The Battery Manager EL is an instrument panel for an Electrathon Race car. It is powered from the battery pack it measures. It displays battery current, voltage, amp/hours used, and time since the start of the race. It will measure and run on as little as 9V or as much as 35V, and can measure from -50 to 350 amps. It's clock is accurate to within a few seconds in the 1 hour race.
BSDesigns Battery Manager ELs have been used by the Cloud Electric electrathon race cars for several years, and have seldom been beaten. Click here for the story of the 2004 Portland International Raceway Electrathon race!
The Battery Manager3 EV for Electric Vehicle conversion is in production now.
It displays battery pack Voltage, Current, Amp/Hours consumed, and a 40 segment "Gas Gauge".
You can buy them from