Your inverter/charger will always produce a good spark when disconnecting and reconnecting the battery bank. Inverters are seldom wired through the power switches. I have made the connection on my 3 100 watt panels and gotten very little spark, but while making connections to battery bank with everything off, including the solar, have always gotten a good spark. This has been the same on 3 different coaches. The manual on my first inverter noted to expect this.
Las Vegas, NV
Had: 2007 Limited SE 40fdts