LiitoKala charger fault

setithing

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Jan 1, 2020
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2
Hi all,

Been following along for a while now slowly testing cells in the hope of building my own pack one day. Wanted to share an interesting failure of my LiitoKala Engineer Lii-500. Couldn't fine any refrence to this fualt before.

Been test cells fine then one got hot on me about 40degrees from feel of it. Tried anouther and that goes hot and the charger smells burning. That fun electronics are going wrong burning. Opened it up and found what I guess is the current sence resistor burnt and the mosfet shorted resaulting in 12V on the cell terminal.

It does suprise me that nothing worse happened to the cells (bined just in case), first one was in there a while not sure when the mosfet failed. There is a mosfet of the negative terminal but looks like a low voltage cut off (batt+ -> resistive devider -> gate) and a 300mOhm resistor as the only thing current limititing.

Makes for an interesting failure, as I hear moafets tend to fail short. What you could you add to protect to the cell? Do other chargers have similar regulators circuits? I mean this was cheap so there is that.

Tom
 

LithiumSolar

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Oct 8, 2016
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So it was overcharging the cells to 12V?! That's insane...!

Some of the better 18650 charger/testers have built-in temperature sensors to prevent the cells from getting too hot. In the case of charging them at 12V, surely they would have gotten hot and shut down?
 

kc8adu

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Joined
May 22, 2019
Messages
101
protection is null and void if the control element(mosfet) shorts.
this is why you dont charge unattended.
esp with a cheap junky thing like anything liitokala.
 

Overmind

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Jan 16, 2019
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406
Why you say liitokala is junk ?
Their 26650 cells have capacity above stated.
 

LithiumSolar

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Overmind said:
Why you say liitokala is junk ?
Their 26650 cells have capacity above stated.

To start with, Littokala is known for selling counterfeit cells. That's why they all look like common Panasonic or Samsung cells, just with a Littokala sticker. They got caught and called out on it. They might test above stated capacity now, but how is it going to look a year from now? There is a reason they are cheap.
 

Overmind

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Jan 16, 2019
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406
Well, I have some from 1 year ago.
I will retest if needed. They seemed fine when initially tested.
I have both black ones and blue-ish (2 versions: with clamps and normal).
 

Jonisingt35r

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Jul 18, 2019
Messages
114
Hello wonder if anybody had a faulty lii500 as I need a display
Thanks

Well Ive heard otherwise there are vids on you tube about genuine lokola cells :) :) :)
 
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