Your English is OK. I understood everything you asked! My 72V pack of 110Ah lead acid batteries cost me £600 in Britain. (About $900?) A Mini would make a great EV. Without an engine they are light enough. If you only needed the front seats you could easily fit 12*150Ah batteries. You would also have the boot (trunk) space and the engine compartment. You could keep the transmission and use a WarP9 or similar to easily get the performance you need. Using half your battery energy storage, 100Km would leave you only 180Wh of energy to cover each mile (1.6Km)-not enough,I don't think! Do you REALLY need to travel 100Km? Would half that be enough? Your batteries will weigh about 450Kg. Any more weight than this is a lot for a Mini or any other small car. If you use a bigger car and you need more energy storage. Your range is the limiting factor. If you aim for a SMALLER RANGE it will be MUCH EASIER!