Its in and running at max speed 4800 baud and I have put the battery packs back in the car and been for a 10 mile test drive.
Cells are all within 20mv which is the limit of the resolution. No unexpected errors.
Still some issue with Master software but that's expected.
What Works.
1) Cell voltage measurement and transmission to Master
2) Current sensing & AH counting
3) Charger control Relay & Opto
4) Over/Under Voltage/Temp alarms
5) Individual cell voltage view feature.
What doesn't work yet or untested.
1) Security code feature crashes Master requiring it to be re-programmed so I am removing that for the time being.
2) I2C Temp sensors are ok when engine off but when driving giving eroneous readings due to interference. Need to scope them a bit more. May move them to seperate inputs as I have some spares.
3) Speed/Distance not connected up yet. Code is active in Master though.
So car is back together and driveable. Few minor niggles to sort and re-write some of Master code but it basically works now as I originally intended.
I think the Slave code will stay as is for quite a while now.
The Master code will continue to evolve as I correct the issues and add/remove features.
I will add remote programming of things like Slave Load on/off voltage but at the moment you have to pre-program that in Slaves.
Thanks to all for their help and support on here, you know who you are! This project would not have ben possible without the support, advice and contributions from friends around the world 
Boelle
Probably 25% of my cells would not fit in ipu comp. Theres not that much space to fit a bigger box unless you really hack everything about!!
