Forum Discussion

MEXICOWANDERER's avatar
MEXICOWANDERER
Explorer
Apr 13, 2015

Separate Alternator Rectifier For HOUSE Batteries

I've been venting about these things for years on this forum. The alternator 3 stator leads are tapped inside the alternator. Depending on the power rating of the alternator (3) 8 gauge or 6 gauge wires are run from the alternator to near the house batteries. This box is installed and wired. The alternator will run about 25% cooler,the regulator and the rectifiers inside the alternator have all the heat relieved and the alternator will last a lot longer. These things are great, with a proven track record of improving alternator reliability and much improved charging ability to motorhome house batteries. The link points to a reasonably-priced external rectifier. The rectifiers in the alternator continues to power the chassis.


External Rectifier
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Apr 14, 2015
    You may gain 30-amps. Most alternator voltage regulators use a thermistor in the integral voltage sense lead circuit. Start up cold regulated voltage set point may be 14.2 when the alternator gets hot the voltage may slump to 13.6. A cooler alternator is a happier alternator. Feeding ambient air forced with a fan through a duct tube to the rear of an alternator is a good though impractical sounding idea. But I like it :)
  • Gjac's avatar
    Gjac
    Explorer III
    Apr 14, 2015
    Is there a poor mans solution to cooling the internal rectifier say with an air duct that will accomplish almost the same thing? How much more amps will a cooler running rectifier input to your batteries? For example how many amps will 2 6 v GC 230 AH see from a 180 amp alternator at 50% SOC VS a cooled rectifier? Always enjoy reading your posts.

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,190 PostsLatest Activity: Jan 23, 2025