Mastervolt 45513000 Alpha Pro III Alternator Regulator

Alternator Compatibility: N-Type Only
System Voltage: 12V or 24V
Max Operating Voltage: 40V
Current Draw: 150mA
Max Field Current: 20A
Battery temp Compensation:– 30mV/°C@12V *
Alternator current support: up to 400A
Battery return current: 6% of max AH
Comes with: Wiring loom for Mastervolt alternators, Battery temperature sensor, MasterBus terminator, User manual
Optional connections: D+ lamp, tachometer, battery isolators,

See wiring diagrams and consult the manual for different wiring configurations and alternator support. There is also extensive troubleshooting help on the manual for common issues

Mounting Screws: 2x #5

A Bosch alternator can be used with the Bosch conversion cable kit (PN: 45510500)

Please consult the manual linked below to correctly configure your regulator and how to wire it

You will need a Mastervolt & CZone USB Interface Programming Tool and Masteradjust software to program and configure your Alpha Pro III Regulator, and you will need installer access to unlock the regulator. Call us and we can assist with your programming.

Temperature sensor: You can choose optionally battery temp(included) or alternator temp sensors (PN:41500400) to hook up 3rd party alternator sensors.

We recommend using a battery temp sensor if you have flooded/agm batteries sensitive to temperature. If you are charging lithium batteries, which can take nearly all the current available from the alternator, we strongly recommend the alternator temp sensor to prevent alternator over heating PN:41500400.

The reason we call this out is lithium can easily charge with 100% of it's rated amp hour capacity, much more than AGM and flooded, making alternators the temperature bottleneck. Refer to the alternator manufacturer for the best place and temperatures of the alternator in order to fill out at which temps to derate and increase voltage. And check out our assortment of ElectroMaax remotely rectified alternators which are designed to reduce the heat by 50% and ideal for charging lithium batteries.

Note: When configuring the regulator the RPM data in MasterAdjust configuration tab is for the alternator RPM, not the engine RPM.

The Alpha Pro III external alternator regulator is a critical component for optimizing and integrating charging of your batteries. Particularly when paired with Mastervolt MLI batteries.
What makes this so critical with Mastervolt MLI Batteries?
-Stop charge events which stop alternator charging to the battery when the battery requests it.
-Battery safety features which stop the regulator from creating power when the battery is having a battery safety event. This eliminates alternator backfeed which is a risk with other brands lithium battery BMS shut downs. But the Alpha Pro III solves that problem when paired with Mastervolt MLI due to the communication on Masterbus.
-RPM based events can now all be configured with a
-Small engine RPM programmable can limit the amount of load on the engine at low RPM to prevent stalling of small engines at idle.

Like any good external regulator the Alpha Pro III must be configured prior to operation. Make sure to follow the instruction manual, and also your alternator manual.

Comments and Recommendations for programming below:

1) The RPMs noted in the software are all referring to alternator RPM, not engine
2)You must log in to the Masteradjust software in order to get permission to unlock the Regulator Permissions
3) Areas of focus: Battey charging voltage, Battery type, Pole pairs (given by alternator manufacturer). Pulley ration, Correct temperature sensor (battery or alternator mount)
4)Pole pairs can be confusing, if an alternator claims to have 12 poles, then in the regulator it should be set up to have 6 pole pairs.
5) Pulley ratio: Motor pulley diameter divided by alternator pulley diameter, you can measure this without removing anything other than the shroud. Example crankshaft is 8in, alternator pulley is 2in, the pulley ratio would be 8/2 = 4.
6) Shunt device: shunt used on the battery being charged, can be a shunt or MLI batteries with internal shunts.
7) 100% Field >:field current will be at 100% above this alternator RPM, think of this as the RPM at which you want max power
8)20% Field <: field current will be at 20% below this alternator RPM, think of this as the RPM at which you 20% power.

Give us a call for any questions you may have when programming.