Making a 18650 Battery Pack and Voltage questions

_mini · 17 September 2022 09:49

Hello! I have a specific need to make a battery pack out of 18650, it needs 12v and 2a output.
I know there are many ways to make the battery pack, I was looking for ready solution that can

have 3-4 18650 lion batteries
be able to safely balance charge via 5v Micro USB or USB-C port
provide 12v and 2a output, nice to have one spare 5v output.
pre-made shield as much as possible

I came across this 18650 battery shield that provide four 5v 2.2A, and four 3v 1A output.

I wonder if it is possible to safely convert it to output 12v 2a? Any experts can help/advise would be much appreciated! thank you in advance.

4x-18650-battery-charger-and-5v-3a-usb-power-supply

bannerman100 · 17 September 2022 19:00

18650 Li-Ion cells are happy to output a few amps.

For any required output, you can buy voltage booster and voltage regulator modules, fixed voltage or adjustable, very cheaply

Does this unit include the circuit to balance cell charging ? (You can buy modules for this purpose.)

It’s not clear what circuitry the shown battery holder provides. Can you give a link to the unit so that we can see full specs ?

notveryprettyboy · 17 September 2022 19:27

If you want near exact 12v, you’ll need a small regulator. Pretty cheap. But you’ll probably need at least 5 cells to run it unless you boost it. But there may be a ripple on the supply if you do boost.

_mini · 17 September 2022 19:28

thank you for providing the help.
This is the board 4-Way 18650 Battery Holder | The Pi Hut

If a voltage regulator (or voltage step up can help), just wondering how to wiring it with this battery shield - because it only outputs 5v 2a per power source pin.

SparkyFPV · 17 September 2022 20:49

When you say 12v what are you powering and does it need to be regulated?

if not then what about these?

Bobbysmile · 18 September 2022 08:12

Bobbysmile:

If you get one of these, don’t pay £14 when they’re £5 on AliExpress and basically identical (I have some from this seller )

You won’t really be able to wire it off one of these shields, as they run the cells in parallel and boost the voltage to 5V (i.e. 1S4P), you want one that runs 4 cells in series (i.e. 4S1P) possibly 5, and then to regulate that to a 12V output. They’re great for 3.3 & 5V out as you can hot-swap the cells for long uptimes, I use them for running raspberry pi’s in the field.

You can get these cheap 3P 12V BMS boards off eBay and the such. Can’t say I’ve ever used them but they would work for your case but you’d need to solder the batteries or purchase a separate caddy. The amperage won’t be a problem. A decent 18650 can throw out a lot of sustained amps.

Reposted with edit as I had series and parallel back to front and too much time had passed!

_mini · 19 September 2022 14:22

Thank you. I’ve looked into all recommendations and found a possible solution.

I will use this 3s battery holder that includes a BMS for balance charging & protection:

The input usb-c voltage converter can be this one:

I think this is all I need thank you for everyone’s help!