Honda CB 400 Super Four Battery Charging Issue | Stator Test + New Rectifier Installed

If your motorcycle battery shows 13V at idle but the voltage drops as soon as you increase RPM, then your charging system is failing, and the battery will stop charging completely.

This video explains exactly how to diagnose and fix this problem.

In my case, the symptoms were:
🔻 Voltage drop when revving
🔻 Battery not charging
🔻 Battery getting weak over time
🔻 Erratic voltage readings above idle

The issue is usually caused by either:
1️⃣ A faulty stator coil, or
2️⃣ A defective rectifier/regulator

In this video, I show:
✔ How to check the stator using simple multimeter tests
✔ What AC voltage readings you should get
✔ Why a bad rectifier can cause voltage drops
✔ The difference between original oval-hole rectifiers and fixed-hole ones
✔ How I mounted the new rectifier (AliExpress) despite the hole mismatch
✔ And how the charging problem was fully fixed after installation

A special thanks to Muttaqi Mazhari from Karachi, a wonderful young enthusiast who has been guiding me throughout my troubleshooting journey. We have never met personally, but he has helped me selflessly, always responding with detailed guidance and genuine support. Truly grateful for his help.

If this helps you diagnose your own bike, make sure to Like, Comment, and Subscribe for more motorcycle fixes and rides!

🎵 Music Used (Safe Credit — Fully Compliant with Epidemic Sound)
Track: Analog Dreams – Blue Saga
Licensed via Epidemic Sound (epidemicsound.com)

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