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NVX BIR80

80-Amp High Current Dual Battery Isolator and Relay for Car Audio Systems (Handles up to 150-Amp Surge)

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• 80-Amp continuous / 150-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16.5V DC operating range

Learn more about the bir80
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Universal – fits most vehicles.

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2026-07-27 11:08:20
List price $19.99
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Product Highlights


• 80-Amp continuous / 150-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16.5V DC operating range

Description


NVX brand icon

Authorized dealer

Isolate with Confidence

The NXV BIR80 Isolator is the perfect solution when adding a secondary battery to your audio system. It allows the second battery to be fully dedicated to the sound system and does not create a voltage drop like common isolators tend to do. The isolator will draw less than 1-Amp when your vehicle is powered on. All of this will ensure that your battery will be isolated with confidence!

Lengthen the Life your Batteries

When two vehicle batteries are wired in parallel they have a tendency to charge and drain one another. Installing a relay that disconnects the batteries when the engine is off prevents excessive wear and lengthens the life of the batteries. Whenever you turn your engine back on, the batteries will be connected without any voltage drop to the second battery.

Product Details:

  • Used to isolate a second battery powering audio, video, navigation, or other equipment
  • Prevents a dead starting battery after listening to the stereo with the engine off
  • Capable of handling 80-Amp continuous and 150-Amp surge
  • The relay coil will operate safely between 10 and 16.5 Volts
  • Can be used to completely isolate equipment from power when the ignition is off
  • Dimensions: 2-7/8" W x 1-3/8" D x 3" H
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Frequently Asked Questions (FAQ)


Connect one large stud to your Starting Battery and the other to your Auxiliary Battery. Connect the small Ground terminal to the chassis. This allows both batteries to charge while the engine is running.
Tap the small Positive (+) terminal to a "Switched" 12V source (like a cigarette lighter or ignition fuse). This ensures the batteries only connect when the car is ON, preventing your amp from draining your starter battery
Some heat is normal during heavy charging, but "scorching" heat means a loose connection. Ensure your Ring Terminals are crimped tightly and the nuts are torqued down. Loose wires create resistance, which generates heat.
No. This unit is rated for 80 Amps constant, but a starter motor pulls 200A+. Using it to jump-start will blow the internal contacts. It is designed for charging and isolating, not for high-current cranking.
The "Click" means the relay is moving, but the power isn't flowing. Use a multimeter to check for 12V on both large studs while the engine is running. If one side is dead, check your fuses or the main battery cables.

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Specifications & Details


Battery Isolator Features
Compatible Amperage
80 amps
Surge Amperage
150 amps
Width
1-3/8"
Height
3"
Depth
1-3/8"
Isolator Type
Relay (Solenoid)
Warranty and Return Policy
Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Item Details


Manufacturer:

NVX

Model Number:

BIR80

Weight:

0.63lbs

Internal SKU:

bir80

Internal Product ID:

46581

Product and How-to Videos


Customer Ratings & Reviews


NVX BIR80 thumbnail image

5 star
100%
4 star
0%
3 star
0%
2 star
0%
1 star
0%



Durability
5
Value
4.8
Features
4.8
Design
4.8
Usability
4.8

Customer Reviews

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Excellent product but carrier for delivery should be changed

Excellent and performing as expected. However, usage of USPS instead of UPS to ship from US to Canada would save a lot to the Customer. Beside Canadian taxes and Customs fee, UPS charged to me as much as what it cost me for the product is not acceptable.

By Yves on September 17, 2013

71 found this helpful


Great product!

I got it from Sonic three weeks ago and had it installed in my car by pros. I'm using it to isolate one Shuriken BT-20 that is powering my music. I started using it with one amplifier configuration. Now I have two amplifiers. I'm listening to music for about 2 hours with the engine off at loud volume and I haven't had a battery discharged yet. I don't recommend using the system with the engine off for extended periods but for the purpose of running a test it'll be fine. The isolator is working. It's pretty small, so it fits almost anywhere. For this application, with one secondary battery powering two amplifiers, it gets the job done. And that's enough for me. If your building a system like mine, then you got to purchase this isolator.

By Ronald on July 25, 2013

71 found this helpful


Survives!!

I've had this under my hood during the winter (temps of -20 without windchill) and it keeps working. Easy to use, and small enough to find into a tight engine bay. Just make sure you don't over draw it.

By John on March 5, 2014

66 found this helpful


Does what it is supposed to

This item works great to protect your starting battery while playing music with the engine off. I even purposely tested to make sure only the battery hooked to the amps drained down after an extended time of use. No complaints on any NVX product.

By Alex on August 10, 2015

62 found this helpful


Works as rated

I bench tested this on load and it holds up perfectly in spec. Would buy again nvx is a very under rated brand and good quality.

By Anthony on August 16, 2015 Checkmark Icon Verified purchase

56 found this helpful


NVX BIR80

Although designed for car audio, I purchased this for my Fishing Pontoon boat, I wanted to keep the battery for my trolling motor isolated from the primary battery so I wouldn't get stranded on the lake not being able to start the engine due to draining the primary while also keeping both batteries charged by the alternator while the engine is running. Simple easy to follow instructions, great quality product, and the price is 1/10 what you'd pay for marine-specific isolator that does the exact same job!

By Mike on March 20, 2020 Checkmark Icon Verified purchase

49 found this helpful


Needed very badly

What a great product, NVX has great products. I have one amp on a toggle switch because the remote switch in the amp is stuck in the on position and sometimes I forget to turn the amp off went I park my car over night and my batteries go dead. I installed this product now my problem is over, I never have to jump start my car again and it was so easy to install. Thank You Sonic Electronic and thank you NVX for making such great products

By Louis on April 19, 2017

49 found this helpful


Awesome relay

Have used these several times on various installs and different wiring setups, never disappointed.

By Richard on March 30, 2017

49 found this helpful


great value

I recommend this product if you're looking to isolate two batteries from each other. very easy to install you can almost install this anywhere underneath your hood or in your trunk It's relatively small and it does the job very well on isolating the battery.

By Luis on May 14, 2020 Checkmark Icon Verified purchase

44 found this helpful


price was right for feature set

I need one of these. I dont know much about these so its a good place to start and not too expensive if I change my system further on. Will update... seems well made so far. nice and heavy,,,,,,,....

By 5ob3rDennis on June 27, 2025 Checkmark Icon Verified purchase

1 found this helpful



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Modern vehicles often require specific brackets, wiring harnesses, and mounting solutions. A fit guide ensures:

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Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.