60W DIY BLUETOOTH Speaker 48h Runtime





Introduction: 60W DIY BLUETOOTH Speaker 48h Runtime

I wanted to make one speaker that suits my needs and not spent little fortune on the new branded one.

I wanted a speaker that can play music for a long time and to play that music LOUD.
(and also, not to look crappy :) )

So I used speaker from an old DVD surrounding system and manage to put all the components in the speakers case needed to make a portable, loud, long lasting, bluetooth speaker!

Step 1: Parts That You Need

1. Speakers (2x30w)

2. Bluetooth 4.0 amplifier

3. Switch

4. BMS ( battery protection circuit)

5. Jack for charger

6. Batteries ( 6x18650) from an old laptop

7. USB buck converter to 5V ( I didn't use it but it would be nice to have a phone charger inside a speaker)

Step 2: Holes for the Switch and Power Input

I made 2 holes in the back of the casing, one for the power input, other for the switch.

I glued everything from the inside making sure that there wasn't any air leak.

Step 3: Making the Battery Pack

I used 6 18650 li-ion batteries in 3S2P order. 11.1v nominal and 12.6v max.
and connect the battery pack with the battery protection circuit

Step 4: More Gluing

Step 5: FINISH

I charged it and let it play, and actually it played for 43 hours continuously on the 70% volume.

That is it!

Hope you find this project interesting !



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23 Discussions

Im trying to build a speaker what is the that same as this build but i have a basic knowledge of electrics so how do i arrange the battery like postive and negative and how do i connect them together manny thanks


1 year ago

And what about buttons on the BT-Receiver/Amp module? You can control the loudness of the amp only from those buttons, so you have actually 2 volume controls in series - one for the BT-Chip (which you control from the phone) and the other one for the amp itself. I´m telling it because you have a battery with total capacity of 4400mAh 12v (if they were new). By maximum power (2x30 = 60w) you will draw up to 5 amps + 5-6%, because even D-Class amps are not perfect, so we get only 40 minutes runtime. Sure, I assume you don´t listen to a constant sine wave, but music, so lets take 1/8 of a maximum power draw - 640mA. 6 Hours are not bad:) But you are telling about 48, wow! You need to draw only 64mA from a 4400mAh battery to get a 48 hours runtime! and 64mA by 12v are only 7,7 Watts. Maybe you got this huge runtime just because you haven´t made the amp louder?

The math is based on those 2 formulas:

Battery Life = Battery Capacity / Current * 0.70 (0.7 are external factors like heat, conversion losses etc).

Current = Power in Watts / Voltage

3 replies

I understand the math calculation, and I did the math too, but when I put it to the test in real time, believe me it was a surprise for me too. I did not believe that it actually played for that much time. I don't know the factor, but I will make another test soon and notify you with the results.

Maximum amp draw on maximum volume was only 1.5 A

The speakers are 30w but I believe the speaker amp board is only 25w x2. They are advertised as 50w x2 but are only 25w. I will say, I'm using a 12v 9800mAh battery from eBay and I have well over 48 hours of playtime on mine.

Help me understand something here. I have basic electronic knowledge but no speaker knowledge really. So I assume you say it is 60w because of two 30w speakers. I assume that 30w is the actual max wattage the speakers can handle but that Power to each. Your amp can push 50w to each but likely is not. I assume you are pushing actually only 7 w total based on the 5v and 1.5A (IV=P) for 3.5w to each speaker. It seems like you get plenty of sound out of the speakers at 3.5w. Why in the world would such small speakers be designed to handle 30w and holy crap would that not be crazy loud??? How come you are not pulling closer to the 50w per channel capable of your amp? Is that because the input power is so low considering it is blue tooth transmission?

WONDERFUL project by the way. I just like to learn and understand so I can build and repair things.


I opened an account, just to let you know how very much I was impressed by your video and soldering skills. What a great job! Thanks.

1 reply

Great job. .can you post links to where you got your main components...I know it is easy to find similar on ebay; but your one have actually worked well...

7 replies

Hi, can you please re post the link for the battery charger? Thank you

Hi, i mean the link of the charging board you used from ebay. You provided above the ebay link on the modules but for not working on the last one. Tried to search but cannot find 12volts. Thanks

Thanks! - How about the power input connector, that matches the charger? Do you have a link for that? - what size matches the charger?

Nice project.

Where could I find a wiring diagram?

Thank you.

1 reply

So the bms is used to charge the batteries and prevents over and under charge?

1 reply

Exactly, but also you will need a corespondent charger for lithium batteries.

The design is amazing! Great job :)