Dual voltage system

[SciroccoEV]

I've been thinking about the possibility of a dual battery/voltage system.

Tesla modules are hard to beat for energy density, but packaging more than about 8 of the 5.3kwh modules into a car can be tricky.

My thought was to use a high voltage string of something like the BMW modules straight into the inverter DC bus and a second lower voltage string of Tesla modules on the original battery input, using the Buck/Boost converter to transfer energy between the two.

[rstevens81]

I have been thinking very similar (except with some cheap old Lipo4's) I think this has great potential.
Software wise I don't think it should be very hard to implement (if inverter is in drive and main pack voltage is less than X keep increasing untill current Y limit reached and reduce in the reverse).
the only possible hurdle could be how much current the boost converter can handle continuosly, in theory it should be 27000 KW / 200 volts = 135 amps (I know I'm over simplify but it's a ball park figure) but this is all probably irrelevant as Damian has proven with Toyota stuff test it to find out the real limits are.
I have a spare Yaris inverter that I'm using for parts, before I pull it apart I will do a resistor mod to see if it works at lower voltages, it wouldn't be too soon though as I'm a little busy in the next few weeks.

[SciroccoEV]

The boost converter only needs to handle average power.