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.
If you are planning on buying one you should read this.
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