Coolant

[garypen]

I couldn't help but notice the coolant reservoir and radiator.
What exactly is liquid-cooled in the e-Golf?

I know they were toying with the idea of cooling the batteries, but decided against it.
Does the motor get hot enough from friction to require it?
Or, is it one of the electronic components?

 

[HabemusQuattro]

Yes the coolant is for the electric motor. Conversion of electrical power to motive power isn't lossless so there is still some heat generated.

On models without a heat pump the coolant is also used to provide heat to the passenger space. That's why heat pump models specify 5.3 liters of coolant and non-heat pump models specify 5.5 liters of coolant.

 

[garypen]

Interesting. I wouldn't have thought enough heat was generated to require water-cooling.

After all, VW went for many years with an air-cooled ICE. Plus, most motorcycles, also ICE obviously, are air-cooled.

I wonder why they didn't extend the water-cooling to the batteries, as long as there was already a coolant system in the car?

 

[RonDawg]

If VW followed Nissan's blueprint for EVs (and in regards to the lack of liquid cooling for the batteries, they certainly did), this is what you can expect to be liquid cooled on the eGolf. From: http://www.electricvehiclewiki.com/Drivetrain

The LEAF has a cooling system. Its coolant capacity is 7 quarts. The following components are liquid cooled: on-board charger, DC-DC converter, motor's inverter, and motor. Cooling flows through those components, in that order, before arriving back at the radiator. Two electric pumps in series pump coolant from the radiator past the coolant reservoir, into the pumps, then back out to the on-board charger.

I wonder why they didn't extend the water-cooling to the batteries, as long as there was already a coolant system in the car?

Many Leaf owners, especially those in very hot environments like Phoenix, Las Vegas, etc. are asking why Nissan didn't do the same thing. The reason is simple: cost. They may have only saved a few dollars by leaving it out, but across thousands of cars it becomes significant.

Also in those cost savings are simpler (and thus cheaper) assembly, and in theory one less component to have to be warrantied. The latter though was offset by Nissan having to retroactively provide a battery capacity degradation warranty after many outraged early adopters (and a few lawsuits), which didn't exist prior to MY2013.

 

[garypen]

That's all very interesting. Hopefully, living in a relatively moderate climate, there won't be much of an issue with an air-cooled battery. OTOH, it does get pretty hot on occasion during the summer, as witnessed by a few days in just the last week or two.

These sorts of issues really reinforce the argument of leasing vs buying for these vehicles that use technology that is in such early stages of development.

 

[normf3]

That's all very interesting. Hopefully, living in a relatively moderate climate, there won't be much of an issue with an air-cooled battery. OTOH, it does get pretty hot on occasion during the summer, as witnessed by a few days in just the last week or two.

These sorts of issues really reinforce the argument of leasing vs buying for these vehicles that use technology that is in such early stages of development.

True, though the niceness of the e-Golf makes it tempting to want to hang onto it. I have the option to buy it anywhere along the line. Which brings up the issues of how much of the battery capacity will be gone after 3 years and the resale value of electric cars with used batteries. [You may be able to bargain with the dealer on the purchase price at the end of the lease, considering the drop in value of electric cars] It would be nice if batteries could be replaced in the future for a semi-reasonable cost.