Polaris RZR Pro R Auxiliary Alternator Kit | Power Your High-Amperage Accessories and Never Run Out of Juice
You flip the switch for your light bar, crank up the stereo, and watch your voltage gauge drop—it’s time to upgrade your Polaris RZR Pro R’s charging system.
Every Polaris RZR Pro R owner knows the feeling. You’ve added all the cool accessories—massive light bars, a thumping stereo system, extra cooling fans, maybe even a winch. But the moment you turn everything on, you see it: the voltage drops, lights dim, and you start worrying about getting stranded. The factory charging system on your RZR Pro R simply wasn’t designed for this much electrical demand. That’s where an auxiliary alternator kit comes in, and it’s a game-changer for anyone running high-amperage accessories.
TL;DR
The Polaris RZR Pro R’s factory charging system outputs 140 amps, which may not be enough for accessory-heavy builds. An auxiliary alternator kit adds significant additional amperage by bolting a second alternator directly to the engine. These kits typically include a modified stator cover, crankshaft pulley, alternator mounting bracket, belt, and wiring harness. Installation takes 1-3 hours for most kits and is a straightforward bolt-on process. The upgrade solves voltage drop issues, eliminates the need for secondary batteries in many cases, and ensures all your electronics run consistently.
Key Takeaways
- Factory system limitations – The Pro R’s 140-amp alternator is great for stock machines but struggles with heavy accessory loads
- Auxiliary alternator kits add real power – Most kits add 60-100+ additional amps to meet high electrical demand
- Bolt-on installation – Kits are designed as direct bolt-ons with no frame modification required
- Professional installation recommended – While DIY-friendly, the job involves engine components and electrical connections
- Eliminates second battery dependency – Proper alternator upgrades address the root problem, not just symptoms
Understanding Your Polaris RZR Pro R’s Electrical System
The Polaris RZR Pro R comes from the factory with a 140-amp alternator . That’s a solid charging system for a stock machine. The problem starts when you add accessories that pull serious power.
Think about everything running on a modern performance RZR:
- Lighting systems – LED light bars, rock lights, interior lights
- Audio systems – Amplifiers and speakers that draw significant power
- Cooling components – Radiator fans, intercooler fans
- Electronics – GPS, communications, navigation
- Performance parts – Aftermarket ECUs, fuel pumps
- Utility accessories – Winches, air compressors
When you’re running all these at once, the stock alternator reaches its limit. The result is voltage drops, dimming lights, and potential electrical system failures. Some riders try to solve this with a second battery, but that only stores more power—it doesn’t create it.
Here’s an important distinction many riders miss: a second battery gives you reserve power, but an alternator upgrade gives you more generating capacity. They serve different purposes, and for high-demand builds, you often need both.
Why You Need an Auxiliary Alternator Kit
The Real Problem: Voltage Drop
The factory charging system works well for stock machines. But as soon as you start adding accessories that draw continuous power, the system struggles. The most common symptoms include:
- Battery drain during normal riding
- Voltage drop when multiple accessories run
- Dimming lights at idle or low RPM
- Reduced accessory performance
- Charging system stress and premature failure
How Alternator Kits Solve These Issues
A properly designed auxiliary alternator kit addresses the root problem by increasing the system’s ability to generate power. Instead of relying on stored battery power, the alternator continuously supplies the charging capacity needed to support higher electrical demand .
Additional Benefits
Beyond the obvious power increase, there are some lesser-known benefits:
- Eliminates “limp mode” issues – Low voltage can trigger reduced engine performance modes
- Stable ECU operation – Modern ECUs need consistent voltage for optimal performance
- Longer component life – Electrical components last longer when they get proper voltage
Auxiliary Alternator Kit Options for Polaris RZR Pro R
Dirt Launch Powersports Kit
This kit is specifically designed for trail riders and racers who need reliable charging capacity. It features a crankshaft-driven alternator system that supports high electrical loads. The kit includes detailed installation instructions covering the modified stator cover, crankshaft pulley, alternator mounting, belt routing, and wiring connections .
Kraftwerks Pro Race Alternator Kit
Kraftwerks has developed Pro Race Alternator Kits specifically for RZR models. For the Pro R, they offer a +60 amp configuration that brings total output to 100 amps. The centerpiece is a custom CNC billet machined stator cover that retains and seals the external alternator drive system. All components are hard anodized for corrosion protection .
Key features of the Kraftwerks kit:
- 60-amp additional output
- CNC machined billet aluminum mounting
- Water-resistant design
- Complete with instructions, harness, belt, pulleys, and hardware
- 1-3 hour installation time
LaRue Performance Alternator Kit
For extreme power needs, LaRue Performance offers a 195-amp marine-style alternator. This is compatible with all Polaris RZR models from 2014 and up. The marine design means you don’t have to worry about water exposure. It’s a bolt-on kit with no frame modification needed .
Key features of the LaRue kit:
- 195-amp output (up to 150 amps at idle)
- Marine-style alternator (water-resistant)
- No frame modifications required
- Bolts directly to the crank
- Made in the USA
- All hardware included
What’s Included in a Typical Auxiliary Alternator Kit
Most quality kits include everything you need for installation:
| Component | Purpose |
|---|---|
| Modified stator cover | Seals and retains the external alternator drive system |
| Crankshaft pulley | Drives the alternator belt |
| Alternator mounting bracket | Secures the auxiliary alternator |
| V-belt or stretch belt | Connects the system components |
| Wiring harness | Connects the alternator to the electrical system |
| Hardware | All bolts and fasteners needed for installation |
| Gaskets | For proper sealing of the stator cover |
| Instructions | Detailed step-by-step installation guidance |
Installation Overview for Your Polaris RZR Pro R
Tools You’ll Need
Before starting, gather these tools:
- Socket set with metric sizes
- Torque wrench
- Basic hand tools (screwdrivers, pliers)
- Jack and jack stands (or a lift)
- Safety glasses and gloves
Step-by-Step Installation Process
Step 1: Preparation
Disconnect the battery. Remove any components blocking access to the stator cover area. This may include skid plates, frame guards, or other under-vehicle components.
Step 2: Remove the Factory Stator Cover
The factory stator cover needs to be removed to access the internal components. Some kits replace this entirely, while others modify it. You’ll need to drain the oil if the cover affects oil capacity.
Step 3: Install the Modified Components
Install the new or modified stator cover according to the kit instructions. This typically includes new gaskets and proper torque specifications.
Step 4: Mount the Crankshaft Pulley
The new pulley attaches to the crankshaft to drive the alternator belt. This is a critical step—proper torque is essential.
Step 5: Mount the Auxiliary Alternator
Using the provided brackets, mount the alternator in its designated location. This should be a direct bolt-on with no additional modification needed.
Step 6: Install the Belt
Route the belt according to the instructions. Some kits use V-belts, others use stretch belts. Proper tension is crucial for both performance and belt life.
Step 7: Connect Wiring
Route and connect the alternator wiring harness. Most kits are plug-and-play, but you may need to connect directly to the battery.
Step 8: Test System
Before reassembling everything, reconnect the battery and test the system. Verify the alternator is charging properly and no error codes appear.
Step 9: Reassembly
Replace any removed components, check for proper clearance, and go for a test ride.
Here’s a pro tip: Take photos during disassembly. These visual references can be incredibly helpful if you need to refer back during reassembly.
Timeline: The Evolution of Polaris RZR Charging Systems
2007Original Polaris RZR introduced with basic electrical systems
2010sAftermarket accessories boom, revealing factory charging limitations
2014First wave of dedicated RZR alternator kit solutions emerge
2022Polaris RZR Pro R launched with 140-amp factory alternator
2024High-output auxiliary alternator kits reach advanced capability
TodayMultiple options provide 100+ additional amps for heavy-demand builds
Real-World Impact: Why This Upgrade Changes Everything
Before and After
Before:
You’re on a long trail ride, running lights, music, and GPS. The voltage gauge starts dropping. Your lights dim. The ECU pulls power to protect itself, and you feel a loss of performance. You worry about getting stranded.
After:
You load up the accessories, and the voltage stays solid. The lights don’t flicker. The music keeps playing. The ECU has all the power it needs to keep the engine running strong. You enjoy the ride without constant worry.
Real User Experience
“One of the most common questions RZR owners ask is: ‘Do I need an alternator kit for my Polaris RZR?’ The answer depends on how much electrical demand you’ve added to the vehicle. For many trail riders and race teams, the factory charging system eventually reaches its limit. That’s where a Polaris RZR alternator kit becomes one of the most valuable reliability upgrades you can make.”
Supporting Your Accessories
Auxiliary alternator kits are particularly valuable when running:
- Race vehicles with high-performance electronics
- Turbocharged RZR builds with extra cooling needs
- Audio-equipped machines with powerful amplifiers
- Multi-accessory vehicles running lights, winches, and more
- High-demand electrical systems in general
Are You a Candidate for This Upgrade?
You Should Consider an Auxiliary Alternator Kit If:
| Situation | Why You Need It |
|---|---|
| Voltage drops consistently | Your current system can’t keep up |
| Lights dim at idle | Not enough charging at low RPM |
| Multiple cooling fans installed | Electric fans draw significant power |
| Aftermarket stereo installed | Amplifiers are major power consumers |
| Winch installed | Winches draw massive current |
| Multiple light bars installed | LED bars draw more than they appear |
| ECU upgrade planned | Performance ECUs need stable voltage |
You Should Consider a Dual Battery Instead If:
| Situation | Why You Need It |
|---|---|
| Engine off accessory use | Alternator only works when engine runs |
| Need backup for emergencies | Second battery provides insurance |
| Already have strong charging | Focus on storage capacity instead |
The reality is that many serious builds benefit from both—an upgraded alternator for charging capacity and a dual battery for engine-off accessory use and redundancy.
Factory Alternator Specifications
For reference, here’s what the Polaris RZR Pro R uses from the factory:
Stock Alternator: 140 amp output
Related Components:
- Alternator cover
- Alternator bracket
- Intermediate bracket
- Lift bracket
- Stretch belt
Safety Considerations
“Do not arrange fuses improperly or use replacement fuses with improper amperage values. This could lead to electrical overload, which can result in severe injury or death.”
Always: Follow proper wiring practices. Use appropriate circuit protection. Ensure all connections are clean and secure. Route wires away from moving parts and heat sources.
Never: Bypass factory fuses. Use improper gauge wiring. Ignore warning signs of electrical issues. Work on the electrical system with the battery connected.
Frequently Asked Questions
How much does an auxiliary alternator kit cost?
Kits range from approximately $1,500 to $2,500 depending on brand and output capacity .
Is installation difficult for the average RZR owner?
Most kits are designed for bolt-on installation with detailed instructions, though professional installation is recommended .
How long does installation typically take?
Installation usually takes 1-3 hours for experienced mechanics .
Will this void my Polaris warranty?
Aftermarket modifications may affect warranty coverage for related components—consult your dealer.
Do I need a second battery if I install an alternator kit?
Not necessarily—the alternator upgrade often eliminates the need for a secondary battery in many applications .
What’s the difference between the stock alternator and an auxiliary kit?
The stock alternator provides 140 amps, while auxiliary kits add 60-100+ additional amps for total increased capacity .
Final Thoughts: Power Up Your Ride
The Polaris RZR Pro R is already an incredible machine. But if you’re running serious accessories, you’re leaving performance on the table by not upgrading the charging system. An auxiliary alternator kit isn’t just about running lights and stereos—it’s about ensuring your vehicle performs consistently and reliably every time you hit the trail.
The days of watching your voltage gauge drop and worrying about getting stranded are over. With the right auxiliary alternator kit, your Pro R will have all the power it needs to run everything you’ve installed and more. The installation is straightforward, the benefits are immediate, and the peace of mind is priceless.
What’s your favorite Polaris upgrade or trail experience? Share your thoughts in the comments below.
References
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