Background: Building a radio control wheel bot. Using a motor controller that recommends independent power supply for 1.) power to the controller and 2.) power to the motors. Also want a 3rd power supply for accessories (lights, horns, etc.).
I am using 8 identical lead acid batteries. 6 in parallel for the motors, 1 for the controller power, and 1 for the accessories. All 3 systems are 12v.
I want to hard wire a solar charger (with controller) to charge the systems, but I will put a switch on all the positive connections to the charger, so I can choose when each system is being charged. I do not want to put switches on the negatives though.
So now the question: Is it ok to connect all the grounds from all the batteries together? Then, if I want to charge all 3 systems at the same time, I will turn all the charging switches on, which will effectively put all 3 systems in parallel. Is this ok?
Is it ok to charge one system while all the grounds are connected? Most likely i will want to charge the controller power and accessory at all times, but only charge the motor batteries when I'm not driving it (to prevent voltage/current spikes from going to the controller power).
Any explanation is greatly appreciated. Thank you!