Battery Isolators

Battery Isolator

Battery Isolators are ideal for dual battery systems commonly found in recreational vehicles, boats, large trucks or motor homes. The isolator solves two problems:

  1. it recharges both batteries (or battery banks) by splitting the charge current into multiple branches without the need to wire the batteries in parallel, and
  2. it ensures that the starter battery (or primary battery) of the vehicle remains full enough to start the engine by isolating it from the auxiliary (or secondary) battery.

Properly isolated batteries are also protected from discharge should the partnered battery fail. Usually, if a single battery in a battery bank fails, the damaged battery discharges (or worse damages) the entire lot.

Some battery isolators also have an override function which allows both batteries to be used for certain high powered appliances (e.g. a winch).

Battery isolators may also have an application in stationary solar power systems for emergency lights or pumps, refrigeration for medical supplies or similar.

Battery isolators only work with battery banks of the same voltage.


Installation of a battery isolator is fairly simple as it does not interfere with existing wiring. Connect your auxiliary loads to the auxiliary battery (don't forget suitable fuse).

Isolators with override function also require an additional switch - a momentary push button switch is recommended. The cable for the override should be fused separately.

Note: Do not connect gel-cell batteries to a vehicle's alternator.

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Voltage Sensitive Relay - Battery Isolator 12V 140A
Voltage Sensitive Relay - Battery Isolator - 12V - 140AVoltage sensitive relay (VSR) unit for 12V systems. Can be used as battery isolator for campervans or other RVs. Weatherproof IP65.[BAX-020]
4 in stock
Battery Isolator Smart Start 12V 100A (Redarc)
Battery Isolator Smart Start - Redarc - 12V 100A12 Volt 100 Amp battery isolator to separate starter and auxiliary deep cycle battery of your motor homes, campervan, boat or yacht.[BAX-110]
1 in stock
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We install solar systems in Northern NSW and Southern QLD.

Gold Coast (from Coolangatta to Southport), Nerang and Hinterland (Beaudesert) and out West (Warwick, Stanthorpe, Killarney)

Northern NSW (Tweed Heads to Yamba, including Evans Head, Byron Bay and Ballina); the Far North Coast Hinterland (Grafton via Lismore to Murwillumbah) and out West (Casino to Tenterfield, including Drake and Tabulam, as well as Woodenbong and Bonalbo)

For larger system we also go up to Brisbane or down to Coffs Harbour and even Glen Innes. Other places by arrangement.

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