The I3 Battery is sold and i buy a Smart ED4 Battery-Assamble.
120kg for all three Blocks (17,6kWh) without Housing. Little bit higher (175mm instead of 150mm from the BMW I3 Blocks) and with 430x355mm groundaera a little bit larger Modules. I hope i could squeeze them under the rear trunk, above the Engine.
"Fleck Elektromobile", a lokal EV Workshop, means the Roadster get +49kg empty Payload after his convertion. He use a heavy 60kg asynchronmotor with only 30kW and 10kWh LiFePO4 (wight about 110kg). So my Setup with ED4 Battery and Tesla should weight roughly the same and i had no problem with "overweight"