Storming Moroso

Another Hurricane is threatening Florida. The race this weekend is in question. We ignore the weather and concentrate on preparing the car.

Top on our list is to improve the cooling of the batteries. It is clear that we are having problems keeping the batteries within the limits Kokam has suggested. As we secure the batteries more tightly (to solve wire chaffing problems identified last race at Homestead Miami Speedway), the battery stack is compressing and closing off the air spaces we had designed in for cooling.

We decide to try and increase the air pressure going into the battery boxes to maximize what cooling we can get. We install an air box that directs the air flow from behind the radiator into the front of the battery boxes. This requires relocating the differential cooling pump.

We also decide to make a change in the software controlling regenerative braking. We have two goals: To maximize recaptured energy and, to allow the driver to use regen at the beginning of a race without having to worry about over-voltaging the cells.

Our old set up was to limit regen to 280 amps and not use regen for the first lap. We decide to allow the full 600 amps but use the inverters to strictly limit voltage. We will start with a low voltage and keep a sharp eye on the BMS voltage reports. We will adjust the voltage limit upwards to make maximum regen.

We do not yet have an optimum solution for charging at Moroso. The shared 110 volt 15 amp outlets are inadequate for serious charging. We can reserve 30 amp 110 volt outlets but even those will only provide slightly less than 10 amps current into the pack. Our main source of power is a Honda 5000 generator. This should provide about 12 amps. Best case, it would take over 5 hours to charge an empty pack. We will need to plan our power usage carefully.