Garage
Shop

NVX BIR500

500-Amp High Current Dual Battery Isolator and Relay for Car Audio Systems (Handles up to 700-Amp Surge)

NVX
Shop all NVX
Limited time!
Product videos
highlight-star-icon

• 500-Amp continuous / 700-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16V DC operating range

Learn more about the bir500
Light bulb Icon

Discover more. Set your vehicle.

2026-07-27 11:08:20
List price $95.99
Thanks , You Pay:
-17%

$79.99

 with warranty
Starting at $14/mo or 4 payments of $20 Buy now, pay later and installment payment plans are offered by Afterpay and Affirm. Learn more

Heads up

We confirm fitment and offer accessories for speakers. Please set your vehicle first if you would like to purchase more than one bir500.

Set your vehicle or Return to product page
Purchase $400 or More of NVX and Save 15%!
shipping truck icon Free shipping in USA. Provide zip for delivery date.
Dollar Icon
VIP Product Get $8.00 in rewards to spend later
Quantity
In Stock
Brand new

Buy it now


Acima Logo

No Credit Option

Flexible Lease Payments

Early Purchase Options

Quick Approval Decision

Extend logo

Keep your product protected longer! Extend the warranty after the manufacturer warranty expires. 

  • Hassle-free immediate replacement within minutes!
  • Easy online claims 24/7
  • Covers product breakdowns and failures
Swoosh Icon Icon of Swoosh

For over 25 years, we've been your X-Factor – the team dedicated to having the biggest impact on your shopping experience!

Award winning icon
Award-Winning Service
Shipping icon
FREE Shipping Orders $49+
60 days return policy icon
60-Day Easy Returns
lowest price guarantee icon
Guaranteed Lowest Price
inHouseExpert
In-House Experts
NVX - Worth the Envy - Direct to Consumer Car Audio

Product Highlights


• 500-Amp continuous / 700-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16V DC operating range

Description


NVX brand icon

Authorized dealer

Isolate with Confidence

The NXV BIR500 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 500-Amp continuous and 700-Amp surge
  • The relay coil will operate safely between 10 and 16 Volts
  • Can be used to completely isolate equipment from power when the ignition is off
  • Dimensions: 2-3/8" W x 2-3/8" D x 3-3/4" H
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Frequently Asked Questions (FAQ)


If you have a high-output alternator (250A+) or multiple large amplifiers, you need the BIR500. Its 500A rating prevents the internal contacts from welding together under the massive current draw of a competition-level system.
No. The BIR500 is a "Normally Open" relay. When your ignition is off, the circuit is physically broken. It draws zero current in standby, ensuring your batteries stay isolated and your starter battery remains fully charged.
To take advantage of the 500A capacity, you must use 1/0 AWG or larger high-quality copper cable. Using thin wire will create a bottleneck, causing the wire to overheat and significantly dropping the voltage to your rear batteries.
Yes. The BIR500 is perfect for winches, which can pull massive current. By using this isolator, you ensure the winch only pulls from the auxiliary battery (or both when the engine is running) without risking a dead battery in the woods.
Not at all. Because the BIR500 uses heavy-duty industrial internal contacts to move 500 Amps, a loud mechanical "click" or "thunk" is a sign of a strong, healthy connection. It means the relay is fully seated and ready for high current.
Unlikely. If a channel pops with no music, bypass the isolator and connect the amp directly to the battery. If it still pops, the amp is defective. If it stops, check the isolator for a loose ground or a failing internal contact.

Best selling similar products

SGP35 small

Stinger SGP35

• Prevents Primary Battery Discharge
• Maximum Current Transfer
• Ideal for 2nd Audio Battery Isolation from Vehicle Systems
• 500A Constant/ 900A Peak

(1)

$117.99

List price $379.00

LL-IR500A small

Limitless Lithium LL-IR500A

• 500-amp Relay and Battery Isolator
• High current isolation relay designed for adding a secondary battery
• Prevents primary battery discharge when the vehicle engine is off
• Maximum Contact Rating: 500 amps
• Mechanical Life Cycle: 100000

$79.00

List price $79.00

XSBI200 small

NVX XSBI200

• 200-Amp continuous / 300-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16.5V DC operating range

(6)

$49.99

List price $79.99

BIR200 small

NVX BIR200

• 200-Amp continuous / 300-Amp surge
• Ideal for car stereo systems and mobile electronics
• Prevents the main starter battery from draining
• 10V to 16V DC operating range

(17)

$49.99

List price $59.99

IB500 small

The Install Bay IB500

• Battery Isolator and Relay
• 500 Amp
• Prevents Primary Battery Discharge
• Maximizes the Current Transfer
• Extends Battery Life
• Universal 12V Applications

(39)

$133.99

List price $148.99

SGP32 small

Stinger SGP32

• 200 amp Battery Isolator and Relay
• Prevents primary battery discharge
• Maximum current transfer
• Extends battery life
• Universal 12V Applications

(8)

$108.99

List price $229.00

BIR80 small

NVX BIR80

• 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

(10)

$15.99

List price $19.99

SGP38 small

Stinger SGP38

• 80 amp Battery Isolator and Relay
• Prevents Primary Battery Discharge
• Maximum Current Transfer
• Universal 12V Applications
• Extends Battery Life
• Water Resistant Black Phenolic Plastic
• 100,000 Mechanical Cycle Life

(5)

$31.99

List price $69.00

IB200 small

The Install Bay IB200

• Battery Isolator and Relay
• 200 Amp
• Prevents Primary Battery Discharge
• Maximizes the Current Transfer
• Extends Battery Life
• Universal 12V Applications

(14)

$113.99

List price $126.99

Specifications & Details


Battery Isolator Features
Compatible Amperage
500 amps
Surge Amperage
700 amps
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:

BIR500

Weight:

2.00lbs

Internal SKU:

bir500

Internal Product ID:

46583

Product and How-to Videos


Customer Ratings & Reviews


NVX BIR500 thumbnail image

5 star
86%
4 star
11%
3 star
0%
2 star
3%
1 star
0%



Durability
4.8
Value
4.9
Features
4.8
Design
4.8
Usability
4.9

Customer Photos & Videos


Customer Reviews

Sort by:

Loading...

Excellent product

Works as advertised. Easy to install. No problems so far.

By Imran on May 8, 2014

115 found this helpful


Unbeatable deal

Great product at a great price. Shipping is reasonable and fast.

By sonrich64 on March 17, 2014

111 found this helpful


very good

you wont find a cheaper battery isolator that handles 500 amp

great product thanks sonic

By Abdulrahman on February 2, 2014

99 found this helpful


does what its supposed to

Very nice quality piece. Gets the job done. Very simple to install. Don't overtighten the lock Nuts though.

By Z on May 8, 2014

102 found this helpful


worth the money

Im totally satisfied with my purchase. This is a good and durable product. Like always, sonic electronix processed and shipped my order fast.

By thomas on May 5, 2014

100 found this helpful


Very happy.

Product works just as advertised and suits my purposes perfectly. My second battery drives a heavy duty wench, fog lights, and stereo system and the NVX BIR500 has been keeping it well charged. It was easy and quick to install. The only thing I wish it came with would be rubber caps for the posts. I accidentally tapped them more than once, causing sparks (that's why the 3 under 'look/design'), Before I wrapped them in electrical tape. Other than that I've very happy with it.

By Jon on July 13, 2014

100 found this helpful


Great equipment for the price

Had my profesional installler put in in line between my batteries (which are in parallel), works like it should with no probloms. Can't beat the price for a 500 amp isolator!

By Cool Tuff on October 27, 2014

93 found this helpful


Nvx bir500

This prod is to keep your batteries sepret from one to the other is the best way to keep your batteries all way charge and sepret at same time verry good prod

By Flaco sound on September 17, 2013

88 found this helpful


Perfect for use with After Market Sound System Battery Power

Met my expectations.Perfect use for allowing the Second Battery to work with my Aftermarket Sound System without draining my Primary Battery.

By Bob on March 1, 2015

72 found this helpful


good buy

Exactly as described. Easy to install. Havent gotten the whole system up and running yet so we dont know if it works yet or does its job.

By Cody on June 19, 2015 Checkmark Icon Verified purchase

66 found this helpful



SGP35 main

Stinger SGP35

• Prevents Primary Battery Discharge
• Maximum Current Transfer
• Ideal for 2nd Audio Battery Isolation from Vehicle Systems
• 500A Constant/ 900A Peak

(1)

$117.99

List price $379.00

Related Searches


Save up to 10 different vehicles in your garage

Add vehicle
Loading...
Identify your vehicle and submodel details
  • Owner's manual
  • Vehicle's insurance card
  • Vehicle registration
  • Vehicle produced after 2005: Inside driver's side door
  • Vehicle produced before 2005: Rear passenger doorjamb, glove box, center console, or engine compartment
Car Info Side Door Icon
Vehicle Registration Icon
Vehicle Insurance Icon

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

  • You see only parts engineered for your exact vehicle
  • You avoid incompatible radios, speakers, or wiring
  • Installation is smoother, faster, and frustration-free
  • You get the correct accessories the first time

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