Hi all,
You can scroll to the Essence if you want.
Short "me" story:
I'm a newly registered member, in a "trying to figure out arduino" status, being baffled about the possibilities.
My business is computers and Arduino seems a good way to break out of "the box".
I learned about "some" basics in electronics (I understand things like voltage, current, resistors, diodes, transistors, but that's about it)
and about Java programming (a long time ago, so the Arduino environment looks just a bit familiar).
I essentially discovered and received an Arduino board a few weeks ago, and took some time to read the basics on the Arduino website (and successfully practiced some examples mostly by copying and adapting existing code).
I still have to discover a lot of the possibilities.
I also happen to posess an EV (a 2008 150V Nimh Vectrix (http://www.vectrix.com/products/vx-1, but older model); now with about 12000kms on it.) . This fact triggered my curiosity about battery technology, so I started to get into the matter (ie a lot of forum reading).
It seems my beloved vehicle has no battery management system, and one battery pack after another gets destroyed by unbalanced cells (mine survives still, but certainly won't last forever either).
The separate cells with a lower SOC (state of charge) tend to get "reversed charged" and die when the pack is drained beyond a certain point.
(there are other issues like temperature and systematic overcharging, but that aside)
The only system used for balancing is so called top-balancing, where systematic overcharging the whole pack should pull up the lower SOC cells.
ESSENCE
Picture an Electric Vehicle with 102 Nimh cells @ 1,4V (when fully charged) and no "battery management system (BMS)"
I want to avoid that the cells get out of balance with each other.
My first thought was to connect all separate cells to an Arduino (with som I/O extenders?), measure the voltages, compare them and act upon differences. (ie. warn me or something)
I'm afraid that Arduino has a too limited number of Analog inputs to realise that.
So maybe I'll just have to compare groups of cells instead. (accuracy will go down)
I know this is vague, but I prefer to check the main story first. then go on with some details.
I also realize that this may be to big for me as a beginner, but I'm not scared to learn, and I'm not in a hurry.
Am I in any good direction?? Can such a thing be done, and how?
Any help or better ideas are welcome.
Greets
TuRoK