1000kWhr lipo pack !

[Hillhater]

Yea baby,.. now thats what i call a real pack ! :lol:
http://www.chargedevs.com/content/news-wire/post/rolls-royce-supply-azipull-propulsion-system-norway%E2%80%99s-electric-ferry-future

 

[SamTexas]

Its electric motors are powered by a 1,000 kWh lithium-polymer battery pack that weighs 10 metric tons.

Pathetic if the numbers are correct. That's 100Wh/kg.

 

[neptronix]

It's probably lifepo4 or some super duper long life ( at the expense of whr/kg ) 3.6-3.8v nominal cell.

A comic oversizing of a battery means that this thing could last prolly a decade.
Which is what you want for an application like this!

 

[Xrain]

It's probably lifepo4 or some super duper long life ( at the expense of whr/kg ) 3.6-3.8v nominal cell.

A comic oversizing of a battery means that this thing could last prolly a decade.
Which is what you want for an application like this!

That actually likely isn't much of a over-sizing at all. A ship that large likely would normally have a pair of 1200HP+ diesel engines. So it would require a set of ~1000 KW electric motors to replace them. So that boat likely cant travel much more than 30min to an hour or so.

Boats unlike cars are generally constant power, so they don't get many benefits from running electric motor. In a car you could get away with using a 40HP electric motor to replace a 250HP gas engine. In boats however its pretty much 1 to 1.
That mass number for the battery pack probably includes all of the battery management equipment, as well as the water proof cases they are likely stored in. So its probably not as bad of a kg per Wh as it appears.

I've looked into using batteries for large vessels before, I figured for a 100 ft. vessel to get one quarter the range as a similarly sized diesel powered boat has, I would need a ~432 MWh battery pack. considering the vessel has a gross weight of 250 tons, even at 400 wh/kg it still comes out to over 2000 tons of batteries.

I suppose the only answer would be to actually make the boat out of batteries... :lol: At least battery technology is practical enough now that it can be used for these short duration ferry crossings.