I do not at this time plan on using the automatic balancing part, but will instead balance when needed. Those who recommend no BMS recommend manually balancing the individual batteries in the pack. So the batteries must be observed in some way. Opening the three boxes and using a voltmeter is involved and time consuming and cannot be done in most circumstances. While driving and running a load is one of those times.
The [[http://elithion.com/lithiumate-pro.php|Elithion Lithiumate]] is a Distributed system with cell boards mounted on each battery that will send a voltage and temperature reading to the controller box. These cell boards can balance a cell by internally running a .5 amp drain on that individual until it is equal to the lower charged cells in the pack. The Elithion BMS can run a [[http://en.wikipedia.org/wiki/CAN_bus|CAN bus]], control contactors, relays, run warning lights, buzzers, control battery chargers over 3 different ways, control max discharge, estimate SOH and SOC (state of charge) etc.
The Elithion is not a user friendly, plug and play. Not consumer oriented. I knew this coming in. I would not ever use it if I was doing conversions for customers. No simple display options. (some have come up with expensive displays that may or probably work, I don’t like probably) I am using a lap top computer terminal emulation program that communicates with the BMS controller through a serial port with a dongle adapter to the USB on the Lap top. This open source application is called PuTTY. Real basic DOS type. Tiny text, can’t see while driving. But you can, with effort, record some data.