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Designing a Portable Battery Energy Storage System for EV Charging
Main TrackRenewable EnergyST Engineering
Up to S$30,000 in POC / pilot fundingUp to S$30,000 POC Development Grant
ST Engineering
is a global technology, defence and engineering group with a diverse portfolio of businesses across the aerospace, smart city, defence and public security segments. Its commercial aerospace business is a world-class OEM and MRO solutions provider and is among the world’s largest third-party aircraft MRO service providers.
ST Engineering Commercial Aerospace is progressively transitioning its fleet of over 60 diesel trucks and vans to electric vehicles (EVs) as part of its sustainability and electrification roadmap.
However, the company’s hangar power infrastructure is limited, allowing installation of only 3 to 4 fixed AC charging points. This is insufficient to support a full EV fleet. Moving vehicles to off-site public chargers is operationally costly and time-consuming, causing unnecessary downtime.
To address this, ST Engineering is exploring a portable Battery Energy Storage System (BESS) capable of providing on-demand EV charging to supplement fixed charging points. The portable BESS would be charged indoors using a standard wall socket, then wheeled to parked EVs for on-site charging, enabling one-person operation.
A fully charged EV in the current fleet typically provides a range of about 400 km, lasting 2 to 3 days depending on delivery schedules and business volume. Not every vehicle requires daily charging, and a portable charger serving 20 vehicles/day (combined with 3 to 4 fixed chargers) is expected to meet operational needs.
ST Engineering is also open to alternative solutions beyond portable BESS, provided they achieve the same outcome: flexible, on-demand charging without infrastructure expansion.
How might we design and construct a portable Battery Energy Storage System (BESS) that enables on-demand, flexible EV charging for fleet vehicles?
Requirements
Technical Requirements:
- Must be portable and operable by one person.
- Must be designed for indoor charging from a standard 3-pin AC wall socket, then transported to charge parked EVs.
- Must support single-phase or three-phase 220 VAC charging.
- Target weight: ~60 kg (indicative, not a hard constraint)
- Indicative size: 560 × 320 × 600mm. You may counter-propose optimised dimensions.
- Must comply with Singapore Standard TR 25-3:2022 (EV Charging Systems) and IEC 62485-5:2020 safety standards, and use the AC Type 2 (IEC 62196-2) charging interface, the approved national standard in Singapore for both fleet and public EV charging to ensure compatibility and regulatory compliance.
- Must charge an EV from around 30% to 70-80% state-of-charge (SOC) within approximately 4 hours.
- Should allow charging safety, temperature control, and battery health monitoring features for long-term use.
- ST Engineering is evaluating EV models in the market, with battery capacity ranges from 45 to 80kWh. Therefore, the energy capacity requirement is 40 to 60 kWh per full charge.
Performance Requirements:
- Must demonstrate stable and safe charging performance that meets the 30-to-80% SOC in 4 hours benchmark defined under Technical Requirements above.
- Must maintain consistent charge-discharge efficiency and thermal stability across repeated cycles.
- Must verify one-person portability and usability, including wheeling and connection without assistance.
- Should support multi-vehicle use cases across daily charging cycles (approximately 20 vehicles/day shared between fixed and mobile chargers).
- Should include battery management and safety diagnostics to track performance over multiple charge cycles.
Who Should Apply:
- Minimum Technology Readiness Level (TRL) 6
Potential Sustainability Impact:
- Less need for costly power infrastructure upgrades and enables flexible on-site charging
- Support for ST Engineering’s transition away from diesel (and hence emissions reduction) by accelerating fleet electrification
- Better energy redistribution with reduction in grid demand peaks and cost savings with charging at night / off-peak
POC / Pilot & Incentives
Expected POC / Pilot & Timeline:
- Prototype development: Up to Q3 2026
- POC / pilot objectives: Validate mobility, one-person operation, and charging performance
- POC / pilot deployment: Begin with one portable unit alongside 3 to 4 fixed chargers; expand to 4 to 5 mobile units if pilot is successful
- POC / pilot location: ST Engineering’s hangar facility. More information on the site will be provided at the shortlisting and pitching stage.
- Future phase: Integration with fleet scheduling software and telemetry to optimise charger utilisation
POC / Pilot Funding:
- ST Engineering will provide milestone-based POC / pilot funding of up to S$30,000 for a prototype unit. Higher-cost proposals may be considered if justified by technical maturity or expanded scope.
- Enterprise Singapore is augmenting this support with a POC development grant of up to S$30,000 for eligible startups / SMEs. Foreign startups / SMEs may be considered if developmental activities are based in Singapore and only if a Singapore office is incorporated. The POC Development grant could also be awarded to startups / SMEs incorporated in Singapore for projects with overseas pilot deployment potential.
POC / Pilot Support:
- Access to EV fleet, charging area, and hangar facilities for prototype testing
- In-house engineering support
Further Opportunities:
- If successful, the solution can reduce the need for additional fixed EV chargers at ST Engineering’s facilities and enable mobile charging across multiple sites.
- In the longer term, the portable BESS or equivalent solution could become a commercial product line for use in logistics fleets, emergency roadside assistance, or remote sites without charging infrastructure.
Info Session
Check out the recording from our Info Session, where Lidl & Kaufland Asia shared more about their challenge statement.
RESOURCES
Info Session Recording
Revisit the detailed presentation on this challenge statement from our virtual Info Session.
Next Steps
Still have questions?
- Write to us at info@padang.co with any questions.
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