Quick Charge Battery Charger Conversion on 2005 GEM

When the Chinese made Delta-Q battery charger in our 2005 GEM failed after only four years of modest use, I considered all the repair / replacement options. Factory repairs are by contract with GEM, so I can’t just send the charger to Delta-Q in British Columbia, Canada. In the event the unit was not repairable, a replacement Chinese made charger lists at about $900. Despite all the good things I’ve read about these, this unit has not been without its troubles. Frequent nuisance faults, overcharging, tripped circuit breakers (it’s on a dedicated line), and a nagging problem with the thermistor have annoyed the vehicle’s operators. So, I looked for alternatives. Quick Charge, a company based in Oklahoma, has been manufacturing its own line of chargers, load regulators, and discharge testers for more than 30 years. While they don’t market a unit specifically for the GEM, there are several which are acceptable for on-board or off-board use. Like the Delta-Q, the Quick Charge units are totally weather and vibration proof along with being programmable for different battery types. The Quick Charge uses an actual transformer to reduce AC line voltage to the 72 volts DC used by the GEM. I see the lack of complex electronics as an advantage in reliability and ease of service. The only disadvantage is that the supply voltage cannot be changed. Delta-Q will run interchangeably on 120-240 volts AC, whereas the Quick Charge, due to its transformer, is restricted to a single supply voltage. The Quick Charge units are, however, available in either 120 or 240 volt versions. Once I decided on using Quick Charge, sizing the unit became the next decision. Literature from Delta-Q lists the output of 12 amps. Quick Charge markets a 10 amp (SCOLVT7210) and 20 amp (SCOLVT7220) version of their 72 volt programmable charger. The ten amp costs about $400 and the 20 amp is about $550. I chose the 10 amp unit because of its lower cost and the sporadic use of the vehicle. If the vehicle were subject to longer trips, hills, and cargo use, I would have gone with the 20 amp unit. When received, the unit was well packed, came with good instructions, and was easy to install and program. My initial fears of transformer noise were unfounded as the unit is very quiet and nothing like the old time Lester golf car chargers were. The unit was mounted inside the cab next to the hand brake allowing the charge display to be read from outside the vehicle. One minor drawback is that the display only works when the charger is actually plugged in and further, the original steering mounted display does not function with the new charger. A simple voltmeter would solve this. The single red/amber/green LED will be familiar to anyone with an older GEM that used the Zivian charger. Another matter anticipated was the safety interlock that is eliminated by the new charger. I chose to add a simple normally closed relay that opens the control circuit whenever the charger is connected to line power. The Delta-Q wiring diagram and the GEM manual show which wires must be connected. This is done to prevent an operator from driving away with the cord still attached. Thus far, the new charger has worked very well having saved us hundreds of dollars and several weeks downtime.