REVA Inside
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Batteries
The batteries used in our sample "REVA i Deluxe" car (manufactured in November 2007) are of type Trojan T-125, nominally 200Ah but only deliver 165Ah at 75A (0.375C) discharge rate. (Under driving conditions, the discharge rate can be as high as 350A, almost every acceleration is between 100-200A, so you can imagine how much capacity you effectively get out). At 0.2C (40A/5h discharge rate) the capacity is 195Ah, at 0.05C (20h rate) 240Ah. Price: Around 125 EUR (plus VAT)
Controller
Our REVA uses a Curtis 1236-5301 AC motor controller (36-48V/350A peak 2mins RMS).
Motor
The REVA is driven by a 13kW Squirrel-Cage asynchronous 3-phase AC motor, hooked directly to the differential on the rear axle with a gear reduction of 9.4:1.
The nameplate on the motor says: 3-Phase Induction Motor Serial No: 7J-87 Max Power: 13.1 kW, 28 Volts AC, 125 Hz 48 Volts DC (Nominal) Part No: 921-00-00 Supplied by: Kirloskar Electric Company Limited, India To: Reva Electric Car Company (P) Ltd.
Charger
The charger is a 2.2kW switching power supply. Here is an example charging curve of a 5.5 hour charge (20:20 to 1:40) from 20% to 99% SOC:
EMS
The Energy Management System readily delivers lots of interesting data through the easily accessable serial port. By logging data and then visualizing in Excel, we can see all the interesting parameters.
Examining the different cell voltages under load is important for detecting weak or unbalanced cells.
