Ok Amberwolf, here is one I think you, or one of the gurus, would know. Can I safely connect the 72v and 48v batteries pictured here in series to make a 120v battery? They each have their own BMS and are also different amp output, 100a for the 72v, 70a for the 48v. My controllers are normally set at 300a, for a large battery, but they had me change them to 100a max. for this 72v battery. I really want to try this, but I am too young to die, so expert help would be most appreciated!