[DIY Project] Reverse Protected 18650 Lithium-Ion Charging Unit

1N4148 are low power signal diodes & would happily pop to "protect" the fuse....
The symbol used on the circuit diagram suggests a schottky diode ie for low fwd drop in the reverse situation.
You'd want the diode to survive an accidental reverse with associated high current pulse while the fuse blew so it would need to be rated probably 3A for 2A fuse
Something like a 1N5820 might do it.

There's a way to use mosfets as reverse protection, google "mosfet reverse polarity protection"
eg https://hackaday.com/2011/12/06/reverse-voltage-protection-with-a-p-fet/
With this method, the fuse doesn't blow, no current flows so nothing happens.
It might take a low gate voltage type to work best & batteries with low voltage might not work too well or need a kickstart, etc
 
i am using 1.8amp polyfuse, but maybe still a bit too challenging. i do have to test it...

k.
 
Yes, 1n4148 does not work, I grilled the TP ;-)
 
NOOB ALERT! - If anyone is using this PCB, do you mind taking a close up shot (Photo, Video) of the Diode connected to the TP4056 and upload it here/Youtube. Thank you in advance.
 
Thanks for the response Jason, do you mind however uploading a picture of how you connected the Diode to your TP4056. Thanks you in advance.
 
Here is photo
image_xxdwmu.jpg
 
Thank you once again Jason. i now have a better idea on how to set this up. Remember... Noob here
 
ps915 said:
Hey Guys,

I started to design a simple 4in1 PCB for charging 18650 cells while looking at my actual charging rig attached to some wood!

Some time ago, i teached myself to design PCBs for hobby use. I really love PCB Design and started this little project.
Its a 4x Charger protected with a 3A diode and a 2A glass fuse.

I am using this for this porject:https://blog.seidel-philipp.de/xxl-powerhouse-diy-feldakku-aus-18650-zellen/

DOWNLOAD

Features
  • 4A charging current
  • mounting holes
  • easy soldering
  • "clean" Design
  • reverse polarity protection with fuse and diode
  • easy expandable (just connect them in series)


I used the cheapest components to get the lowest price possible.

Estimated costs per board including hardware:
1x PCB $4.9 (you will get 10 boards[img=16x16]https://static.xx.fbcdn.net/images/emoji.php/v9/fb0/1.5/16/1f609.png[/img])
4x TP4056 $0.74
4x glass fuse $0.11
8x glass fuse holder $0.08
4x diode $0.48
1x 18650 holder $0.90
------------------------------------
calculated price: $2.8 excluding possible shipping

real price: $7.21 and you still have 9 PCBs left to build more charges and hook them up in parallel.


What do you think?
Any ideas, tips or whiches?

These was my first design, but i already changed the cables to connect them in a better way!

Outdated:

image_uejrtu.jpg




image_bywpng.jpgimage_mizkug.jpg


Please be aware
I wont sell or ship anything to you, its a DIY project made for the community!
I will just share the files for the PCB and a list of parts used!
You have to solder andorder the PCB from any manufacturer yourself!

Hello,

So I found your PCB on your Blog and it inspired me to build a 40 cell charging board.
I used a DPS 800GB A HP modified power supply a Lexan board ,brass standoffs, and a PWM fan controller with temp probe.
I also supplied each board separately with a 12V to 5V buck converter. Call me crazy but I don'tdrink anymore so I got to do something with my time. ;)



I used the diodes (1N5402) and pushed them through the TP4056

image_fstxoy.jpg

and then used the cut off legs to push through the supply side.

image_azthkx.jpg

for a finished product that looks like this.

image_jpnkvq.jpg


Then I mounted them on the Lexan

image_iyvimw.jpg

added the Fan and etc.

image_fsdfqk.jpg

Finally the finished product.

image_uhwrdm.jpg



Next project is a capacity tester using the same boards as battery holderswhich I will try to modify for the ZB2L3. We will see.


avm131 said:
NOOB ALERT! - If anyone is using this PCB, do you mind taking a close up shot (Photo, Video) of the Diode connected to the TP4056 and upload it here/Youtube. Thank you in advance.

Here you go
image_vdkqyl.jpg
 
ps915 said:
Well, actually the rendering was version one which i never produced. The Prototype looks like this:

you can connect them without these long wires like i did in the rendering!


Is there a way to provide reverse polarityprotection for the TP4056 without a fuse? Many small devices have this feature so how do they accomplish this?
 
wattwenger said:
You can build a curcuit with a mosfet diagram and info here
http://blog.deconinck.info/post/2017/12/22/18650-Battery-charger-reverse-polarity-protection

But I like Philipp's design as it's a good wake up call in the AM (when you see that fuse pop kinda has a satisfying feeling knowing you didn't smoke a TP4056)when you haven't had enough coffee plus we need to keep the chinese fuse manufacturers in business :p.


Wolf
I agree thatPhilipp's design is an improvement and since I have the Gerber file it could probably be easily added to the cheap board. The fuse is less interesting to me although it is a very good solution I would prefer to not need to replace fuses.Philipp's addition could be easily added on a tiny board on the charging output of the TP4056. Ever better would be adding a buzzer when the battery is inserted backward asPhilipp mentions. I'm not an electronics guy so perhaps someone who is could either add this to the gerber file or create a daughter board withPhilipp's improvements.

Cheers!
 
Bubba said:
Has anyone tried the TP5100 with reverse polarity protection?

Hey Bubba! I'm in the Grove. Where did you see the TP5100? I didn't know that existed.
 
The TP5100 is a buck lithium ion CC/CV charger, that can work from 5V-18V input voltage to output 4,2V/8,4V to a 1S/2S battery pack.

The main advantage of using this over a TP4056 are higher efficiency, no worries about overvoltage to the linear regulator, but most importantly, you can use 12V power supplies to power it, meaning you can save on wiring to power the TP5100s, less power losses over the wires, and no need to get big and heavy high amperage 5V power supplies.

It's more expensive, but it is worth it. There are also no counterfeits on the market, since it is much more expensive to produce, meaning no problem with fakes.
 
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