Containerised Battery Bank

In a word…No.


All of these feel good initiatives are dreamed up by public relations arms of these corporations to have a “green” message when challenged on what they are doing to combat climate change.

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I appreciate the input from several of you regarding how this battery is to be charged, and converting waste heat or other energy to electricity to be stored in the battery seems an excellent idea, albeit somewhat trivial in the big picture of powering the vessel.
It strikes me that none of the folks peddling batteries (in both land- and sea-based applications) seems to be even slightly interested in discussing the lifetime costs (both financial and environmental) of the things - as we all know, batteries are:
a) not forever - they wear out and must be replaced/remanufactured at some point;
b) consist of some quantity (usually large) of heavy metals, which are generally, if not universally toxic; and
c) have significant potential for “unplanned” energy release (see the Norwegian ferry story of a few weeks ago).

All of these things bear on the lifetime costs, and need to be included in any analysis - all the nice fluffy “eco-friendly” words to the contrary.


Maybe, on the other hand nobody knows exactly what technological path will prove to be the most viable in the future. Maersk is a big company, it might be a smart strategy to have some in house expertise in various potential possibilities.

Actually installing this system on a ship is going to give Maersk some expertise in battery technology all the way from CEO to ship’s crew.


Running a MAN 60MC with RPM from 0-99 I get more steam at 70-75 than I do at ~85. The lack of scav pressure (the blowers cycle off on pressure around 83) means I get 400 C exhaust temps at the 70 RPM range.

As soon as the boost picks up my steam pressure falls off a bit, following the exhaust temperature.

I keep steam pressure, JW in/out, RPM, scav temp, and mean exhaust temp pulled up on a trend during maneuvering/run up/slow down.

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On a RORO with the ability to start cargo fans from the ECR, we used them to load up the generators a little during maneuvering. On the ship without the ability to start cargo fans from the ECR we ran our 1100 KW generators at 200 KW… Would be nice to have the ability to load them up and save the power for something else.

I hate idling 3 generators, that get pushed up to 60% for a few seconds (bow thruster) while the deck dept figures out how to tie up.

Nothing to do with powering the vessel on batteries alone. Just making better use of our equipment hours and maintenance.

It has not yet got to where battery banks installed on large container ships and RoRos are common. Where it is presently being used is on offshore vessels and short haul vessels, like ferries etc. where it makes a lot more sense.
Maersk is trying out many different options and not to score PR points, but because it makes good business sense.
If that scores some browny points along the way so much the better.

Ah, that. I wonder how this would look at full scale?

I’m thinking those guys need to go to firefighting school… But a good illustration of how stored energy can go sideways sometimes.
Maybe this is why Maersk thinks putting the battery in a container is a good idea? So you can eject the whole thing if needed?

Hmmm… lithium / water explosion at depth right next to the hull side? Sounds like a good way to sink the ship… What you saw in that video was a few pounds of batteries going up. If a 40 footer full of the things decides to go off, I think all the king’s horses and all the king’s men could pretty much forget about it.

Containerization just makes a lot of sense from the logistical perspective, from manufacturing this thing, moving it around, lifting it on board, securing it in place, storing replacements, managing modularity, etc. With the right circuitry in the box, you could conceivably drop it in the stack with the rest and plug it right in a reefer bus. Pretty clever, to be honest.


Yes, you’re probably right - not something you want to dump in the ocean right next to you =8^O

I found this article that discusses the environmental cost of batteries - in their case, EV batteries, but essentially the same problem on a slightly smaller scale. Vice article

True. But current fossils fuel usage has none of these disadvantages?
Both fossil fuel use and battery technology will become more efficient with less energy waste once politics gets out of the way. Their are engineers that love to innovate and make things more efficient. Efficiency in any engineering endeavor is taught as a core tenant of the profession.

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Lessons learned from Foss’ experiences are worth reading:

It reads to me that battery assisted power is worthwhile during short term high demand (like mooring).
Their discovery of electro magnetic interference messing with smart charging seems significant. Other findings seem intuitive now, like keeping battery banks separate from everything else, keeping them cool, and accommodating potential fire and explosion.
I think the Campbell and the Dorothy Ann have been running fine.

The report clearly confuses cells and batteries, as the largest cell that Kokam (Kokum is a misspelling) show on their website has 240 amp-hours capacity at presumably around 3.7 VDC, giving about 900 watt-hours. There is no way that Carol Ann is using enough individual cells in series to meet the energy/power demands as that would mean supply voltages of many kilovolts DC.

Kokam’s in-house marine batteries are water cooled 74VDC, 10.3kWh. each using two series strings of twenty cells of 70 amp-hours each.

That particular cell doesn’t seem to correspond exactly with any of their listed ones (optimized differently via differing chemistry) but should weigh between 1.1 and 1.9 kg with dimensions between 226x2275x12.3 mm and 268x265x13.7 mm. The cells are of pouch construction, broadly similar to the Polapulse flat carbon-zinc batteries that Polaroid built into film packs for their electrically operated cameras.

So two sets of fourteen Kokam batteries in series in the Dorothy Ann means they’re running the system at one kilovolt output which seems more reasonable. That would give a total capacity of both strings of about 390 horsepower hours at quoted capacity and neglecting losses.

Obviously if the contractors were assembling their own batteries the numbers would be different. 400 hp-hours seems small to me so I imagine that was the case. But my point is that any practical system using Kokam cells will have many many cells in parallel, even if the batteries were all connected in series.

Incidentally Kokam say that one of their cell types could put five megawatt-hours into a forty foot trailer, and another one three MWh.

Just noticed this reply… No, fossil fuels do not have these factors, at least not to the same degree.
a) not forever - nothing is “forever”, but modern internal-combustion engines last a very long time - and when they finally wear out, recycling iron and steel is a very efficient process.
b) internal combustion engines and fuel storage systems use primarily iron and steel, with almost no heavy (toxic) metals. Unlike wind-power systems, they also do not produce large quantities of waste fiberglass composites.
c) The hazards of “unplanned energy release” certainly apply to fossil fuels! This is one area where more experience will definitely yield rewards in battery technology.

Innovation is a wonderful thing, but concealing the true costs of ANY proposed new technology doesn’t do anyone any favors. Only by knowing the true costs can we make informed decisions about the viability (or lack thereof) regarding these things.

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They sure do, in spades. The energy density of liquid fuels is astonishing. But they don’t typically ignite simply by being exposed to air, and once ignited you’re not looking at a class D fire. And they’re not normally the distance of an ever-thinner (as we ramp up energy density) plastic membrane from disaster, and they don’t go into thermal runaway much (although putting gasoline in an alcohol pressure stove is a classic example).

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I wonder how they’re gonna split the bus…

Don’t you just tap the VFD at the DC stage?

I am really late to this party, but part of my company is in the battery energy storage business. If we leave the issues related to raw materials, and safety, aside (not trying to minimize those issues) it is absolutely true that batteries must be charged from an energy source, and then discharged, and there is a round trip efficiency loss, which can be 10-15% depending on many variables. So there are a couple of things which make batteries still worth while. Charging them from low cost energy, like surplus wind and solar power which would otherwise be dumped, or for example on a ship, since you probably don’t have wind or solar power…charging them when your generators are running at or near full load, which is probably their most efficient operating point, and then using them when maneuvering or some other operating point which would involve running your generators at low load where they will be significantly less efficient, i.e. consuming more fuel per kWh generated.

Some metrics. Today’s highest capacity containerized batteries can hold up to about 6 MWh (6000 kWh) in a 40 foot box. That’s as much energy as running a 1000 kW generator for 6 hours, or a 6000 kW generator for 1 hour. Not going to get your ship across a big stretch of water, but a still significant amount of energy. Power can be delivered instantly, if it matters, no ramp time waiting for turbos to spool. Above, Mr. Klaveness mentioned the energy density of diesel fuel as 230 g/kWh. That’s not correct. That is more than likely the measure of the fuel consumption of some diesel engine somewhere. A round number for the energy density of diesel fuel is 18,360 BTU/lb, or 42.7 MJ/kg. An older diesel engine might consume 230 grams of diesel to produce 1 kWh of shaft or electric power, modern ones are more like 180 g/kWh or less.

Ships are actually a very efficient way of transporting cargo, albeit often with highly polluting bunker fuel. But now with the push to low sulfur fuel, and further on to LNG, there will be less pollution produced per ton-mile or container mile or container km… I could go on for hours, but I’ll stop here.


One one vessel I was master of had a shaft generator. When manoeuvring both DG’s ran ship services and the shaft generator ran the bow thruster. At sea if the reefer load was less than 50% of capacity the total ship’s load was carried on the shaft generator. The emergency generator had the capacity to carry the hotel load of the ship and was used during maintenance in port making for a quiet engine room. Engineers once onboard very quickly placed their slippers under the bunk and showed no desire to move anywhere else.

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