Electric cars have been in the spotlight for years. Now ships are going electric too. Not the little park boats – real cargo container ships and river ferries. The battery suppliers are the same familiar names: CATL, CALB, Sunwoda. They're competing hard at home, and now they're looking at Central Asia and Southeast Asia – the Caspian Sea, the Mekong River, thousands of islands. Diesel is expensive there, and emission rules are getting tighter.
Ships going electric means shoreside infrastructure has to keep up. Charging stations, shore power systems, distribution equipment – all of them need disconnect switches. High humidity and salt spray at ports are much harder on electrical gear than inland conditions. Pick the wrong disconnect switch, contacts overheat, operation gets stiff, and the charger won't work. Surge arresters are just as critical. Coastal areas and inland waterways get plenty of lightning strikes. Without good metal-oxide arresters in charging stations and ship distribution boxes, one lightning hit can knock out the whole charging setup. These seemingly small components are what make electric ship operations reliable.
The China Mobile Communications Association released data this March. The global marine battery market reached $887 million in 2025, more than double what it was two years ago. Still tiny compared to the auto market. What's really interesting isn't just the number – it's that battery makers are starting to go overseas, and they're not just selling cells anymore. They're selling complete systems.
Take CATL. Late last year they introduced an integrated "ship‑shore‑cloud" solution. Fancy name, but it just means the ship's batteries, the shore chargers, and the backend data all talk to each other. In March this year something significant happened: Shandong Xinneng Shipbuilding built a 182 TEU pure electric container vessel for CMA CGM, using CATL's batteries. That ship will run in Vietnam, from Binh Duong to Cai Mep port. It's the first Chinese-built all-electric inland container ship exported overseas – a milestone.
CALB took a different route – getting certified. They now have type approvals from China Classification Society, DNV, ABS, RINA, and Bureau Veritas. All of them. Getting that done early makes it much easier to enter the European market later. They also won the battery order for Saudi Aramco's first hybrid offshore support vessel (Karan 8) – a serious reference in the Middle East. Last week at the Asia Pacific Maritime exhibition in Singapore, they showed their "Zhiyuan" marine battery series, covering ferries, cargo ships, and offshore vessels. Wide coverage.
Sunwoda is a bit slower but catching up. Their 314Ah cell got CCS certification and started going onto yachts this year. In mid‑May at the Asia Yacht Expo, they launched their "SAIL" marine battery system, moving from just selling cells to selling complete systems. That's the right move – shipyards want turnkey solutions, not a pile of cells to assemble themselves.
In Central Asia, Kazakhstan is the place to watch. They're pushing the Trans‑Caspian International Transport Route (TITR) to bypass Russia for freight. Upgrading Caspian shipping means not just new vessels – the port equipment matters too: shore cranes, hoists, transfer vehicles all need electricity. CATL's ship‑shore‑cloud solution would be a great showcase if it lands in the Caspian. Along with it come disconnect switches and surge arresters for those port distribution cabinets.
Southeast Asia is even busier. Vietnam amended its Maritime and Inland Waterways Law in April this year, opening the door for foreign‑flagged green vessels. That CATL‑powered ship running in Vietnam is one sign that policy is loosening. But Vietnam has a catch: imported batteries need CR certification, one model per test, and the timeline is long. Anyone serious about the market should get several mainstream models certified ahead of time. Meanwhile, Vietnamese ports are expanding charging infrastructure, and demand for high‑voltage disconnect switches and composite‑housed surge arresters is already starting to appear.
Indonesia has thousands of islands. You can't build charging piles everywhere, so battery swapping makes sense. Make the battery the size of a container, hoist it off at the dock, drop a fresh one on – much faster than waiting for a recharge. Think Nio battery swap stations, but for ships. Those swap stations also need disconnect switches to isolate faulty circuits and surge arresters to protect against induced lightning.
Thailand's Laem Chabang port already has a fleet of electric terminal tractors. Ships aren't fully electric yet, but the port equipment is ahead of the vessels. Thai operator Seudamgo recently ordered electric hydrofoil ferries – a sign that Thailand is open to high‑end electric vessels. Port electrification brings electrical retrofits, including replacing old disconnect switches and adding surge arresters – and tenders are already appearing.
For Chinese exporters, a few things stand out. First, certification is the gatekeeper. Without classification society approvals, you don't even get a chance to quote. Second, don't just sell components – sell systems. Shipyards want turnkey packages with thermal management, fire suppression, and BMS all integrated. Third, Central Asia's Trans‑Caspian corridor might take off faster than Southeast Asia, because those are new projects without the baggage of old ship replacements. Fourth, don't focus only on batteries – disconnect switches and surge arresters are just as essential, and their margins aren't any lower than batteries.
Battery packs from Sunwoda, CALB and the others have moved past the "do they work" stage. The competition now is about who can make the whole system work smoothly. From Vietnam's inland waterways to the Caspian ferries, from Thai ports to the Indonesian archipelago, the anchor of China's battery supply chain has been dropped. Marine electrification penetration is still below 1%. The pond is big and there aren't many fishermen yet. Whoever solves battery stability in hot, salty, humid environments, whoever builds a workable battery‑swapping network, and whoever gets disconnect switches and surge arresters properly designed for port use – that's who will win the next round.