Overview
Mobile energy storage charging packages a battery, DC chargers and a control system onto a trailer, container skid or self-propelled chassis. Because the unit carries its own energy, it needs no grid connection at the point of use - it can be towed to an event, a construction site, a stranded vehicle or an overloaded fixed hub. Between deployments it recharges from a conventional socket or a depot charger, so the electrical infrastructure requirement moves to wherever it is cheapest and easiest.
How it works
The unit consists of a battery pack (commonly LFP for cycle life and safety), a DC/DC output stage feeding one or more CCS guns, an AC output for tools or events, and a telematics controller with OCPP support for authentication and billing. Typical configurations range from a 100-400 kWh trailer with 180 kW DC output to a 1.49 MWh container with two 360 kW four-gun charge posts. Recharging can be done at 0.2-0.5 C to protect cycle life, meaning a 200 kWh unit refills in roughly 2-5 hours.
Advantages
- Zero site electrical works required before deployment
- Deployable in minutes or hours, not months
- Relocatable as demand patterns change
- Ideal for events, fleets and emergency roadside charging
- Fills gaps in fixed networks during construction or outages
- Can double as a mobile power source for tools and equipment
Considerations
- Energy limited by onboard battery, not by grid availability
- Requires transport, towing or driving logistics
- High cost per delivered kWh compared with fixed charging
- Battery occupies most of the unit mass, reducing payload options
- Weather and road exposure accelerate wear
- Regulatory treatment of mobile charging varies by jurisdiction
Applications
- Roadside assistance and emergency charging
- Construction and infrastructure sites
- Events, festivals and temporary venues
- Fleet overflow and overflow depots
- Disaster relief and grid-outage response
- Vehicle testing and logistics yards
Cost breakdown
For a mobile unit the battery typically accounts for 45-60% of cost, the DC charging and conversion hardware 20-25%, the trailer or chassis 10-15%, and controls, telematics and branding the remainder. Because purchase volume is low relative to fixed equipment, mobile units carry a cost premium per kWh delivered that is offset by avoided site works.
Market outlook
Mobile charging is a fast-growing accessory to the fixed charging network rather than a replacement for it. Chinese and European suppliers now offer standardised 100-400 kWh trailers and 1.5 MWh four-gun container systems at catalogue prices, and the segment benefits directly from declining LFP pack prices. Deployment is strongest where grid reinforcement lead times exceed 12 months.