Charging via Generator (Victron / TBB)

Overview
If you’re off-grid and shore power isn’t available, a portable generator is your next best option to charge the caravan. The Victron MultiPlus-II Inverter/Charger will automatically detect the generator input and begin charging the battery — but to avoid generator stalling, you must set the system up correctly using Power Assist.

1. Generator Type: Bonded or Floating Neutral

The Victron MultiPlus-II Inverter/Charger is designed to work with both bonded and floating neutral generators.

  • The system automatically detects the generator’s AC input type and adjusts its internal configuration to ensure:
    • Proper grounding
    • Safe operation of RCDs (Residual Current Devices, also known as ground fault protection)

There’s no need to manually bond the neutral or modify your generator — the system handles it internally for safe and correct operation.

However, if a fault is shown (e.g. no earth or RCD tripping), this may indicate:

  • A wiring issue with the generator plug
  • An incompatible generator model or poor grounding on the generator frame

When in doubt, consult your Harvok technician or the Victron MultiPlus-II manual.

2. Why Generators Stall — and How to Prevent It

Generators may stall if the caravan draws more current than the generator can supply.

Example:
A 3000VA (3kVA) generator typically supplies up to 12 Amps. If your van tries to pull 15A or more (e.g. with air conditioning + microwave), the generator may overload and shut off.

[Victron] 3. Victron Power Assist: Seamless Support

The Power Assist feature in your Victron MultiPlus-II prevents stalling by intelligently blending generator and battery power.

How it works:

  • You set a safe AC input limit (e.g. 11A for a 3kVA generator).
  • The inverter will only draw 11A from the generator.
  • If you use more than 11A in the van (e.g. 20A), the inverter supplies the extra 9A from the battery.
  • This prevents overload while still powering your appliances.

[Victron] 4. How to Set the Generator Input Limit (AC Input)

Caution: Only adjust these settings if you’re confident, or consult a Harvok technician.

To change the AC input limit:

  1. Go to your Victron Digital Multi Control panel.
  2. Use the rotary knob to select a current limit (e.g. 10A or 11A).
  3. The new limit controls how much current the system will draw from the generator.

[Victron] 5. General Setup Instructions

To charge your van with a generator:

  1. Start the generator and let it warm up (2–3 minutes).
  2. Plug a 15A power lead from the generator into the caravan’s driver-side power inlet.
  3. Ensure the AC Input Limit is correctly set.
  4. The Victron inverter will switch to charging mode and begin supplying 240V AC to appliances.
  5. If more power is needed than the generator can provide, Power Assist will supplement with battery power automatically.

Generator Sizing Recommendation

  • Minimum Capacity: 3000VA (3kVA) recommended
  • Must output pure sine wave, 230–240V AC, 50Hz

[Victron] Technical Reference Victron Models

  • Inverter Model: Victron MultiPlus-II 48/3000/35-50 230V
  • Max Charge Rate: 30A at 48V
  • Compatible Input: Shore power or neutral bonded generator

📘 Victron MultiPlus-II Inverter/Charger Manual (AU Model)

📘 Victron Digital Multi Control – Operating Manual

[TBB] Introducing the Power Assistant Feature:

To address the challenge of generator stalling, the inverter has a feature called the Power Assistant. This feature is designed to seamlessly assist you in managing your caravan’s power supply, particularly during times of high demand.

Here’s how it works:

  1. The system has a default AC input setting at 15A, which means it allow the system to draw maximum 15Amp from the shore power/generator
  2. When you use the generator, you need to adjust this setting below your generator capacity if you want to use the power assistance feature without stalling the generator
    • For example, you have a 3000KVA generator, it may give you maximum 12amp. When you use more than 12amp, the generator will stall.
    • by setting the AC input to 11amp or lower, it will allow the system to draw maximum 11amp from the generator which will prevent the generator from the stalling
    • If you use more than 11 amp in the van, say 20amp, the system will only draw 11amp from the generator, and inverter will step in to assist the rest of amp by using the battery power.

[TBB] How to Change the AC Input?

***Always change the setting with cautious, the Default Setting for AC input is 15Amp, do NOT change exceed 15amp***

The Parameter you need to change is the AC input xxx A, the default setting is 15Amp

📘 [TBB Power] Digital Multi Control Monitor (Legacy)