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High Output Alternators

Why Upgrade to a High Output Alternator?

The alternator can be the backbone of a charging system. With a high output alternator, every minute that the engine is running can be utilized for maximum charging capabilities. High Output alternators provide:

  • 2-3 times the charging current of a factory alternator
  • As much as 5 times the output of a factory alternator with a dual alternator setup
  • Reduced fuel consumption due to higher efficiency charging

Considering an upgrade to your alternator? There are several important factors to keep in mind to ensure you make the best choice for your needs.

Our Suppliers

American Power Systems

  • Highest output small case alternators
  • 28V & 56V applications
  • Highest output large case alternators
  • Isolated Ground available on higher output alternators which allows monitoring
  • Can be used in some cases where the Balmar alternators will not fit
Balmar logo


  • Lower cost 12V small case high output alternators
  • Pulley kits for all alternator upgrades
  • Recognized throughout the industry for its innovative technology, expert technical service and product reliability
  • Lead time might be shorter because units are in stock

American Power Systems, Inc

Highest output alternators for the stock position

All are available with isolated ground and some are available with J180 mount. See price sheet link to the right.

HPI-255-EXT-1414 V255 A17 lbs.
HPI-360-EXT-1414 V360 A17 lbs.
HPI-185-EXT-2828 V185 A17 lbs.
HPI-160-EXT-56V56 V160 A17 lbs.

55i-360EXT-14V-IG14 V360 A32 lbs.
55i-270-28J-IG (low rpm startup)28 V270 A32 lbs.
55i-300A-28V28 V300 A32 lbs.
55i-360ACT-28J-IG28 V360 A32 lbs.
55i-190-56V-IG56 V190 A32 lbs.


Small Case Alternators

Available with DV, K6 & J10 pulleys

ModelVoltageRatingMounting Options
XT-17014 V170 A1”, 2”, 3.15”  Yanmar
XT-170-IG14 V170 A3.15” Yanmar/Hitachi saddle
XT-25014 V250 A1”, 2”, 3.15” Yanmar, J180/4”
Extreme heat warning sign

Heat Management

The biggest challenge when upgrading to a high output alternator is managing the heat created while charging. Enough space and forced air flow in the engine room can help to keep the temperature down but in the case that it is getting dangerously hot, a properly mounted temp sensor with a smart regulator programmed to dial back appropriately are a must for safety. 

Upgrading to a Serpentine Pulley Kit

When upgrading to a high output alternator, it is necessary to upgrade to a serpentine belt pulley kit.  A serpentine belt provides better surface contact to the pulleys which allows for better power transfer from the engine to the alternator, less vibration & a longer lasting system. Balmar pulley kits are available for many engine types & are designed to improve lower RPM charging & achieve faster charging times.

Installation Can Be Tricky

Each alternator & pulley kit upgrade should be viewed as a custom job.  There are minor differences between engine models by year, variations in installations, and engine compartment differences that make each upgrade a unique situation.  Even with the best measurements & fabrication, the installation will require some tweaking & testing for proper operation. Check out this customer blog with a helpful & thorough explanation of the entire upgrade and installation process.


Alternator Regulators

An alternator regulator is necessary to adjust the voltage coming out of your alternator to the level that your battery bank needs. A regulator is also necessary to protect your engine and alternator by making adjustments according to environmental conditions. Choosing the best alternator regulator will ensure that you get the most out of your charge cycle. The most advanced regulators, such as the AP500, are also capable of interfacing with the engine so that the alternator is always charging at peak efficiency. Additionally, OPE has developed a web browser interface for the AP500 which allows users to easily access the most advanced programming & monitoring options.