DuroMax XP9500iH Auto-Start Wiring

EG4 6000XP INVERTER  →  GENSTART BASE CONTROLLER  →  DUROMAX XP9500iH
ACIDNI LLC  |  JULY 2026  |  REV 2.0
EG4 6000XP INVERTER 51.2V LiFePO4 BANK • 6 × 100Ah • 30.7 kWh GENERATOR START DRY CONTACT NO1 COM1 CLOSES at 45% battery — start OPENS at 90% battery — stop GEN AC INPUT — 120/240V (already wired) WHITE BLACK GENSTART CONTROLLER BASE MODEL  •  WEATHERPROOF ENCLOSURE ALL CONNECTIONS ARE LABELED SCREW TERMINALS START SIGNAL IN SIGNAL COMMON GENERATOR START/STOP START/STOP 1 START/STOP 2 12V POWER IN BATTERY + BATTERY − GENERATOR RUNNING SENSE AC SENSE L AC SENSE N SETUP (in the GenStart app / web page) Start Mode: BUTTON  •  Double-Press: OFF Hold 3 sec to start  •  hold 3.5 sec to stop DUROMAX XP9500iH DUAL-FUEL INVERTER • AUTO-CHOKE • KEY-FOB REMOTE START / STOP PUSH-BUTTON on the generator control panel its two wires TAP IN PARALLEL — DO NOT CUT ANYTHING GENERATOR 12V STARTING BATTERY + − install supplied 3A inline fuse on the + wire ANY 120V OUTLET ON THE GENERATOR HOT NEUTRAL ONE 120V LEG ONLY — never across 240V L14-30 OUTLET — 120/240V SPLIT PHASE → EG4 GEN AC INPUT (your existing cable) FACTORY WIRELESS KEY FOB KEEPS WORKING — NOTHING IS DISABLED LEAVE THE GENERATOR SET UP LIKE THIS • START-UP (power) switch — ON • Fuel valve open, oil level good • Low-idle (ESC) OFF • battery maintainer 2-wire GENERATOR POWER → EG4 GEN INPUT → CHARGES THE BATTERY BANK WHAT HAPPENS, STEP BY STEP 1. Bank reaches 45% — the EG4 closes    its generator start contact 2. GenStart waits 3 seconds 3. Holds the START button 3 seconds —    the auto-choke handles the rest 4. Confirms real AC power within 15 sec;    if not, waits 10 sec and tries again    (3 tries, then reports a fault) 5. EG4 accepts the power and charges 6. Bank reaches 90% — EG4 opens the    contact, GenStart holds the button    3.5 seconds and the engine stops

Connection Summary

GenStart TerminalConnects ToWire
START SIGNAL — SIGNALEG4 6000XP generator dry contact, NO1White, 22 AWG
START SIGNAL — COMMONEG4 6000XP generator dry contact, COM1Black, 22 AWG
START/STOP 1One wire of the DuroMax START button (tapped in parallel)Green, 18 AWG
START/STOP 2The other wire of the same button (tapped in parallel)Green, 18 AWG
BATTERY +DuroMax 12V starting battery, positive post — 3A inline fuse requiredRed, 18 AWG
BATTERY −DuroMax 12V starting battery, negative postBlack, 18 AWG
AC SENSE LHot side of any 120V outlet on the generator — one leg onlyOrange, 18 AWG
AC SENSE NNeutral side of the same outletWhite/Orange, 18 AWG
— (no GenStart terminal)L14-30 → EG4 GEN AC input stays exactly as it is todayExisting cable

Settings — GenStart Web Page

SettingValue for the XP9500iHWhy
Start ModeButtonThe XP9500iH has no two-wire start input; its panel button is the control point
Double-Press GapOff (single press)One press-and-hold starts this generator
Press Length (Start)3 secondsManual: hold the START button until the light turns green
Press Length (Stop)3.5 secondsManual: hold the button about 3 seconds to shut down
Start Confirm Time15 secondsAC power must appear within this window or the attempt counts as failed
Retries / Retry Delay3 / 10 secondsAutomatic re-try; after 3 failures GenStart stops and reports a fault
NOTHING FACTORY IS MODIFIED: The two START/STOP wires splice alongside the existing button wires (posi-taps or solder and heat-shrink). No wire is cut. The choke (automatic), ignition, fuel system, and wireless key fob are untouched and keep working.
AC SENSE — ONE LEG ONLY: Take hot and neutral from a single 120V receptacle. Never connect the sense leads across both hot legs (240V).
SOC THRESHOLDS: Set 45% start / 90% stop in the EG4's own menu. GenStart simply follows whatever the EG4 contact does.
PROPANE: If you switch fuels, the tank valve must be left open for unattended starting to work.
SAFETY: Disconnect the generator battery before you begin wiring.
Start signal from the EG4
Start/stop button wires
12V battery power
AC sense (generator running)
120/240V power to the EG4
Negative / common
© 2026 Acidni LLC. All rights reserved.
GenStart™ is a product of Acidni LLC. This document is provided for use with genuine GenStart controllers and may not be reproduced or redistributed without written permission.
DuroMax® and EG4® are trademarks of their respective owners and are referenced here for compatibility identification only. Acidni LLC is not affiliated with, endorsed by, or sponsored by any generator or inverter manufacturer.
Installation involves 12V DC and 120/240V AC circuits. Follow all applicable electrical codes and the manufacturers' safety instructions. If you are unsure, hire a licensed electrician.
support@acidni.net  •  genstart.acidni.net  •  Rev 2.0 — July 2026