East Coast Customs
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Dual Battery Systems

A dual battery system in a 4×4 is very handy, especially if you like running accessories from your 4×4 when camping and in particular if you run a compressor fridge in the back. The idea of a dual battery system is to have all (or most) of your accessories connected to the second battery (usually a deep cycle). As your accessories use power from the second battery the isolator prevents power from draining from your main starting battery leaving it ready for you to start your vehicle when needed. When you start your vehicle the isolator senses the charge from your alternator and links the 2 batteries together and charges them as you drive

There are a few ways the second battery can be wired into the vehicle, depending on its intended use and the system flexibility required. But no matter what, the second battery must be installed and wired – in the engine bay, the passenger compartment or load area – so that it can be isolated and doesn’t flatten the vehicle’s starter battery.

To try simply and quite complicated topic, there are generally two types of dual battery / charging management systems. The first, older type uses some form of switching relay to isolate and switch between batteries via either a manual switch, or some pre-determined voltage threshold. The second, more modern version, being a DC to DC battery charger.



The new Ironman 4×4 DC to DC 40amp boost, 3 stage battery charger. With the new generation of vehicles it is important to ensure that auxilary battery charging is managed in a way to maximize the charge. The Ironman 4×4 DC to DC 40 amps chargers uses the latest generation technology producing more power in a much smaller compact unit. The DC to DC charger is able to cope with under bonnet heat, vibration and has a unique heat sink to maximize cooling and maximize efficiencies. This DC to DC charger is encapsulated in a weatherproof polymer.

The Ironman 4×4 DC to DC charger has a remote dash mounted LED to indicate charge status. A fantastic feature is the  selectable battery selection with the ability to charge all types of batteries, including FLOODED, AGM, GEL and Lithium. This  charger is designed to manage and maximize the charge to your batteries.

Using the boost technology the DC to DC charger boosts the voltage to ensure the batteries are maintained at 100%, making it better for battery life. The boost technology automatically senses for all low voltage alternators, camper trailers, long cable that may incur voltage drops and batteries requiring a high charge.


  • 3-stage 12V Booster Charger
  • 40A max output
  • Selectable output voltages
  • Over current and temp protected
  • Precise under voltage protection (No external isolator required)
  • High efficiency (Typical >96%)
  • Remote charge status LED indicator
  • Very low standby current <3mA
  • Optional start assist and boost charge features increase amperage output to 80A max



The Ironman 140 Amp Dual Battery Kit allows two batteries to be charged at the same time. When the engine is started and the main battery reaches 13.4 volts, the Ironman module engages, allowing the two batteries to be charged simultaneously.

The Ironman dual battery monitor displays the voltage levels of both batteries. The Ironman 140 Amp Dual Battery Kit eliminates the possibility of draining the starting battery, as long as your accessories are connected to your auxiliary battery.When the voltage drops below 12.8 volts (e.g. the engine is stopped), the Ironman module disengages, isolating the batteries.


  • Dual sensing
  • Automatic function
  • Cut in when main battery above 13.4V
  • Isolates main battery below 12.8V
  • Ignition protection
  • All hardware included
  • Monitor dims with headlights on
  • Fully sealed
  • Easy to install



A dual battery manager is a must-have addition for any 4 wheel driver who loves the great outdoors and wishes to camp in comfort with good lights, a fridge, music and any number of accessories running on a dual battery system.

The Ironman 275 Amp Dual Battery monitor allows two batteries to be charged at the same time, once the main battery reaches 13.4 volts. This ensures that your cranking battery is always at full capacity. It is supplied with a dual battery monitor which displays the voltage levels of both batteries. This dual battery manager allow you to run accessories from a second battery to save your starting/cranking battery.

Emergency Parallel Function: 

The Ironman 275 Amp Dual Battery manager allows the user to override the automatic function and link the two batteries together. This can be done by turning the yellow knob on the unit or by pushing the override switch located in the vehicle.


  • High Amperage capacity
  • Dual sensing
  • Automatic function
  • Cut in when main battery above 13.7V
  • Isolates main battery below 12.2V
  • Dual manual override
  • Additional override switch
  • Ignition protection
  • Monitor dims with headlights on
  • Easy to install



The Ironman dual battery monitor displays the voltage levels of both batteries.



This start assist kit allows you to start your vehicle off the auxiliary battery in a situation where the main battery is flat (e.g. headlights were left on).

When combined with our 40A DC to DC battery charger, the maximum output increases up to 80amps, doubling the total amperage.


  • Automatic emergency vehicle  start.
  • Boosts DC to DC  charger output to 80amps
  • Start Assist –  The Start Assist Booster  Kit when used in conjunction  with the Ironman  4×4 IDCDC40, is an  automatic emergency  override function allowing  the vehicle to start utilising  the auxiliary  battery in situations where  the main battery is flat.
  • Boost Charge –  This kit will also double  the 40amp output  of the Ironman 4×4  IDCDC40.  Allowing up to 80amps for  the initial fast charge of the  auxiliary battery.



Due to the custom and unique nature of 4×4 vehicles and different requirements for dual battery setups, there is no “one price fits all” guide, so please call us today for a quote for your vehicle.

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Michael Sanderson said this about East Coast Customs...

"Hi All, (Apologies to all on the long winded testimonial, very hard to put it all into a short spiel) I was introduced to East Coast Customs through a friend of the family who just had his HSV Senator cammed, at the time I was looking for a reputable company to Cam my wife’s 6.2L HSV Clubby and Supercharge my 6.2L HSV GTS. I had been looking around for a while and was given various options and prices to do the work required. I approached East Coast for their advise. Rob spoke to me at length as to options available, I’m not a mechanic so a lot of what Rob initially said went over my head so Rob dumbed it down so I understood. From the moment I made a commitment to have the cars done I have been unbelievably impressed with the service and quality of work provided by East Coast, my car was fitted with the new design Yella Terra 2.9L Blower, Stage 4 cam pack, Twin Plate clutch, Rip Shifter and a variety of other bits and pieces to pull it all together and my wife had a stage 4 Cam pack fitted, the Blower was a headache from the start as far as getting one, Yella Terra to their credit would not release their new model until it was right. Matty kept me informed all the way through the procurement process until he had a confirmed commitment the blower was on the way. As I work close to East Coast I dropped in the first day just to get an update, I was standing at the roller door looking in when Matty said come in we will show you what we are doing, I was somewhat hesitant as most mechanics don’t like you looking over their shoulder. This was the first time I met Ben, Ben is not only part owner he is also the head mechanic (what more could you ask for owners being Mechanics and Dino tuners). Ben talked me through what he is doing and the reasons he was doing it, I learnt more about the dynamics of an engine in one week than I have picked up over my life time. I called in average twice a day to just have a look to see how things were progressing and Rob, Ben, Matty and the team were always pleasant and informative of what they were up to, as this was the first fit up of the new Yella Terra Blower to a HSV there were a few minor issues that Ben needed to overcome, which he did with great results. I can’t stress enough the quality workmanship and service I received from East Coast, as an example, East coast had to remove my exhaust system to replace the clutch, they notice a poor weld job where I had had a hot dog removed from my hurricane exhaust system by a reputable exhaust company (Wasn’t completely welded, they used exhaust silicone to fill up the join) Ben advised they would weld it up before refit. When I returned on another visit the exhaust was in but they were cutting these sections out, I enquired why and Dan advised their weld look terrible as the silicone jammed in the join was causing the weld to splatter, when I spoke to Rob he advised it looked unprofessional and they are replacing both sections with new 3 inch pipe about a metre long each at no charge, they could have just welded the old pipe up and I would have been none the wiser, this is just one of the areas there quality of work and service stands out as a number of them come to light through the week. As they say ‘when you are on a good thing stick to it’ I already have my sons SS booked in next week for an OTR and maffless tune. All I can say is give them a go, you won’t be disappointed. I end here with this one parting comment, tell East Coast what you want and listen to their suggestion, I did and can’t be happier with the results. My wife’s and my car went in with an average of 380hp at the wheels, my wife’s left with a respectable 433hp at the wheels (already had an OTR), mine left with 580hp at the wheels, mine has a lot more to go but we capped it at 580 to protect the standard bottom end and heads. To Rob, Ben , Matty and the boys, with the quality of work and service you provide your business will go far, and congratulations in your new relationship with UPREV Engine Management Solutions in the United States, for UPREV to get on board and East Coast the only Protuner on the East Coast is impressive...."

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