Help needed with powering my circuit with batteries!

Other Hardware General Electronics
1

I'm basically done with this circuit except the powering of it all. I need to power the circuit with some kind of batteries and connect it in someway without anything breaking, all of which I don't know yet. Any help will be appreciated, thanks.

What is used (what needs to be powered):

  1. Arduino Uno Rev3 + Motor shield Rev3 (5v)
  2. DC motor (12v, 726 mA)
  3. Micro Servo (4.8-6v, ~200 mA)
  4. ESP-8622 (3.3v, 70 mA)

Please let me know if I should power something like the motor individually.
And Also, it would be great with rechargeable batteries.

fullsteup
fullsteup1920×1747 258 KB

2

Options could include:

  1. 12V Sealed Lead-Acid battery, like the ones used as backup power for home burger alarms.
  2. 8x AA or C cells. However, with NiMH you may only get ~10V
  3. 11.2V Li-Po/Li-ion pack. Care must be taken when charging these and they need to be protected against over-discharge too.
3

You can use battery protection circuits or dedicated battery management ICs to prevent overcharging, over-discharging, and short circuits.

4

I should probably have said this circuit will be in a rc car

5

don't i need more than 12v for the whole system?

6

From what you have told us so far, no.

7

Shouldn't i just be able to plug a battery in the motor shield then?
here:
image
I basically know zero about electronics and voltage, but you're saying that i only need 12v because that the highest voltage in the system?

8

You can run the ESP-8622 from the 3V3 on the Uno.
I'd have suggested using a 12V servo, but they mostly seem to be 6V.
So 2 * 4 packs of AA cells will give you +12V and +6V approx.

9

Well, that's what it's there for!

You need 12V for your 12V motor. The Uno has an on-board regulator to make 5V from the 12V for itself.

But there could be a problem. Your servo is connected to the OUT6 header, which gets it's 5V power from the Uno's 5V regulator. This could cause that regulator to overheat and be damaged, because of its high input voltage (12V) and because the WiFi module is powered from the Uno's 3.3V regulator, which gets it's power from the 5V regulator also.

Can you get a replacement 12V servo? Then you could power that directly from your battery

10

What if I only power it with 10v from the 8x aa batteries, would the regulator still overheat?

11

Probably, yes.

Whatever power the servo needs, about the same amount of power will be wasted as heat by the regulator.

If you can't find a 12V servo, try a "buck" regulator/DC-DC converter. Set the converter for 6V output and use that to power your servo directly. This type of regulator is more efficient and wastes only 10~15% of the power as heat.

12

could you send me a link for a regulator and also, would i need to hook the servo up to the breadboard?

13

No. If you post a link to a buck converter, I can tell you if it's suitable or notm

No. The breadboard seems pointless in your circuit. You could have used it for the signal level converter (assuming that's what it is) and for the ESP-01 (with a suitable adapter) but you have not used it for those components, so it has almost no purpose.

14

this should be fine SparkFun BabyBuck Regulator Breakout - 5V (AP63357) - COM-21256 - SparkFun Electronics
I know it's 5v but the servo doesn't need 6v. 5v should work just fine.

15

would that regulator work? @PaulRB

16

Yes, that looks suitable.

17

how should i connect it

18

With wires.

1 Like
19

bob
bob1920×1654 282 KB

Couldn't find the exact buck regulator on cirkit so is used another one that does the same. The D7 pin is set to HIGH for the EN on the regulator. Tell me if this would work, thanks.

20

No. Do you remember why I suggested you use the buck regulator? Maybe review the earlier posts and try again.