Best Dual Battery Isolator

Buying Guide to the Best Dual Battery Isolator

Installing a dual battery in your van maybe one of the best ideas you may want to look out for. Regarding the benefits that come with it; from powering portable refrigerators, installing additional lighting and sockets to power up your mobile charger, the benefits cannot be less.

Upon installing additional appliances that consume power, a normal battery will drain the power so fast especially if the vehicle is not moving to leave you stranded in the middle of nowhere when it fails to start up. However, with the introduction of a dual battery, such problems are solved.

What Are Dual Battery Isolators And How Do They Function?

As the name suggests, isolators function by isolating the primary battery which is used to start the vehicle leaving it to maintain its charge when the engine is not running. If your RV has additional appliances such as portable refrigerators or additional lighting bulbs, which uses the vehicle’s battery power, the moment the engine stops running, the isolator will cut off the primary battery used to start the engine so that the appliances don’t drain both batteries.

When a vehicle’s engine is started, there is a surge of power to the starter which triggers the alternator making it start producing power. The isolator responds by providing power to the primary battery until it is charged fully. Upon the primary battering reaching its maximum, the current is switched to the auxiliary battery. The current that is used to power up the appliances is derived from the auxiliary battery.

Manual Vs Automatic Battery Isolators

Manual switches can also be used in isolating the batteries. Both will serve the same purpose of providing current to the primary battery until it is fully charged then switches the current to charge the auxiliary battery which powers the appliances in your RV.

A manual switch requires human intervention. This poses a challenge since humans forget easily and in an instance where the isolator is not turned on draining all power in the primary battery, the vehicle will stall. Automatic isolators will links the batteries for charging and isolate them while discharging, very smart, right? An isolator with surge protection is recommendable as it protects the vehicles onboard computer.

Top Batteries for The Dual-Battery System

Batteries come in two main forms, either shallow cycle (single high-current discharge) or deep-cycle battery. Shallow cycle batteries are mainly found in vehicles from the manufacturer.  They provide a high amp charge which is able to start the engine.

Deep-cycle batteries provide sustained power over long periods of time hence preferred as an auxiliary battery for a dual battery system. The deep-cycle battery is larger in size and more expensive as compared to their counterpart shallow-cycle battery.

The dual-battery system varies in size and weight. Variation in the internal lead plates in terms of numbers ad thickness brings out the overall difference. The internal lead plate and their thickness define the amp-hour capacity of the battery. For a better dual-battery, choose one with more lead plates and whose terminals are dual fit.

Shallow-cycle batteries have thinner plates and take less time to charge to full as compared to deep-cycle batteries which have thicker plates and takes more time to charge to full. In a dual-battery system, it is necessary to put into consideration if the battery isolator is capable of charging both batteries.

While on a mission to purchase a dual-battery system, it is necessary to put into consideration the type and formation of the batteries.

Which Are the Best Types Of Isolators

There exist numerous isolators in the market but this article shortlists the best and highly regarded.

Diode Isolators

The battery circuits in this type are isolated from each other. Each battery is an independent power source since the current flow is isolated. The circuits act as a one-way valve between batteries.

Solenoid Isolators

This type charges the batteries in a parallel manner. When the ignition of the van is turned on, the solenoid isolator switches on allowing the current to flow in both batteries. When the primary battery is full, the isolator solely diverts all the current to the auxiliary battery. For parallel charging dual-battery, it is recommended the batteries be uniform; of the same age, capacity, size, and of the same design. When the ignition is turned off, the isolator’s switch automatically isolating the primary battery and the auxiliary battery is left for consumption.

Electronic Isolators

In the dual battery system, electronic isolators are regarded as the best. The batteries are not a must be identical and of the same properties, the electronic isolators are modified I manner to recognize and identify the difference in the batteries adjusting the charge rate. However, the primary battery is obviously given priority allowing it to charge while the engine is running and isolating it when the engine is off.

On the basis of vehicle usage, it is best to choose the right system. For RVs, the van will mostly be on-road hence the system should not be of concern on dust and water resistance features. For off-road vehicles, the best system is one with water and dust resistance features.

Smart Solenoids

This type of isolator is essentially a smarter version of solenoid isolators. They possess voltage sensors that allow automatic operation. They are smart enough to hold voltage to the auxiliary battery until the primary battery reaches a predetermined voltage then charging commences to the auxiliary battery. Charging proceeds parallel for the dual battery.

When the ignition is turned off, the smart solenoid sensor turns on. Draining of the primary battery will reach a predetermined voltage then the sensor will isolate it leaving the auxiliary battery to be used by the electrical appliances. The sensors function in such a manner to avoid draining all power and flattening of the starting battery.

Voltage Sensing Relays Isolators

They function like smart solenoid isolators. However, the charging of the dual battery is not parallel. In addition, it uses a relay and not a sensor with the two batteries electrically separated. In an instance when the main battery drains below a predetermined level, the auxiliary battery is disconnected from charging to charge the primary battery to its predetermined level.