While I was away UPS left some presents

While I was away working in Spain for 2 weeks the UPS driver left a few boxes on my doorstep.  So after unpacking the bags it was time to unpack the new toys:

The first is the EMW EV Android Dashboard.

http://www.emotorwerks.com/emw3/product/ev-dashboard-by-emw-basic-edition/

It measures the current flowing from the pack to the controller in order to estimate the state of charge (SOC) of the battery cells.  Unlike other batter chemistries you cannot estimate SOC from the voltage.  Lithium has a very flat voltage curve from 10-90%.  Great for performance but it's hard to know how many electrons you still have in the tank.  This uses a hall effect sensor to measure the current flow.  It is designed to work with a android device so I was able to get a good deal on a new Toshiba 10.1 thrive tablet.   It has bluetooth to communicate with the current sensor and a GPS chip for navigation and a nice bright screen. It's not the best tablet in general because it's a little bulky and not the most robust case.  But none of that matters for me as I am mounting it in the center dash.

One other cool feature is that there is an output on the Bluetooth unit so it will drive the stock fuel gauge too. 

I need to play with it more but it doesn't seem to work in landscape mode. Hopefully this is something that I haven't figured out yet or will get added soon.  The other thing is that I wish the gauges were more adjustable as far as ranges and it would be really nice to add the option for warning lights (for high batt temp, SOC < 10% etc).  It seems like this would be easy to add but I have only used a android device for 15 minutes....

The second item was my BMS system:

I went with Lithiumate Lite, EV Li-Ion Battery Management System (BMS).

http://elithion.com/lithiumate_lite_overview.php

It monitors each cell group (in my case 3 cells in parallel) and make sure that the cell doesn't get over charged or over discharged.  I went back and forth on needing a BMS and I think bottom balancing a pack that has had the capacity matched would be fine.  But this is my first time with lithium and wanted the "insurance" of the BMS.  I knew I at least wanted monitoring of all of my gray market A123 cells and going to a full blown management system wasn't anymore expensive with the Lithiumate Lite.  Also on the bright side, not only are they made in the US, they are made here in Colorado!

To be honest having the EMW dash and the Lithiumate is redundant but I wanted to try out both and see how they compared.