37.7 tonnes each. Now in Karachi.

01 / FIELD NOTES

Container-shaped. Not a conventional container shipment.

I handled two 20HQ energy storage units from Shanghai port to Karachi port. Each unit had 4.18MWh capacity and an actual shipping gross mass of 37.7 tonnes, including the enclosure. Shipped as a pair under UN3536, both have now arrived.

A request for “two twenty-foot containers to Karachi” would leave out the facts that shape this job. This is both a dangerous goods movement and a heavy-equipment movement: unit condition, mass, stowage and terminal handling all matter.

For a shipper or an overseas forwarding partner, the useful lesson is not simply that these units moved. It is why the origin-side discussion needs someone who considers the DG documentation and the physical operating conditions together.

03 / FIELD NOTES

Why discuss paired shipment early?

These two 20HQ units were shipped as a pair. For a similar project, establish whether pairing is required, whether a single unit is acceptable and how unit weights affect the proposed stowage arrangement before finalising dispatch quantities.

Two twenty-foot units do not automatically secure a usable forty-foot position. The actual vessel, unit type, weights and stowage review still matter. Paired shipment also does not mean simultaneous lifting; stowage and lifting arrangements need separate confirmation.

There is no claim here that every carrier requires an even number. Odd quantities and split delivery schedules are reasons to ask early, not reasons to assume rejection.

04 / FIELD NOTES

“Can it be lifted?” is only the first question.

A single mass threshold does not decide the route. The enclosure’s permitted gross mass, actual shipping mass, road arrangements, origin-terminal handling method, vessel stowage and any transshipment or discharge terminal must be considered.

SIPG’s public operating guide includes an energy-storage-container entry application and instructs applicants to confirm the handling method with the terminal first. An ordinary heavy-container routine is not sufficient evidence for a BESS movement.

Units approaching 45 tonnes or beyond deserve early project-specific assessment. That figure is not presented as a Shanghai-wide limit, nor as proof that lighter units will be accepted. One crane’s rated capacity is not approval for the full transport chain.

05 / FIELD NOTES

Origin handling is only part of route acceptance.

“Karachi” alone does not identify every operational condition. Confirm the actual discharge terminal, heavy-unit handling arrangements and carrier acceptance for the proposed route. Include intermediate terminals if transshipment is involved.

This is why an early conversation is useful: discharge conditions can be considered while equipment quantities and dispatch plans still have room to change, rather than becoming a late question after the cargo is ready.

06 / EQUIPMENT REFERENCE

Does 5MWh mean 42 tonnes?

Some specific products are in that range. Sungrow’s cited 2024 PowerTitan 2.0 datasheet lists 5.015MWh configurations at 42 and 42.5 tonnes. CATL has also presented a 6.25MWh TENER system in a twenty-foot container.

These examples are not a market-share ranking, a capacity-to-weight formula or shipping limits. Battery, enclosure, thermal-management and power-conversion configurations can differ. A manufacturer’s product weight must be reconciled with the actual shipping configuration before declaration.