Taming Lester 10

Still an ongoing project.

Today Lester got "C".

Capacitance that is...

After posting that the AC component of the charge current seemed to be a problem, TMAX sent me a box with four 740 mfd, 250 volt electrolytic capacitors to smooth out the fluctuations. Over the last couple of weeks, I've dabbled at getting them installed, and this afternoon connected them using a cut-out square plate of copper for superior current handling capability. The caps are connected to the charger output using #8 wire.

Not shown is the 30,000 ohm, 5 Watt wire wound resistor that I have to install to act as a safety bleeder to insure that the capacitors don't hold a charge when the charger is turned off and disconnected from the battery pack. 2960 mfd of caps charged up to 130+ volts would be enough to throw you to the ground if you got hold of it accidentially.

Looking at the output on the oscilloscope without the capacitors, I see a nasty 78 volt alternating current ripple riding on top of the DC charging current. With the caps in the circuit, and powering a 100 watt light bulb, there is only a .745 volt ripple. Of course, this will worsen when the charger is being required to supply more current into a battery, but I'm hopeful that the caps will help lessen the heating of the conductors when charging vehicles.

If there is still an issue with the wiring heating up, TMAX also sent me a long hank of #6 twisted pair wire that I can substitute for the #8 that is on the output of the charger now.

Part 11