i have been over and over this for several days and i think i just need another pair of eyes.
does anyone see anything incorrect about this circuit that owuld make it not function/ sometimes overheat, sometimes catch fire.
i had 3 of these made and its definately the first prototype where i built 3 and all of them didnt work, im down to the last two boards and im wondering if it is just something i overlooked or if i have something flat wrong.
ps i do realize that R20 is pointless, the original schematic called for it, but another schematic said straight to ground. not sure which is right but the way the boards are made i just leave it unpopulated.
As I do not work with these devices often, trying to follow a schematic against the manufactors' datasheet and best-practices and reference circuits would be most difficult.
Prototypes that overheat are complicated; I've been there. Generally, I would setup my lab power supply(s) to limit current/voltage and power-on using my fingers to gauge any component that is overheating (yep, a few blisters quickly suggested a better method would be beneficial.)
So, a few years back, I gave myself an IR camera. Now, I can find heat signatures that differ by 1C degree. This instrument has been nearly invaluable as I constantly find uses for it. Now, I'm not suggesting you go out and buy an expensive instrument, but consider you "may" already know someone with one that would allow you to use overnight: heating-air maintenance folk, building maintenance, home-inspectors, automotive mechanics, airplane engine repairs, etc.
Have you a DMM?
If so, did you do some basic voltage measurements around your failing circuits to check power supplies, gnd and signals?
Can you please post Exported images of both sides of your PCB?
Did you make a prototype on protoboard or strip board first?
Thanks.. Tom..
PS. On your schematic PLEASE give your components names, like DC-DC module etc, what are U4, U1 and J1, a bit more info than just part numbers please.
What batteries, what voltage, they should be included in the schematic for troubleshooting.
The dw01a is supposed to be a battery protection circuit, it uses the fa8205a MOSFET to lift the ground and disconnect the battery, both of these have overheated and I have also set a MOSFET on fire the max17043 is a i2c battery state of charge circuit it is supposed to read the battery status and state of charge . It doesn't even come up when you scan for it in i2c scanner, but it doesn't over heat . It just does nothing . It is built the way they show the sparkfun adapter.
The tp4056 is a battery charging circuit it has 2 LEDs on it to indicate when it is charging and discharging ... Niether works , one of the 3 I built this over heats the other two just do nothing .
Power and ground are present at all power/ground locations
The component names are on each part, the schematic software uses u1 for the purpose of PCBs silk screen name but the actual device is identified in the schematic
The voltage part however is my bad , it's a lipo circuit 3.4 to 3.7v marginally
Bb1 and 2 are buck boost converters , they are just header mount points were after the bas circuit is assembled they can be install bst is a boost converter none of that is installed currently for testing as they are the load of the circuit .
J1 is mislabeled , right under the j1 it says tp4056 which is the charging controller , j2 8s a USB input connection , so that I later have the option of charging independently in case I decide to use it stand alone ...
The fs8205a is a MOSFET... The diagram has headers for batteries as the circuit itself contains no batteries , butting the battery in the circuit would result in netlist errors
i want it to perform the basic functions provided by the chips, protect the lithium ion battery, charge the lithium ion battery, and monitor the lithium ion batteries SOC (State of charge)
there is nothing to control out side of monitoring the SOC, which is done over i2c to the arduino.. this was supposed ot be my design for an end all be all battery solution for the arduino and other projects i have
Hi,
Can you please post jpg EXPORT images of your PCB, both sides.
When you got your PCB, did you apply power to the battery terminals before fitting components (naked PCB) to check that you had supply in the right places.
Did you do the same with a power supply to the charger input terminals?
Can I suggest you then build the charger part ONLY and test if it works,( you may have to put a short in place of the isolating MOSFET.
Then ad the battery monitor switch and try that, then add your I2C part.
I hope you are using a current limited power supply as the charger source and some low Ah batteries.
Thanks.. Tom..
PS, On your burnt boards is it possible to find which particular tracks burnt up?
when i built the third one i did this and learned that without the protection circuit the charging circuit wouldn't function, and i have tried the i2cpart all by itself and i still have nothing.
i have a bench top power supply and the batteries are old recycled vaporizer batteries from disposable vapes.
two problems i had with this thus far, that i have found is i was missing a ground, for the tp4056 charging circuit, and the state of charge chip only works when the battery is plugged in, which makes sense and was not very well thought out by me in the beginning, i have reworked the board design and await the production and shipment of them i wil let you know if problems persist beyond that. the final problem i now have is the battery charge indicator chips are freaking clones and digikey doesnt have them in stock which is why i bought them elsewhere in the first place. useless clones at that..
