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Comment by ebbv | Hacker News Reader

The battery capacity is increasing by only 7.6% (from 17.1 KWh to 18.4 KWh) but they are claiming an increase electric only mode range of 51% (35 miles to 53 mlles.) I wonder where all the extra range is coming from.

My Leaf gets a claimed 80-90 mile range on its 24 KWh battery, so proportionally the 53 miles on 18.4 would make sense, but remember the Volt is carrying around an ICE and all its trappings (it foregoes the drivetrain for the ICE, but it still needs lubrication, cooling, intake, exhaust, etc.) so the volt weighs about 300 lbs more than the Leaf (which is ~10%), and that's going to have an efficiency cost.

Also, I should point out the leaf has had a 25% battery capacity increase in the new model, which should result in a direct 25% range increase since the new battery takes up the exact same space and weight as the old one.

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The Gen 2 Voltec drivetrain has two motor/generators, two planetary gearsets, an abundance of clutches and the ICE. This allows the system to be used in five distinct drive modes ( http://gm-volt.com/2015/02/20/gen-2-volt-transmission-operat... ). The all-electric range increase is proportionally greater than the battery capacity increase because the new drive system uses two-motor drive mode more often than the first gen drive system.

This is very fascinating, new mechanical approaches proliferate!

Koenigsegg has the total opposite approach in their hybrid Regera supercar: no gearboxes at all. Low speed high torque is delegated to the electric motors, and the internal combustion engine only engages after a certain speed.

http://jalopnik.com/how-the-1-500-hp-koenigsegg-regera-hits-...

I think that is a potentially fruitful approach.

They upgraded the range extender as well. Since it's more powerful it allows for the battery to be depleted further before it needs to definitely kick in which allows for a greater electric only range.

How did they pull that off? Is it a different battery chemistry?

I don't know for sure about the leaf, but if you look at the original Tesla battery it was created by combining a lot of smaller batteries which wastes a lot of space (double cell walls, more external connectors, etc).

Oh interesting... so by removing the walls and connectors, they could be net-neutral in mass. Makes sense.

My 2014 volt regularly gets 42 miles on battery only which would change your calculations a bit.

Where and at what speed do you usually drive? I don't get more than 35 miles on battery on my 2015 Volt, but most of my driving is on freeways in off-traffic hours.

Lots of short side street trips (groceries, hardware, parks) and a few longer trips (hiking nearby, weekwnd getaways, etc) but I only drive it on the weekends. I take transit to work. Highway driving is brutal on the battery (in a mileage capacity per charge...wind resistance and whatnot).

Does it even have a traditional exhaust? The engine makes such little noise when it's even using gas.

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