Does using a power expander mean we can use a second battery?
Welcome to the forum ibots!
Yes, it allows you to run four motors off of a second battery.
Thanks for your help.
Is that required?
Well no… but you should figure out what you are buying before you spend $50.
ibot,
Similarly optional, but potentially useful, is the Vex Wiki entry at:
https://vexforum.com/wiki/index.php/Power_Expander
Eric