Hybrid Battery FAILURE? No… Something Much Worse. Full BMW G12 Rescue!

In today’s episode, we take on a BMW 7 Series G12 Hybrid that broke down after a scraping impact under the car. What looked like a simple “12-volt battery light” turned into a full high-voltage investigation, battery removal, relay testing, programming, charging, and a complete safety box + SME replacement. This video is packed with real technical insights, the full diagnostic path, live data, bench charging, relay testing, IGBT damage explanation, battery state-of-health analysis, and the true cost of repairing this BMW hybrid. If you own a BMW hybrid (G12, G30, 530e, 330e), this video will teach you exactly what happens when the HV system stops charging the 12-volt battery — and how to avoid a £6,000 disaster. 📍 Visit Us: OGS Mechanics Units 9–14, Millers Yard Rear of 28 Long Lane London N3 2QG 📺 Watch Our Repairs in Action: 📌 Subscribe on YouTube → Weekly EV/Hybrid breakdowns, fixes & full diagnostics 📲 Follow the Behind-the-Scenes Garage Life: 🎵 TikTok: https://www.tiktok.com/@ogsmechanics 📸 Instagram: https://www.instagram.com/ogs_mechanics 📘 Facebook: https://www.facebook.com/share/15J54KFwjE/?mibextid=wwXIfr ⏱ Timestamps 00:00 – Breakdown story: Battery light after scraping underneath 01:20 – Vehicle check-in & first symptoms 02:20 – Diagnostic setup & initial tests 03:00 – High-voltage scan results 04:10 – Suspected HV connector issue 05:00 – Underside inspection 08:00 – Error codes change—software update attempt 09:10 – Battery too low for programming: EV no-win scenario 10:00 – Relay operation test explained 11:00 – Battery removal plan 13:00 – AC system draining (battery is AC-cooled) 15:10 – Opening the G12 HV battery 16:50 – Identifying relays & safety fuses 18:10 – Bench charging setup 21:00 – Strip-down of safety box 23:00 – Relay testing — finding the FAULTY one 27:00 – Why we chose NEW parts 28:30 – Preparing components for reassembly 31:00 – Battery refitting 35:00 – Programming & final setup 36:30 – Battery stats: SOH, voltage & capacity 38:30 – Real-world range test 45:00 – Final mileage achieved 48:00 – Unexpected issues: wiper motor & rear lights 50:00 – Why these components failed 52:00 – Complete repair recap & costs 56:00 – Total repair price revealed 57:00 – Final thoughts & advice #BMWHybrid #BMWG12 #BMWRepair #HybridRepair #EVRepair #HighVoltageBattery #OGSMechanics #CarRepair #MechanicLife #HybridSystem #EVProblems #BMW7Series #AutoRepair #WorkshopLife #ElectricVehicles