Bidirectional EV Charging with the Sigenergy SigenStor: A Complete Guide

You’ve got solar, you’re eyeing a battery, and your EV is the biggest “battery” you own — but using it to power your home still feels murky. Is bidirectional charging real yet in Australia? What even is it? Will it work with your car? And is a DC charger worth the price compared to a standard wall box, especially with tariffs shifting and evening usage hurting your bill? (NSW’s rising prices and modest feed‑in credits are pushing more households toward self‑consumption.)

In this guide, you’ll get a walkthrough of Sigenergy’s SigenStor DC bidirectional charger — how it fits into a SigenStor solar‑plus‑battery system, what it can and can’t do today, what it costs to install, and which EVs in Australia have been tested.

What is bidirectional EV charging?

The simple version: most chargers only push energy into your EV. Bidirectional charging lets energy also flow out of the EV when you want it.

• V2H (Vehicle‑to‑Home): your EV helps run your home — for bill savings at night or for backup during outages.
  
• V2G (Vehicle‑to‑Grid): your EV exports to the grid (or a retailer/VPP) when prices are attractive.
  
• V2L (Vehicle‑to‑Load): a socket to power tools/appliances directly from the car (handy, but separate from whole‑home support).
  
• V2X: umbrella term covering the above (home, grid, building, loads).

Why DC matters:

• AC chargers rely on the EV’s onboard inverter. They’re common (7–22 kW), cheaper, and one‑way in most homes.
  
• DC chargers use an external power module to convert power. Sigenergy’s SigenStor module is DC and bi‑directional, so it can charge fast and discharge from the EV back to the home/grid (V2X) when supported by the car and the system. That’s how you unlock meaningful V2H/V2G.

Why Australians care in 2025:

• Evening grid prices are the sting in the bill, while daytime solar exports are worth less. Using your own solar later — either from a home battery or your EV — boosts self‑consumption and cushions price spikes.

How the Sigenergy SigenStor DC EV Charger Works

The Sigenergy SigenStor DC EV charger isn’t a standalone wall box — it’s an add-on module that works as part of the SigenStor solar-plus-battery system. That integration is what enables its bidirectional capability and high charging speeds.

Direct DC-to-DC Connection

Most home EV chargers are AC chargers, which feed power into your car through its onboard inverter. This means the car controls charging speed and efficiency. The SigenStor charger, however, uses a DC-to-DC link between your home battery/solar system and your EV’s battery.

• Result: Less conversion loss, higher efficiency, and faster charge/discharge rates.
  
• Speeds:
  
  • 12.5 kW model → adds roughly 75 km of range per hour.
    
  • 25 kW model → adds roughly 150 km of range per hour (actual figures depend on the car’s efficiency and charging curve).
    

Bidirectional Power Flow

The charger can send power to the EV (charging) and from the EV (discharging). This supports:

• V2H (Vehicle-to-Home) — powering household loads from your EV battery during the evening or a blackout.
  
• V2G (Vehicle-to-Grid) — exporting power to the grid when tariffs are high (if supported by your retailer or a VPP program).
  
• PV surplus charging — prioritising charging from excess solar generation.
  

Integration with SigenStor Energy Management

As it’s built for the SigenStor ecosystem, the charger works with Sigenergy’s AI-driven energy management platform:

• Automatically decides when to charge or discharge based on tariff schedules, solar production, and household demand.
  
• Allows manual control via the Sigenergy app for instant override.
  
• Can coordinate with the home battery so you decide whether energy sits in the car, in the stationary battery, or both.
  

Safety and Standards

The DC charger uses the CCS2 (Combined Charging System) standard — the same connector found on most modern EVs in Australia — and includes:

• IP65 weather resistance for outdoor installation.
  
• Overvoltage, overcurrent, and temperature protections.
  
• Emergency stop and isolation features for maintenance.

Key Specs & Features

Models: 12.5 kW and 25 kW

Rated Power:

• 12.5 kW → up to 12,500 W DC output/input (~75 km range/hour)
  
• 25 kW → up to 25,000 W DC output/input (~150 km range/hour)
  (Speeds vary by EV efficiency and charging curve.)

Voltage Range: 150–1000 V DC

Max Current: 35 A (12.5 kW) / 70 A (25 kW)

Connector: CCS2, 10 m cable

Bidirectional functions: V2H, V2G, PV surplus charging

Smart features: App-based control, programmable schedules, AI-optimised charging

Build: IP65 weather rating, forced air cooling, operating range -20 °C to +55 °C

Safety: Overvoltage, overcurrent, temperature protection, emergency stop

Installation Notes

• Only works as part of a SigenStor system (cannot be installed as a completely standalone charger).
  
• Can be mounted indoors or outdoors, wall or pedestal-mounted.

Vehicle Compatibility in Australia (2025)

While bidirectional charging is an exciting concept, it’s only useful if your EV supports it. As of August 2025, Sigenergy has confirmed and tested a short but growing list of compatible EV models in Australia.

Currently Tested & Confirmed Models

From Sigenergy’s own compatibility testing:

• Volvo C40 Recharge
  
• BYD Atto 3
  
• Ford F-150 Lightning

These models are confirmed to work with the SigenStor DC charger for both charging and discharging (V2H/V2G), provided the firmware on the vehicle is updated to the tested version or newer.

Future Compatibility

Sigenergy is actively expanding the list of supported models as more EV makers enable bidirectional functionality. Popular models expected to be tested in the next 12–18 months include:

• Hyundai Ioniq 5 / Ioniq 6
  
• Kia EV6
  
• Nissan Leaf (latest models with CHAdeMO → CCS2 adapters pending approval)

If you’re considering this charger, it’s important to confirm compatibility with your EV dealer or installer before purchase — especially if your car is not on the official tested list.

Installation and Pricing

The Sigenergy DC EV charger is not a cheap plug-and-play unit — it’s a high-power, bidirectional module that needs to be integrated into your existing or new SigenStor system by a qualified installer.

Pricing (Including Installation)

Model & Install Timing	Price (AUD, incl. GST)
12.5 kW — Installed same day as solar/BESS	$6,644.22
12.5 kW — Separate visit	$7,222.38
25 kW — Installed same day as solar/BESS	$8,396.62
25 kW — Separate visit	$8,974.78

Notes:

• Prices include the 10 m CCS2 charging cable.
  
• “Same day” install means the charger is fitted at the same time as your SigenStor battery or solar system, saving on labour and travel costs.
  
• “Separate visit” pricing reflects the extra time and labour to retrofit the charger later.

Installation Requirements

• Must be part of a SigenStor system.
  
• Installed by a Clean Energy Council-accredited installer.
  
• Suitable for indoor/outdoor mounting.

Pros and Cons

Like any emerging technology, the Sigenergy SigenStor DC EV Charger has clear strengths — but also some limitations you should be aware of before investing.

Pros

• Fast DC Charging at Home
  With up to 25 kW charging power, it’s significantly faster than most residential AC wall boxes (typically 7–11 kW). This means shorter top-up times and greater flexibility.
• True Bidirectional Capability
  Supports V2H (Vehicle-to-Home) and V2G (Vehicle-to-Grid), so your EV can act as a large home battery or even earn income from exporting to the grid if your retailer offers a program.
• High Efficiency
  Direct DC-to-DC transfer avoids double conversion losses, achieving efficiency above 97%, which means less wasted energy and lower charging costs.
• Seamless Integration with Solar & Battery
  Works natively with the SigenStor system, allowing intelligent energy management and easy switching between EV, home battery, and household loads.
• Future-Proof Design
  Supports the CCS2 standard and is built to handle the ISO 15118-20 bidirectional protocol, which more EV makers are adopting.

Cons

• Limited Compatibility Today
  As of 2025, only a few EV models in Australia are officially supported (Volvo C40, BYD Atto 3, Ford F-150 Lightning). If your car isn’t on the list, you can’t use V2H/V2G yet.
• High Upfront Cost
  $6,600–$9,000 installed is a big investment, especially if your EV can’t yet take advantage of bidirectional functions.
• Requires Full SigenStor System
  You can’t install this charger as a standalone product — it must be paired with a SigenStor battery/inverter setup, which adds cost and complexity.
• New Technology Risks
  Bidirectional charging standards are still maturing, and firmware updates (both from Sigenergy and car manufacturers) may be needed for full functionality.

How It Compares

High-power home EV charging is still a niche market in Australia — and true bidirectional options are even rarer. Here’s how the SigenStor DC charger stacks up against other contenders.

Compared to Typical AC Wall Boxes

• Power Output: Many home AC chargers deliver 7 kW (single-phase) or up to 22 kW (three-phase). While these can be quick, the SigenStor’s 12.5 kW and 25 kW direct DC output bypasses the EV’s onboard inverter for higher real-world efficiency and sustained high-speed charging — particularly valuable for large-battery EVs.
  
• Bidirectional Capability: AC units are usually one-way. Even the few AC bidirectional chargers (like the Wallbox Quasar 2) are limited in Australia due to compatibility and certification hurdles.
  
• Efficiency: DC avoids the EV’s onboard inverter, reducing losses.
  

Compared to Other DC Home Chargers

• Wallbox Quasar 2 (DC, bidirectional): Not yet widely available in Australia, limited to 7.4 kW, CHAdeMO and CCS2 in some markets — but at lower power than the Sigenergy.
  
• FIMER & Delta DC Chargers: Offer high-speed DC charging (10–25 kW), but typically lack residential bidirectional capability in Australia.
  
• Cost: Sigenergy pricing ($6.6k–$9k installed) is competitive with other high-end DC home chargers, though the SigenStor requirement adds a system cost layer.
  

Why It Stands Out

• Integration: The SigenStor module is part of a complete solar + battery ecosystem, enabling smooth energy management without third-party controllers.
  
• Higher Power: 25 kW is among the fastest home-capable DC chargers on the market.
  
• Bidirectional with CCS2: Future-ready for the standard most new EVs in Australia are adopting.
  

Where Others Might Be Better

• If you don’t have (or plan to have) a SigenStor system, a standalone AC or DC charger from brands like Fronius, Delta, or Tesla may be more cost-effective.
  
• If you own a CHAdeMO vehicle (e.g., older Nissan Leaf), specialised CHAdeMO bidirectional chargers are more suitable — though their future in Australia is uncertain.

Is It Worth It?

Whether the Sigenergy SigenStor DC EV charger is a smart buy for you depends on your EV, your energy setup, and your goals.

It Makes Sense If:

• You already own (or plan to buy) a compatible EV like the Volvo C40, BYD Atto 3, or Ford F-150 Lightning — and want to use it for V2H or V2G now.
  
• You’re installing a SigenStor solar + battery system and want fast, efficient EV charging built into your energy ecosystem.
  
• You have high evening power use or want blackout resilience without buying an oversized stationary battery.
  
• You’re in a state with battery rebates or VPP incentives, which help offset the cost.
  
• You value future-proofing — knowing more EV models will support bidirectional charging in the coming years.
  

You Might Wait If:

• Your EV isn’t yet compatible — you’d be paying for features you can’t use.
  
• You don’t plan to install the full SigenStor system.
  
• Your driving patterns mean you’re rarely home during the day to charge from solar, limiting V2H/V2G benefits.
  
• You’re waiting for more competition in the home bidirectional market, which could push prices down.

The SigenStor DC charger is one of the fastest and most capable bidirectional home chargers available in Australia, however its value hinges on having the right EV and the SigenStor ecosystem in place. If you tick those boxes, it can significantly boost your energy independence and make your EV a genuine part of your home’s energy strategy. If not, you may be better served by a standard AC charger for now — and revisit bidirectional options when compatibility and incentives improve.