Arduino 2*3 W Mini Amplifier Circuit - Pam8403 - 5 Pcs

Hello sir, it is 1.8 centimeters by 2 centimeters.

Hello sir, let's answer your questions in order:4 Ohm 10W Speaker: It will work, but since our amp outputs a max of $3W$ per channel, you cannot get full performance (loud sound) from the speaker. The sound level may deteriorate after a certain point. 3.5W or 3W Speaker: Yes, these are the most ideal speakers for this card. It works very efficiently with $3W$ to $5W$ speakers and you will get clear sound.Bluetooth:No, this board is just an amp board, no built-in Bluetooth. Audio input via cable (AUX, etc.) you need to do.Important Note: This board runs on $5V. If over-voltage is applied (e.g., $12V$), the board will be damaged immediately. It is very convenient to power by USB or Powerbank.

Hello sir, The PAM8403 board runs on 2.5-5.5V DC, a single-cell 3.7V Li-ion or LiPo battery is suitable, and the battery is 4.2V when fully charged. The battery is not charged directly through the amp board. For charging, a TP4056 protected charging module suitable for 1S batteries should be used. Ensure correct polarity is observed, and the amp load should be disconnected during charging.