First Test Drives of Partially Completed Cart and Pack Charge

When the battery disconnect switch and the key were switched on, it ran! 
No sparks or smoke and no electrical components failed at the maximum pack voltage (charger cut-off) of 58 volts. 

I had found that the Sure Power DC-DC converter was rated to take 100 Volts, but I was not able to find the upper voltage limit of the controller.  The local EZGO maintenance techs didn't know either.  I did find out from the service techs that the regenerative braking system "shunts" some of the current through a big resistor to protect the battery pack.  There is no public information on the settings of how this works.  Does it set a limit on the peak current or battery voltage?  Does it vary with the pack voltage?

Not having all of the parts to install the JLD-404 amp-hour meter or the odometer, I took my Fluke 115 multimeter along on the test drives.

Using the open ended pair of lead wires from the 200 amp - 75mV shunt, the cart was pulling from 15 to 40 amps with instantaneous peaks up to 160 amps during rapid acceleration.  The pack voltage and the individual cell voltages were checked every mile or so. 

To be sure we stayed away from the battery bottom, I put the cart on first charge with the pack at 51 volts. 

This is the EZGO charge port on the front of the seat bench.  The plug-in-adapter was ordered from EVDrives.com for the cord from the new Lithium charger.

Since the pack was at a healthy SOC, the Intelligent charger went directly into constant current at full 10 amps instead of half current and then ramping up to 10 amps.  10 amps is only 0.1 C (well within the battery limits).

 

Here is the charger at 54.5 volts.  At 10 amps the voltage reading is about 1.3 volts higher than the actual pack voltage due to the voltage drop across the cord.

 The back of the charger with the 110V AC power plug and the On-Off switch.

The charger did shut down the constant current mode when it reached 58.1 volts and went into float applying only enough current to hold the voltage.  Average cell voltage was 3.63, just shy of the recommended 3.65 cut-off voltage for Lithium Iron Phosphate cells.

Next posts, installation of the JLD-404 meter and the EX-RAY speedometer/odometer.