I'm trying to Bild my own boombox with an 2*50W Bluetooth amplifier and 10 18650 cells with 3,4Ah each. I habe bought a tp4056 charging board. The question is if i use 10 betteries connected in parallel and connect the minus and plus to my tp4056 board if it would be able to charge the safely. Or do I need a balance charger?

  • \$\begingroup\$ No need for balancing parallel batteries. \$\endgroup\$
    – JimmyB
    Commented May 17, 2017 at 9:42

1 Answer 1


You theoretically don't need anything, but there are drawbacks:

  • The charging will be 10 times slower compared to a single cell charged from a TP4056

  • A damaged cell will cause the others in the pack to drain and you'll never be able to charge or maintain the pack at full capacity.

  • A damaged cell will also cause even more slower charging.

So if you make sure all cells are good, you should be fine for a while.

  • \$\begingroup\$ Short circuit current can become dangerously (fire) high - fuse each cell with a thin connecting wire / track \$\endgroup\$
    – Henry Crun
    Commented Mar 16, 2018 at 22:50
  • \$\begingroup\$ For standard cells, you can use a 3.15A fuse for each cell. That makes sure no accidents happen. A cell can deliver up to 2A safely, so at above 3 means there's a problem and that's where the fuse comes in. adelaida.ro/images/thumbnails/31/120/… \$\endgroup\$
    – Overmind
    Commented Mar 22, 2018 at 20:38
  • \$\begingroup\$ is there other charging modules like TP4056 for charging multiple batteries in parallel? \$\endgroup\$
    – kit
    Commented Nov 5, 2018 at 5:56
  • \$\begingroup\$ I build myself a 12-slot charger using TP4056s. I can charge 12 cells if the PSU is good quality on the 5V rail. xaeus.wordpress.com/2018/02/14/… \$\endgroup\$
    – Overmind
    Commented Nov 7, 2018 at 12:59

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