Battery Isolators

Battery isolators are electrical devices that allow multiple batteries to be charged from a single charging source, such as an alternator, while keeping those batteries electrically separated from each other. This separation ensures that one battery can be discharged without draining the others. In marine, RV, and vehicle applications, this typically means the engine starting battery stays protected while a separate house or accessory battery powers electronics, lighting, refrigeration, or other loads.

Battery isolators are commonly used to maintain the starting battery charge while using a second battery to power accessory items (sound systems, refrigeration, emergency lights, computer equipment, etc.) eliminating the fear of having a dead battery when trying to start the engine.

Choosing Battery Isolators can be a daunting task for the uninitiated. Consider the following when making your selection:

How many alternators do you have?
How many amps does your alternator output?
How many batteries do you want your system to charge?

Having the answers to those three questions makes choosing the right isolator for your needs a snap.

Common Wiring Setups

1 Alternator 2 Battery

1 Alternator 3 Battery

1 Alternator 4 Battery

2 Alternator 3 Battery

If your concerned about your batteries becoming overly discharged, we recommend consider installing a battery protector.

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