TP4056 DIY Protection


SLS BATTERY AUCTIONS are now live at www.batteryhookup.com EV, Lithium, LifePo4, Inverters & More

nautal

New member
Joined
Sep 5, 2017
Messages
5
I have read through many post (around 20-30) and have not seen this idea yet so if there was I appologize.

I recently had a bonehead move, inserted a cell the wrong way in tp4056.
I was like wow both red and green light up, so I stuck it in another one same thing
turns out no magic smoke.
Curiously, I stuck another battery hoping that I just burned the led's out and no charging.... :(

DOH!

Here's the question to all more electronically inclined than me.


Could you put a simple diode on the positive side of the between the tp4056 and the battery holder to prevent reverse current and
pulling a "Nautal"?

Or would the reverse current still be enough to fry the board?

Its easier for me to replace the + wire and diode, than the tp4056.

cut 2 ends of a wire... solder a new one in.

vs

remove stupid mistake by solder 4 wires to new board.
 

Korishan

Moderator
Joined
Jan 7, 2017
Messages
7,072
By putting a diode on the TP wouldn't be able to sense what the voltage is. The best way to do reverse protection is to use use two FET's.
However, this can be a bit more difficult/expensive than just buying an already reverse protection board. But, the protection only works on weak cells. If you put a >3V or >3.5V it'll still fry the board.
I would just recommend to make sure you put ur cell in the correct order. After all, like the 1.5V batteries, it has a bump on the pos end, plus there's an indent around the pos end of the cell as well.
If you do use diodes, you would need to add several other components because you'd want to bypass the diode once the cell is installed correctly.
 

egam

Member
Joined
Mar 9, 2017
Messages
109
I had the same question and found a circuit that uses a polymer fuse in series with the battery and a diode across the battery outputs of the top 4056. If you install the battery backwards, the diode allows the current to short across the fuse. This blows the Fuse. Then the fuse resets when you correct the polarity. The diode needs to be a shotkey fast acting diode with a higher current rating than the tpc polymer fuse. It is almost as much cost to protect the tp4056 as it is to replace it. But it will save a ton of aggravation to not destroy your tp4056's.
 

WallBender

Member
Joined
Sep 16, 2017
Messages
41
I'm not sure what actually causes the burn out when hooked up in reverse, but couldn't you put a 2amp or 1.5amp fuse between it and the cell or is it not the current draw that causes the problem? Having some sort of protection would be nice and swapping out a fuse isn't too big of a deal.
 

Korishan

Moderator
Joined
Jan 7, 2017
Messages
7,072
Not current. Just forced voltage in the wrong direction.
This is evident as if the voltage is below like 2V, the TP won't short out and it's ok. But if it's 3.2V or higher (I know this voltage specifically, just not the lower end where it's ok), then it'll blow the TP IC.
 
Top