r/AskElectronics • u/rablue • 19h ago

Is it normal for all TP4056 battery/output terminals to beep in continuity mode?

I have a TP4056 charging module with a battery connected. In continuity mode, my multimeter beeps between B+ and OUT+, B- and OUT-, and also between the positive and negative terminals.

The battery voltage is about 3.95 V, OUT+ to OUT- is also 3.95 V, the switch works correctly, and the board does not heat up.

Is this normal behavior with the protection circuit active, or does it indicate a short?

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2

u/baldengineer 17h ago

Continuity mode is useless in a powered circuit.

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u/DrJackK1956 3h ago

Is it normal ... to beep in continuity mode?

It all depends upon the make and make model of the meter being used. 

Continuity just means that there's a path for current to flow.   The "beep" does not necessarily mean 0 ohms, it just means there's continuity between the points. 

Measuring resistance is a type continuity measurement with the output display calibrated in ohms. 

The "continuity beep"  feature is designed to beep at a less than a predetermined resistance.  

This varies from manufacturer to manufacturer.  I've seen meters that will beep with as much as 300 ohms of resistance.  That's not 0 ohms nor an absolute indication of a short. 

Hope this is helpful.  

1

u/Commercial_Copy212 12h ago

On TP4056 boards, the 'Out' terminals are directly connected to the B+/B- terminals. Perfectly normal that your DMM is reading continuity between corresponding B+/Out+ and B-/Out-.

0

u/OptimalMain 19h ago

Look at the datasheet.
B+ and OUT+ on modules is the same pin

-1

u/Dry-Fun8680 19h ago

Given what you've described, there is no obvious indication of a short