PriorityStart! ProMax HD 12V Car & Truck Automatic Battery Start Protector
Item #: 12V-PROMAX-HD   |    In Stock

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PriorityStart! ProMax HD 12V Car & Truck Automatic Battery Start Protector

Item #: 12V-PROMAX-HD   |  In Stock

Today's Price: $129.95
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Price: $129.95

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1 Year Factory Direct Warranty
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Product Specifications for PriorityStart! ProMax HD 12V Car & Truck Automatic Battery Start Protector

BM Part #: 12V-PROMAX-HD
Voltage: 12 Volt
Length: 5"
Width: 3"
Height: 1.25"
Shipping Weight: 3.00Lbs
Warranty: 1 Year Factory Direct
Product Manual: Download
  • Handles over 1600 starting amps.
  • Handles approximately 400 continuous amps.
  • Disconnects at 11.7V; times out after approximately one (1) minute.
  • Reconnects with 0.2mV load change (brake pedal, light switch, etc.).
  • High intensity LED light indicates connect/disconnect status.
  • Temperature range: -40°F to +185°F.
  • This item is covered by the Replacement Only Return Policy.
  • PriorityStart! 12V ProMax H.D. provides even stronger Automatic battery protection for heavy duty vehicles and multiple accessory (2way/CB radios, radar, GPS dual batteries etc.) applications
  • Heavy duty increases on all internal components, circuitry and materials, providing greater strength and durability to a wider range of vehicles and applications
  • Designed to handle 1600 starting amps and up to 400 continuous amps providing heavier load capacity, Top high intensity LED indicates connect/disconnect mode
  • 20 Years Same proven technology Automatically Disconnects any drain on battery when engine is off, then Automatically Reconnects with small load change (put foot on brake pedal, operate light switch, etc.) Do-It- Yourself Install.
  • No buttons to push, no raising the hood, no remote to carry and no hard wiring no down time, no lost man hours, no damaged alternator or damaged electrical system. NO DEAD BATTERY!

Product Description

Free Standard Shipping!

Order today and receive free standard shipping on your PriorityStart! ProMax HD 12V Car & Truck Automatic Battery Start Protector. Only valid in the contiguous 48 states and not valid with any other offer.

PriorityStart! a TOTALLY AUTOMATIC 12 or 24 volt Electro-Mechanical computerized on/off battery protection system 20 years proven technology. Simple Do-It-Yourself 3 easy step installation. Stops battery from going dead, preventing damage to battery, alternator, and electrical system (surge protection). Monitors battery voltage when the engine is off. If battery voltage drops below 11.7V (23.6V for 24V model) for any reason, PriorityStart! Automatically Disconnects the drain, leaving starting power! To start the engine, simply operate brakes, lights, accessories, (bilge pump on boat) any small load change (0.2mV) and PriorityStart! Automatically Reconnects, you can start the engine. No raising the hood, No remote to carry, No button to push, No Dead Battery. The PriorityStart! 12 volt ProMax battery protector pays for itself the first time it saves a battery. A dead battery costs time, money, and permanently damages the battery. Protect your battery's life and power with PriorityStart! See each model for more specifics.

Current models include LED light.

Easy to Attach!

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

Specially designed for Law Enforcement, Fleets, Utility, Emergency, and Security vehicles with multiple accessories. PriorityStart! 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 1600 “starting amps”.

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

PriorityStart! 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! 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

What improvements does the PriorityStart! HD have over the original 12V-PROMAX?

  1. 1600 Starting Amps, 400 Continuous Amps.
  2. Contact disk upgrades:
    • Contact disk approximately 60% area increase for more load carrying capability.
    • Spline gear and holding nut increased approximately 60% providing heavier load carrying capability, thus decreasing strain and stress.
  3. Jack screw increased approximately 40% to provide heavier load carrying capability.
  4. Busses increased approximately 30% to provide more load carrying capability.
  5. Ground wire connector thicker and stronger allowing use on heavier vehicles.
  6. Top post contact material increased and raised to improve new GM connections.
  7. Gear cover protects from outside debris, the single solid cover is strong and durable and suppresses normal gear noise.
  8. Motor cover protects from outside debris, the single solid cover is strong and durable.
  9. High intensity LED light, moved to top of unit.
  10. Redesigned circuit board, with room for future expansion.

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Customer Reviews

13 Reviews | 4.9 out of 5
5 stars (12)
4 stars (1)
3 stars (0)
2 stars (0)
1 star (0)
Would recommend this product.
What our Customers are saying
ProMax HD 12V Car & Truck Automatic Battery Start Protector
July 30, 2023
by on July 30, 2023

I bought this product in hopes it would help aid in trucks parasitic battery draw. The product has been working as described. I recommend this product for piece of mind.

Glen Rock Pa.
Would recommend to a friend?
Priority Start! Works Well
June 24, 2020
by on June 24, 2020

I installed and have tested the heavy duty version of Priority Start! on my 2001 Toyota Land Cruiser because it appeared to have a parasitic battery drain problem. Since the vehicle has no mechanical key alternative to its battery-powered locks, I installed an "always-on" momentary switch in the Priority Start! ground wire. If the Priority Start! is activated, shutting down the battery at 11.7 volts as advertised, I am now able to press the switch, which would momentarily disable the Priority Start!, thereby reconnecting the battery long enough to unlock the doors and enter the vehicle. I then will be able to start the car with the remaining voltage in the battery guarded by the Priority Start!, as the instructions indicate. In a chat session, an advisor at Priority Start! suggested this modification (the always-on, momentary-off switch) to compensate for avoiding the potential of getting locked out of my vehicle if the battery is shut down by the Priority Start!, which is its purpose. To prevent tampering from potential thieves, I mounted the momentary switch in an accessible but secret location outside the vehicle. Sorry, I'm not telling where that is.

My main concern with automatic kill switches, such as Priority Start!, was that if I had the vehicle parked in an airport parking lot for two or three weeks, the likelihood of the parasitic battery drain activating the battery shutdown by the Priority Start! would be relatively high. Flying in late at night, I might be greeted with a car with a good battery, but I would be unable to unlock the car because the Priority Start! had disabled disconnected its battery. No fun at midnight in an airport parking lot.!

Many newer vehicles have mechanical backup keys, so for those, there would be no problem.

I give the product a 4-star rather than a 5-star rating only because I think Priority Start! should have built into the device itself a way of working around the potential of getting locked out of electric-lock-only vehicles that have no mechanical back-up method of unlocking. Perhaps they will see this review and consider this as a possible improvement on an otherwise very good product.

Notthat Dumb
Would recommend to a friend?
Priority Start
March 3, 2020
by on March 3, 2020

I have a parasitic drain on my vehicle. The car has been brought back to the dealer numerous times with the complaint of the battery going dead. The dealership replaces the battery, but does nothing further to resolve the problem. The hassle of having to jump the car when the battery keeps going dead and visiting the dealer forced me to look for a different solution. So I purchased a "Priority Start". Installation was simple and to date I haven't had any battery issues. Hopefully the dying battery issue is resolved.

Would recommend to a friend?
works as advertised
November 1, 2019
by on November 1, 2019

Easy to install. No problems. The winter will tell me how good this device is.

Mike G.
E. Northport NY
Would recommend to a friend?
An improved design
August 17, 2019
by on August 17, 2019

An improved design. I like the indicator light on top. But will this HD version last longer than the standard version that failed on me did?

Would recommend to a friend?
PriorityStart! 12 volt ProMax
May 3, 2019
by on May 3, 2019

Just what I ordered.

Would recommend to a friend?
Great product for a huge need!!!!
September 2, 2018
by on September 2, 2018

No more dirty hands or dead battery.

Would recommend to a friend?