6. Battery Monitoring System
This is not just a voltmeter for a battery but also an electronic “dipstick” that monitors almost every facet of the battery system and warns of any brewing problems. Among the valuable information provided is battery system voltage current being used, amount of energy used and amp-hours remaining, as well as high- and low-voltage alarms and more. Check out the Newmar DCE monitor ($300, newmarpower.com) or the Xantrex LinkPro ($300, xantrex.com).