I started building a DIY portbale speaker out of a douk audio tp 3116 and an old pair of sony speakers.

The spec on the ebay site of the amp says that it operates between 12-25 volts, but for the 60 watts sony speakers I would need around 24 volts. So my question is how should I power the amp? I wanted to use 2 gel batteries, but if fully charged it would output around 28v, so i would need a dc-dc converter, and its capacity is small as well, so i thrashed this idea. If I used 18650-s I would need 5-6 cells, (I realised that 20v is enough for what I want it to use) but i dont know how long will it last with this kind of setup. Should I use 2-3 packs in paralell in order to get decent batterylife or it is hopeless to make something this "powerful" battery powered.

Could you tell me what should I do in order to make this project work?


1 Answer 1


You haven't specified how much power the amp is supposed to put out, so apparently anything works.

Use as many 18650 lithium cells in series as you can without exceeding the amp's maximum allowed input voltage when the cells are at their maximum voltage. The more tricky part is keeping track of the individual cells, and stopping before the lowest one gets to a voltage where it would be damaged.

Two car batteries in series might also work, as long as you don't charge them while connected to the amp.

  • \$\begingroup\$ And how could I keep track of the individual cells? \$\endgroup\$
    – Rudi Varga
    Oct 10, 2017 at 11:07

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.