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Section 1: Power Systems

System Overview

The Jeep LJ uses a dual-battery electrical system with intelligent power distribution and programmable power management.

Power Generation & Storage

  • START battery: Odyssey PC1500 (850 CCA, 68 Ah) in driver wheel well - critical systems only
  • AUX battery: Dakota Lithium 135Ah LiFePO4 (108 Ah usable, heated BMS) in passenger wheel well - accessories, winch (jump start capable)
  • RedArc BCDC Alpha 50: DC-DC charger/isolator - batteries operate independently when isolated
  • 270A Alternator: Charges START battery, BCDC charges AUX battery from front

See Power Generation for complete details on batteries, alternator, BCDC, and solar charging.

Power Distribution

Both batteries use CONSTANT bus bars for organized distribution with individual circuit breaker protection:

The system replaces the factory TIPM with modular programmable controllers:

  • PMU24: 24-channel programmable power management - engine bay critical circuits
  • BODY PDU: Cabin convenience circuits - radio, USB, heated seats, camera
  • SafetyHub: High-current safety circuits - ARB compressor, winch contactor

Ground distribution architecture:

  • Grounding Architecture: Battery grounds, engine bay ground bus, firewall stud bus, distributed grounding system

Wiring Standards

Standard Specification Notes
Connections Soldered + marine heat shrink Waterproof, vibration-resistant
Connectors Deutsch DT series (IP68) Engine bay and exterior locations
Securing Every 12-18" High-vibration areas (engine bay, wheel wells, frame rails)
Securing Every 24" Low-vibration areas (cabin, trunk)
Loom Split loom or braided sleeving Abrasion protection where routed against metal
Grommets Rubber with sealant All firewall and body penetrations
Temp derating 60°C for engine bay Ampacity calculations must use derated values
Temp derating 30°C for cabin/wheel well Standard ampacity values acceptable

See Wire Distance Reference for routing distances and gauge specifications.