Could you explain the use of battery isolators and automatic charge relays in a two battery system and why a DC/DC charger is better?

Isolators “isolate” the starter and house batteries and have a VSR to ensure no draining of the starter battery. The isolator diverts energy to your house battery only when the vehicle battery is at an adequate voltage. However, they are considered dumb chargers and not multi-stage charging potentially reducing battery life.

 ACRs and VSRs are also “dumb” chargers in that they don’t provide your batteries with the specific voltage at the specific times that they need for longer life. Either a dumb ACR or VSR won’t deliver the specific voltage over the various periods of the charging cycle.

DC-DC Battery to battery (B2B) solves the problem so far unaddressed: delivering electricity in a special way (voltage specific over time) to your batteries. B2B chargers are “smart” chargers. Using a smart charger means that battery life is prolonged. We recommend DC to DC chargers over isolators because they protect the vehicle’s alternator and maximize the battery’s lifespan. DC to DC chargers provide a multi-stage charge to the house battery and push more charge current than an isolator.

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