Problem with 4s protection circuit 18650 and class d amp

[Rorut]

when connecting my fully functional 4s battery pack to my class d amplifier it goes in to protection mode or something. Works fine with power adaptor. And also works fine with another amp. What can cause this? Any ideas on how to make a fix for it?

 

[schmitt trigger]

Do you have a schematic? That would help.

 

[Rorut]

Unfortunately not...

 

[schmitt trigger]

Do you have a link where you purchased it?

 

[Rorut]

It looks same as this one. Bought it more than a year ago.

https://m.ebay.com/itm/DC-12-24V-TP...122800?hash=item1c42391a30:g:a4IAAOSw~CRTp7vS

 

[audioguru]

ebay wants you to buy 5 of those cheap Chinese amplifiers, then maybe you will find one that works properly.
Are the battery cells all fully charged? Measure the loaded voltage of each one, maybe the (cheap Chinese) protection circuit is bad or is connected wrong.
The battery holder might have poor contacts.

EDIT: If the IC in the amplifier is a genuine Texas Instruments TPA3123 then its minimum voltage is 10V and your 4 cells produce only 4 x 3.6V= 14.4V. Maybe your power adapter has a higher voltage, measure it. Edited again.
EDIT again: It might be a Chinese copy of a real TPA3123.

 

[Rorut]

Battery pack is working properly. Used it for several other circuits. It is 18650 batteries. Each cell is 3.6v . Chinese protection has worked fine for over a year. Cells is fully charged with a balance charger. Battery holder has good contacts. It is something with the amp.

Amp works with power 230v , 16V DC supply