# Consistent Current Output From Batteries To DC Motors

I'm new to ECE and as a beginner project I've taken apart an RC car and attached an Arduino to the DC motors with an L298N module for control. The goal is for the car to drive a certain path with pre-programmed instructions. Everything is working, but I've noticed a constant drop in current (measured with a multimeter) as the motors run. This results in a lot of variance in the path the car takes. I'm powering the L298N with 8 double A batteries and powering the Arduino with a separate power supply.

Is there a way I can ensure that both motors receive steady current? If there is a better way to have the RC car consistently follow a set path or just tips you have for a beginner I'm open to any suggestions.

• Feedback is the secret to success when it comes to controlling anything. Never assume that your instructions are going to do the same thing every time; have some way of measuring what they do instead. Instead of saying "run for five seconds", say "run until the wheels have turned thirty-eight times" or, even better, "run until you reach this location", where you use some form of sensor to determine when you've reached the location. Jan 17, 2019 at 17:06
• Additionally, AAs are simply not going to cut it for driving motors. There's a reason motorized toys (at least in the 90s and 00s) use C and D cells: they can provide a lot more current for a longer period of time. Jan 17, 2019 at 17:08
• Could you edit your question to describe your mechanical arrangement a bit better? I take it that the car uses skid steering (i.e., there's a right motor and a left motor, and you turn by driving the motors at different rates) -- is this correct? Include a picture of the car if it'll make things more clear. Jan 17, 2019 at 17:09
• @TimWescott There are two 5v DC motors, each connected to the L298N module. The front motor controls the steering from the module by alternating positive/negative flow. The same things applies to the rear motor which controls forward and backward movement. Jan 17, 2019 at 17:33
• @Hearth The motors are small 5v DC motors. With the 8 batteries providing 12v would that not be enough to power them? Or would switching to a C or D cell be beneficial anyway in order to maintain current? Jan 17, 2019 at 17:35