Dual Battery Smart Isolator 12v Relay 140 Amp on 2040-parts.com

A smart battery isolator is the ultra-simple and most technologically advanced method of automatic battery isolation. These units can be installed between batteries with a common ground to automatically control the charging process to the batteries but continue to provide isolation when a charging source is unavailable. The small size and rugged construction of these units allow for quick simple installation for even the most novice DIYer. The smart isolator is also “Dual Sensing” which senses the charge of both batteries. If either battery is receiving a charge, e.g. a battery charger is connected to the auxiliary battery; the relay will engage and charge both batteries. The advanced technology always insures that the first battery is fully charged (13.4v) before connection is made to the second battery. This prevents problems that may result from your charging source being too low in amps to charge all batteries at once. If placed in linear sequence between each battery the isolator units can provide proper charging for several batteries in a multiple battery setup such as in larger boats that may have 2 or more house batteries.