PriorityStart! 12 Volt ProMax Battery Protector
Special deals available for this item; call us at 1-800-405-2121 today and save!
Item #: 12V-PROMAX   |    In Stock

PriorityStart! 12 Volt ProMax Battery Protector
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PriorityStart! 12 Volt ProMax Battery Protector

Special deals available for this item; call us at 1-800-405-2121 today and save!
Item #: 12V-PROMAX   |  In Stock

Today's Price: $104.95
Free Shipping! Free Shipping

Today's Price: $104.95

Best Value
Free Shipping
1 Year Factory Direct Warranty
Brand New
100% Compatibility

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Product Specifications for PriorityStart! 12 Volt ProMax Battery Protector

BM Part #: 12V-PROMAX
Voltage: 12 Volt
Length: 5"
Width: 3"
Height: 1.25"
Shipping Weight: 3.00Lbs
Warranty: 1 Year Factory Direct
Product Manual: Download
  • No more dead batteries!
  • Automatically Disconnects; any drain on the battery (when engine is off), even a short, leaving starting power, NO dead battery!
  • Automatically Reconnects; simply put foot on brake, or operate light switch, any small load change and start the vehicle. No button to push, or raising the hood.
  • Do-it-yourself installation 3 easy steps - No hard wiring. Easy to attach; Connect your vehicle positive cable to PriorityStart! Attach PriorityStart! Cable to your positive post. Attach the ground wire to the batteries negative post-that's it!
  • 20 years proven technology protecting vehicle battery alternators, electrical system, your family and your wallet, used by thousands of law enforcements, utilities, and fleets, many using 2way/CB radios, radar, GPS, Dual batteries, chargers, TV, monitors etc.
Free Standard Shipping

Order today and receive free standard shipping on your PriorityStart! 12 Volt ProMax Battery Protector. Only valid in the contiguous 48 states and not valid with any other offer. Physical address required (No PO Boxes).

Current models include LED light.

Easy to Attach!

  1. Connect your existing vehicle positive cable to Priority Start
  2. Attach the PriorityStart! 12v battery protector cable to your battery's positive post
  3. Attach the ground wire to the battery's negative post

This PriorityStart! battery protector is specially designed for Law Enforcement, Fleets, Utility, Emergency, and Security vehicles with multiple accessories. PriorityStart! 12v battery protector is an automatic computerized on/off “switching” system protecting battery voltage and starting power. If battery voltage drains below 11.7 volts when engine is off, it automatically disconnects the load. The battery voltage immediately recovers. TO START: just step on brake pedal, starting power is automatically reconnected. Designed to handle 1000 “starting amps”.

Often multiple accessories mimic “engine run”. The Pro-Series is specially designed to handle multiple accessory loads, utilizing higher value electrical components to monitor “engine run” when the engine is off.

Pro-Series is successfully being used in vehicles with:

  • 2 way/CB radios
  • Radar Systems
  • GPS
  • Cell phones
  • Computers
  • Flashlight Chargers
  • Mobile Equipment
  • Dual batteries
  • Hi-Amp Stereo Systems
  • Mobile T.V

PriorityStart! battery protector is an electronic cut off switch. It will not charge or maintain a battery.

Have a question regarding use of this item? Contact PriorityStart directly for installation or technical support. They can be reached at (800) 780-8276

View Parallel Dual Battery Installation Instructions

80 Reviews | 4.7 out of 5
5 stars (63)
4 stars (13)
3 stars (1)
2 stars (1)
1 star (2)
Would recommend this product.
What our Customers are saying
doesn't work on my car without special steps
October 9, 2017
by on October 9, 2017

The device was correctly installed by my mechanic. Apparently, per the Priority Start person, there are some cars where the usual instructions to trigger a small voltage change and activate the switch does not work. There is a work-around: unplug the ground wire manually and then the battery reconnects. Or there is a remote switch that can be installed inside the vehicle. I have a 2005 Infiniti FX.

san francisco
Would recommend to a friend?
great product
September 20, 2017
by on September 20, 2017

works like it say it will.

Would recommend to a friend?
Great product
January 5, 2017
by on January 5, 2017

After many attempts at trying to find the drain winter set in. I needed a dependable vehicle. I found this and installed in minutes. Works every time the care sits a long time. Now looking at getting one on each car so nobody in the family gets that awful click and no start. Thank you.

MN Dave
Would recommend to a friend?
It works! As advertised.
December 29, 2016
by on December 29, 2016

I have a Chevy Silverado 2010 the ones that has a constant draw enough to drain the battery in a week. I went 2 weeks already with it went to the truck turn on the lights shut them off and the truck started and the battery had more than enough power to start the truck. The only thing I don't like is the rubber band that holds the unit to the battery.

New York
Would recommend to a friend?
December 3, 2016
by on December 3, 2016


Would recommend to a friend?
battery protector
October 14, 2016
by on October 14, 2016

installed this on a Mercedes with multiple battery draw issues, cheaper to install this than to fix all the customers issues
only problem was the way Mercedes wires everything, if it disconnects it needs to see a load on the negative side of the battery, I had to wire in a push button switch to be able to do a reconnect after the battery voltage dropped.

Would recommend to a friend?
Savior for my 2008 Toyota Highlander Hybrid
January 12, 2016
by on January 12, 2016

The PriorityStart was a godsend for the huge oversight in the engineering of the 2008 Toyota Highlander Hybrid I bought a year ago. The Hybrid has a tiny 12V battery (like a garden tractor battery) which runs the computer, which allows the actual humungous hybrid battery to start the car. Well, this little baby battery would go dead all the time, sometimes for reasons unknown. And there I'd be stuck. After getting stuck three hours away from home on a Sunday night, I finally bit the bullet and sprung for the PriorityStart. Now when someone leaves a door ajar, or a dome light on, or someone forgot to push the button to turn off the smart key function, the battery only drops to 11.7 volts and then saves itself by cutting the power to everything. Yes, it is annoying when I lose my pre-sets for the radio and the clock, but it is no longer a life changing event. I push the brake pedal and the system re-sets and away I go. I have never been left stuck since. And this little baby battery has gone dead many times. Two things about the install: The rubber band they supply with this is a joke. Such a good product should be ashamed to even send something like this. After a somewhat tricky (but not crazy) install due to space limitations, about a week later the whole unit slid up on the battery, the positive cover slid off, and it was arching against the hood, causing the ABS system to judder and showing all kinds of warnings on the dash lights when hitting the brakes, especially going downhill. It was like it was shorting out the whole car! Very scary. My advice is to immediately throw away that rubber band (mine snapped) and find a more secure way to strap unit to battery (I used an industrial sized tie wrap). Then secure the positive post cover with another tie wrap, disallowing it from ever contacting metal. After draining the battery to zero multiple times before installing the PriorityStart, I probably should have replaced the battery AFTER installing this device. It's been about 8 months now, and this unit has kept peace between me and this otherwise decent vehicle. I would have sold it otherwise.

SE Pennsylvania
Would recommend to a friend?
The PriorityStart! 12 Volt ProMax Battery Protector has been cross-referenced to be compatible with or replace these OEM part numbers and models: