Wednesday, September 2, 2015

New Batteries!

The game of Tetris begins again... I have acquired 456 Enerdel CE175-360 batteries, which I am so far planning to install in a 76S 6P pack. This will mean a jump from 170V to ~310V fully charged. With the current pack, full load (1000A!) would result in ~30V of IR drop across the bus bars, current sense shunt, fuse, and the cells themselves, so really no more than ~130kW of output power. This new pack will see much lower max current (maybe 600A?), and at 6P will be much lower impedance (0.7mOhm > 0.45mOhm) so hopefully much less IR drop (less heat) and guaranteed full power across the pack capacity range. 40kW more power, with a weight reduction would be noticeable!

These batteries are much higher density so the pack can be arranged for better overall weight distribution in the car. It should result in ~50/50 weight distribution. The green box in the diagram below is a placeholder for a Toyota MGR unit to hopefully add an extra 50kW peak motor with regen to the rear wheels.

A Visio drawing of the old vs new pack arrangement is shown below.