Mine is a Terra 720 and suffers badly during transmit when voltage drops below 12v so I have always made 14v packs which are over 3+ years old now and need replacing. Hence the quandary about new Lifepo4's I am in communication with "Dakota" batteries and they are putting a BMS system into there batteries the has cell balancing starting in April sometime. And are selling for about $90 ea for 10 amp hour.