How to power an arduino robot with one battery?

Question

Batteries

I am assembling a robot on arduino uno, there are two 5v motors, 3 servos. I use a 4 volt battery with a capacity of 1500 mA / h as power. I connect it through a CN6009 voltage converter (I set 7v on it). As an engine driver - L298N. The problem is that when two motors start at the same time, a voltage drop occurs, and sometimes (1 case out of 10) the arduino reboots due to voltage instability. How can this problem be solved? install a voltage stabilizer? Or mb additional capacitor? There is no desire to use a separate battery for arduino

Answer 1

You can try a capacitor bank. You can limit the current in the motors.
Although if it’s 7V, then it’s possible through the diode to the arduino, and in front of it there is a large capacity, so that when the power from the arduino drops, the power doesn’t pull like that.

Answer 2

In a similar situation, I put a capacitor in parallel to the arduino, there were fewer problems with restarting.

Answer 3

The voltage converter is the stabilizer. You have a 2A converter. measure the consumed current. The average current of your circuit should not exceed 0.7A, because. impulse currents at the time of starting the motors are much larger. Measurements should be carried out when powered by a good laboratory PSU. If the average current is large, look for a more powerful converter.
Also, do not forget that the current from the battery should not exceed 3A (this is provided that the battery is branded) i.e. after conversion, taking into account the efficiency of not more than 1.5A
PS Capacitors in the converter are quite decent, no others are needed

Answer 4

Yes, everything is simpler and more reliable, and most importantly, more correctly in amateur radio.
put a power filter (in series from the battery, a resistor ~ 10-50 Ohm and 2 conders: electrolyte ~ 100-1000uF (more is better) and NOT electrolyte for ~ 100-1000 nanofarads, conders to ground) for power supply and input stages (LEGS) of arduins . And only on them. The rest is below:
all stages (including the legs that work as an arduino signal output) must be powered from another place (for example, directly from the batteries.)
Then the power interference will not pass to the arduino is guaranteed. Instead of a resistor (or add it in series, depending on the rating), you can inductance. You can also not one, but 2 filters, etc. after the other. Then you can use the minimum ratings of sums and conduits, only 1 (electric and non-electric) in each filter. and better filtering.
Mustache! feed the engines from whatever you want. Arduino won't reboot.
And yes, supply power to the dviglos and to the arduino with different wires directly from the batteries. Otherwise, power interference from the wires will pass to the arduino.
This is (above) the level of the basics of a radio amateur.
A separate stabilizer on the arduino is also possible (it also works as an active filter against interference), but it’s unnecessary, the filter (above) will not be bad anyway.