FEDEVEL
Platform forum

moko , 09-14-2025, 03:13 PM

im unsure about the U4 vbat connection, someone told me its wrong because vbat is connected directly to vbat.

FuzzyOtter , 09-14-2025, 03:18 PM

Here's a hint: Where is your "input" voltage for the circuit? Where should it connect to on the battery charger IC?

moko , 09-14-2025, 03:23 PM

theres two inputs

moko , 09-14-2025, 03:23 PM

one from usb and one from u3

FuzzyOtter , 09-14-2025, 03:26 PM

What is U3

moko , 09-14-2025, 03:27 PM

battery

FuzzyOtter , 09-14-2025, 03:27 PM

Ok, great. Now think carefully about how you have the battery connected.

moko , 09-14-2025, 03:28 PM

to two converters yea it doesnt really make sense

FuzzyOtter , 09-14-2025, 03:28 PM

...did you design this?

FuzzyOtter , 09-14-2025, 03:28 PM

You're not really understanding the question it seems. What charges the battery?

moko , 09-14-2025, 03:28 PM

kind of

moko , 09-14-2025, 03:28 PM

the usb

FuzzyOtter , 09-14-2025, 03:29 PM

So what should the USB be powering?

moko , 09-14-2025, 03:29 PM

the battery?

moko , 09-14-2025, 03:29 PM

so

FuzzyOtter , 09-14-2025, 03:29 PM

No

moko , 09-14-2025, 03:30 PM

yea it still needs to convert the voltage

moko , 09-14-2025, 03:30 PM

to 3.3v

FuzzyOtter , 09-14-2025, 03:30 PM

...also no

FuzzyOtter , 09-14-2025, 03:30 PM

Do you typically connect a battery directly to the 5V of a USB port?

FuzzyOtter , 09-14-2025, 03:31 PM

You currently have a battery charging IC in your schematic that does nothing

FuzzyOtter , 09-14-2025, 03:31 PM

Look carefully

FuzzyOtter , 09-14-2025, 03:31 PM

Read the datasheet for the thing

QDrives , 09-14-2025, 03:53 PM

Style is way more important than some may believe.
The drawing style of this schematic doen not make the working clear and allows mistakes to happen.

Use space to make things clear.
Do not overlap things: lines over symbols, texts on top of each other.
Try to give the general flow from left to right, be it power or signals.
Draw the schematic on grid of 100 mil.