at 3.0V under load may be leaving quite a bit on the table. But I'm not sure it matters because I couldn't find one either.
Something like a MAX809 could be used to trigger a higher shutoff, but that would probably substantially increase costs relative to the DW01.
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The combination i use in the 4056 modules i build is TP4056 or TC4056 (Toppower or FM), FS312F-G as protection IC and i am now testing NCE2007N as the dual mosfet part.
https://datasheet.lcsc.com/szlcsc/TP4056_C16581.pdf
https://datasheet.lcsc.com/szlcsc/TC4056A_C84051.pdf
https://datasheet.lcsc.com/szlcsc/FS312F-G_C82736.pdf
https://datasheet.lcsc.com/szlcsc/NCE2007N_C169816.pdf