True® Large 12v Dual Battery Kit

(21 customer reviews)

$130.95$150.95

Best dual battery setup kit with voltage-sensitive relay (VSR) for adding that 2nd or 3rd battery to the system in your car, truck, van, SUV, RVs, boat, or whatever you wish.

  • Heavy-duty & guaranteed no volt drop
  • Compact, durable and smarter
  • Free Shipping or visit return and terms policies
SKU: DBK12LARGE Categories: ,

Description

12V Dual battery wiring kit contents

  •  1 (SBI) Smart Battery Isolator install kit with mounting screws
  •  20 feet #6 high flex red cable with tinned copper cable lugs
  •  3 feet #6 high flex black cable with tinned copper cable lugs
  •  2 positive brass alloy battery terminal ends
  •  1 negative brass alloy battery terminal end
  •  3 loose crimp-on tinned copper cable lugs
  •  2 sections of adhesive lined shrink tube
  •  5 zip ties
  •  1 – 2nd battery kit installation booklet
  • 12v dual battery wiring kit diagram included
  • Official retailer of True® dual battery relay kit
  • Delivery: USPS first class or priority mail

A TRUE exclusive!

best dual battery kit 2022

Product Features

  • Best dual battery install kit for boats, cars, 4WD, trucks, Caravan, RVs, or  general automotive & marine application
  • 140 Amp Voltage Sensitive Relay
  • Priority charging for starting battery
  • Alternator outputs up to 150 amps
  • The True® dual battery charging kit is a fully automatic battery management
  • Easy to install DIY 12V dual battery wiring kit  for trucks and boat with wiring diagram
  • Waterproof, shockproof, casing, and heat resistant cables up to 130 degrees for safe and efficient use of the auxiliary battery system.

The 12v dual battery system kit utilizes the simplest and most advanced technology to keep all your batteries charged using the engine’s electrical system but isolating the starting battery so you never get stranded.

The True® dual battery install kit uses the same voltage-sensitive relay we have installed in our boat and camper to keep the secondary batteries charged but isolating the starter battery system so it stays charged. The great thing about these is that you don’t have to reroute any alternator wires and they switch charging automatically.

The best dual battery system kit allows a safe charging and separation of starting and auxiliary batteries in all types of boats, RVs, 4WD, camper, truck, caravan, and even solar applications. When the engine is started, starting and auxiliary batteries are separated allowing only the starting battery to be charged. When the charge voltage reaches 13.3 volts the voltage-sensitive relay engages allowing both the starting and auxiliary batteries to be charged.

This is indicated by the light in the top LH corner being illuminated.

When the engine is stopped and the battery voltage falls below 12.8 volts the (VSR) Voltage-sensitive relay disengages separating the start and auxiliary batteries, at this point, the indicator light will be out and the True® best dual battery cable kit continues to power any accessories without risk of draining the starting battery.

True® Smart Battery Isolator Kit sensing features

The (VSR) voltage-sensitive relay also has dual sensing technology which detects the charge of both batteries. If either battery is receiving a charge, e.g. a battery charger is connected to the secondary battery; the VSR will engage and charge both batteries. True®  technology is known for 12v dual battery system kit  heavy-duty performance.

The True® 12v dual battery cable kit is easy to install and comes with all components and instructions required to complete the install. There is no need to cut into any factory wiring that may void your vehicle’s manufacturer’s warranty.

Using a True® dual battery kit for trucks and boats, vehicle owners can ensure a more efficient and reliable power distribution system for their vehicles.

CUSTOMER REVIEWS, PHOTOS AND VIDEOS

(These videos are not represented as an “Official Installation video” by True Amalgamated and True Amalgamated accepts no responsibility for its content. It is produced by our expert followers as stated. Follow entirely at your own risk.)

 

 


Reviews from our Amazon store..

Dual battery setup kit installation for Camper Van

 

 

 

Dual battery relay kit for truck and boat

2021 Silverado heavy-duty dual battery system kit installation

 

The True® dual battery install kits are popular among off-road enthusiasts, campers, overlanders, and other individuals who need reliable power for extended trips or heavy use of electrical accessories.

 

2019 GM Truck  dual battery setup kit from custom youtube video

True® heavy-duty second battery kit installed in RV

 

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Additional information

Location

US, CANADA, AUSTRALIA

21 reviews for True® Large 12v Dual Battery Kit

  1. Jorge V. | Lakeworth, FL

    Just had my son install your dual battery kit and 2 additional isolators to connect all of my additional batteries to the main engine’s charging system. I now have 5 batteries all automatically connected to the charging source from the two engines. The single dual battery kit provided us with enough cable to make all connections we just had to purchase a couple more cable ends. He figured it would take the entire day but he was done by noon so of course we had to go fishing to try it out. We ran two hours offshore then ran all the electronics as well as the appliances including the TV.

    My son kept monitoring the dual battery isolators & checking the charge in each battery. When we finished fishing the charge in the accessory batteries had dropped to 12.1volts. The main batteries were at 12.8volts.

    We ran into shore and again checked all batteries and all five registered 12.9 volts with the engines off. While running the engines and all isolators showing indicator lights the voltage at each battery registered 13.4volts. Seems it was a big success and I no longer have to remember to turn the manual battery switches. Next week we will be staying offshore for two nights we’ll really have the opportunity to test them.

  2. Doug Z. | College Park, GA

    Just installed your boat dual battery cable kit in my pontoon boat to allow my second battery to charge when I’m running the main engine. Works great and had plenty of cables to reach the forward location of the second battery. Also discovered that my shore charger, which is connected to my second battery only, will now keep the main battery charged when I plug it in at home. Best dual battery install kit at a reasonable price.

  3. GVGrowler

    I got this not really knowing if the product was what I needed or not. I am happy to say it was perfect for my needs. The instructions are the best I have ever seen for almost any product. Very easy to understand and the testing to make sure it was installed correctly was a real help. So far this is working exactly as it should and there have been no issues at all. I look forward to using this for a long long time!

    Reviewed in the United States

  4. Ericofcourse

    Here is my review

    online customer

  5. Ray R. Kawal

    Here is the review of Ray R. Kawal

    Chevy Battery Isolator

  6. Robert

    This was easy to install and seems to be working great on my fishing boat. I added a second battery for everything besides the engine and I haven’t had a problem listening to music with the motor off since. Before adding this I had to use my jump box 3 times.

  7. Ulrich Urfer

    My Camper review

    Camper Review

  8. Jeff Ingalls

    This thing has been working like a champ. Not a single issue with this auxiliary car battery kit. Been about 5 months or so. I’m thinking of buying another one as a backup.

  9. Greg Garner

    Excellent customer service

    Excellent

  10. Bret

    This dual battery cable kit is perfect so far
    perfect

  11. LINDA D FISHER

    Works perfectly

    One thing to note: if you are going to charge your secondary battery with an ordinary charger or solar, understand that this device will turn on so that you will be charging your car battery as well. This is what it was designed to do. It connects/disconnects regardless of where the charge is coming from. You should install a manual override switch for safety and control charging.

  12. NormB

    I used this auxiliary truck battery kit, voltage sensing relay in my solar system install on my utility trailer.

  13. Vimby Shaun

    This is an easy fix for an issue that many of us RVers have.
    It’s not simple to add an alternator. This straightforward solution protects my starter battery from being drained by the auxiliary battery that powers my music and other accessories.
    Also, it serves as the battery for my RV when we are on the road. I had purchased a vintage isolater that needed twice as many connections. Much more had to be tied to the alternator.
    This is a vast improvement.

  14. WDT3

    Bench Testing Results: It’s Accurate…

    During the test, I found out that this dual battery isolator kit set points for the voltage relay were within 0.02 V of the nameplate (13.4 close & 12.9 open). The relay current energized was 0.3 A. De-energized current was 0.003 A (3 ma). It senses voltage from both sides, so charging could come from either vehicle alternator to trailer battery, or from trailer converter (shore power) to vehicle battery.

    Reviewed in the United States

  15. Smith R

    For the most part, this was a simple second battery kit installation. When the isolator is operating or performing its job, it glows blue. One topic I looked up on the internet was why the blue light on the machine stays on for so long after you switch it off. It turns out that this is typical and that it occurs frequently when a new fully charged battery is used.

    It works fine; however, longer Red wires are required. I also like the fact that all of the cables had their ends already attached. The ground wire is also a nice length and already has a ring connected. Because of the cable length, I awarded it four stars. However, it is a good product.

  16. Aldrin Tucker

    This was an easy product to install. I also watched a good YouTube video before I started. After I hooked it up and turned on my rv the light didn’t cut on until it was at 13 volts.

  17. David Martinez

    This was purchased for my 4th generation Toyota 4runner.
    This dual batter relay kit is important to my design. For my AuX battery, I utilized 1/4″ eye bolts and a Factory battery hood down kit. During the initial installation, I discovered that the relay did not function. If this occurs, swap the battery leads on the relay. My back label was incorrect. Make sure your ground line is securely connected to the relay. It works wonderfully, and I couldn’t be happier.

  18. Daniel Mayeshiba

    In my 185 bowrider sea ray, it’s been installed. in less than two hours. I’ve had it installed for about three months and it appears to be working perfectly. Sit on the sand bar for hours on end without worrying about whether or not my boat will start.

  19. Robert Loucks

    It includes everything you need to complete the installation of the dual battery isolator kit. The most difficult element is determining the optimal wiring method.

  20. Carl Thomas

    I needed a new battery and wanted to add two batteries, so I purchased this item. I acquired two identical batteries and placed them in a 2009 Silverado. There is enough wire and other pieces to complete a two-battery installation. It took roughly two hours to complete. The device appealed to me since the two main lugs did not need to be linked to specialized cables. The device recognizes which battery is which automatically. This aids in identifying the cable holes on the isolator’s side.
    The only thing I would change is to use slightly bigger drilling for the sheet metal screws. I called customer support with a single inquiry and was pleased with the promptness and response. This unit is superior to the others in every way.

  21. Bruce Johnson

    A customer was baffled by what the blue light accomplishes. When the batteries are linked and charged together, it turns on. It shuts down when one of the batteries dips below 12.7 volts, at which point the batteries are disconnected. Another reviewer complained that the temperature range of 105 degrees was too low….the 105 degrees are centigrade, or considerably beyond the boiling point of water. I was apprehensive that the clear plastic cover would be too fragile, but once screwed into place, it appears to be rather sturdy. I did use strain relief on the two wires that enter the device to prevent them from placing any strain on the lugs in the gadget’s base.

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