?160amp Alternator for '97 Previa LE/SC AllTrac...

[brughjoy]

Upgrading to 160amp from the stock 70amp so I can run an alternator charger to my Anker power station. Found Quality Power in Yucaipa California that will re-do mine and ship back to me the next day. Though this is my 4th Previa (just purchased last month) I'm just not knowledgeable enough to know what I'm doing so any help is greatly appreciated.

Harness/alternator to battery cables. What length and what gauge? I know I need something more robust than the stock cables but not sure if 2-gauge will do it or if I need 1-gauge?

Also, I heard I need a "fusible link". Is this a specialty/dealer/OEM item or something I might find on eBay.

Last question...any idea how I run the cable from the battery to the alternator charger...like places or ports in the firewall to run the cables through?

Big thanks,

:-) Jon

[skyshadow07]

So a company is going to alter your stock alternator to create 160 amps?! I didn't know this was a thing.

[brughjoy]

Here's the vendor...
https://www.qualitypowerauto.com/

and this is what Grok gave me to the question "How is it physically possible to rebuild a 70amp alternator to make it into a 160amp alternator?"...

Rebuilding a 70-amp alternator to produce 160 amps is physically possible by modifying key components to handle higher current output, but it requires careful engineering to ensure reliability and compatibility with the vehicle’s electrical system. Here’s how it can be done:


Replace the Stator: The stator generates the alternating current (AC) that the alternator converts to direct current (DC). To increase output to 160 amps, install a stator with thicker wire windings and more turns to produce a higher magnetic field and current. This may require a custom-wound stator, as the original 70-amp stator is designed for lower output.
Upgrade the Rotor: The rotor creates the rotating magnetic field that induces current in the stator. A higher-output rotor with stronger magnets or improved electromagnetic coils can increase the field strength, boosting current output. Ensure the rotor fits within the alternator housing and maintains proper clearance.
Install a High-Capacity Rectifier: The rectifier converts AC to DC. A 70-amp alternator’s rectifier may overheat or fail at 160 amps. Replace it with a heavy-duty rectifier bridge rated for higher current, often with larger diodes or a more robust heat sink to dissipate heat.
Upgrade the Voltage Regulator: The voltage regulator controls the alternator’s output voltage. A high-output alternator requires a regulator designed to handle the increased current and maintain stable voltage (typically 13.8–14.4V). Some high-output alternators use external regulators for better control.
Increase Wiring and Connector Capacity: The internal and external wiring, including output cables and connectors, must be upgraded to handle 160 amps without overheating. Use thicker, high-quality copper wiring with appropriate insulation and high-current terminals.
Enhance Cooling: Higher current generates more heat. Upgrade the alternator’s cooling system with a larger or more efficient fan, or ensure the housing allows better airflow. Overheating can damage components or reduce lifespan.
Reinforce the Housing and Bearings: The increased mechanical and thermal stress from higher output may require a sturdier alternator housing and stronger bearings to handle the additional load and prevent premature wear.
Match Pulley and Belt System: Ensure the alternator’s pulley size and type match the vehicle’s drive system. A high-output alternator may require more torque, so a stronger belt or adjusted pulley ratio might be needed to prevent slippage.

Practical Considerations

Physical Fit: The modified alternator must fit in the original mounting space and align with the vehicle’s belt system.
Vehicle Compatibility: The vehicle’s electrical system (battery, wiring, fuses) must support 160 amps. Upgrading the alternator alone without upgrading downstream components can cause overheating or failures.
Custom Parts: Many components (e.g., stator, rectifier) may need to be custom-made or sourced from high-output alternator kits, as stock 70-amp parts won’t suffice.
Cost vs. Replacement: Rebuilding can be complex and costly. In some cases, purchasing a pre-built 160-amp alternator designed for your vehicle may be more practical.

Limitations

Physical Constraints: The alternator’s housing size limits how much you can upgrade components like the stator or rotor.
Heat Dissipation: Even with upgrades, heat management is a challenge at 160 amps, potentially reducing lifespan if not addressed.
Engineering Expertise: Rebuilding requires precise calculations to balance output, heat, and mechanical stress. Improper modifications can lead to failure or damage to the vehicle’s electrical system.

This process is often done by specialized shops that rebuild alternators for high-performance vehicles or heavy-duty applications. If you’re considering this, consult with a professional alternator rebuilder or mechanic to ensure the modifications are safe and effective.

[brughjoy]

apparently it is a big business because of high end car audio systems. Those woofers take a lot of power!

[skyshadow07]

Interesting. I'm swapping to E fans and figured a few more amps wouldn't be a bad idea but I can't math out more than 70amps of load unless I had EVERYTHING turned on at once. When i say everything I mean...
Headlights (halogen, both) 10A *swapping to LED so more like 5A*
Taillights, marker lights 2–3A
Dashboard + cluster lights 1A
Heater, A/C blower (high) 10A
A/C clutch engagement 5A
A/C condenser fan 8–10A
Radio (OEM or low-power) 2A
Wipers (high) 4–6A
Fuel pump 3–5A
Ignition/ECU 5–8A
Cold start injector (brief use) 1–2A
Rear defogger 10–15A
Dome light / minor accessories 1–2A

My van is a weekend camper so I have 200ah batteries in the back that power a inverter for accessories.

[brughjoy]

Sounds like you're good to go.

My load audit pushed me to around 120 and the alternator guys I've contacted suggest leaving some headroom both for spikes and for alternator longevity.

We'll see!