FFE Liquid Cooling vs VW eGolf Air Cooling

[Northface]

Hi, I'm new to the FFE discussions and am working on purchasing a 2017 and would like to understand the pro's and cons of liquid cooling vs air cooling like the VW eGolf uses. I live in Ottawa and our winters are long and on the cold side. What would work best in this kind of climate?

rgds

 

[Omen87]

The FFE uses a liquid active cooling sytem. If it is cold outside and your car is plugged it it will heat and circulate the coolant around the battery to keep the battery at a more appropriate temperature. And vice versa if it is very hot it will circulate coolant to try and pull some heat away from the battery to keep it happy. The cold doesn't really damage the battery, but it is much less efficient when it is cold so you will see less range even if you were to not use the cabin heater.

 

[triangles]

Cold in and of itself will not harm a lithium ion battery. Charging a lithium ion battery in sub zero temps (Celsius) however can cause permanent battery damage. I am going to go out on a limb and assume the VW has battery heaters that warm the battery before charging. While I don't know under what conditions it happens, I do know the FFE's battery thermal management heats the battery when it's cold out. I'm would hope both Ford and VW are smart enough to warm the battery before allowing it to charge in sub zero temperatures.

Since you are not in a hot climate there isn't any advantage to the FFE's battery thermal management unless you plan to DC fast charge (L3). This is because heat can be very bad for a lithium ion battery. I don't pretend to understand how, I just know that above a certain temperature the hotter a battery gets the more damage it incurs. L3 charging produces a lot of heat in the battery. Again I am speculating but I would think VW would monitor battery temp and slow down the L3 charging as the battery heats up. Wait I am assuming the VW has L3 charging capabilities...

 

[EVA]

Maybe VW is smarter than Nissan, or learned the lesson on how to manage lithium ion batteries without active temperature management. Somehow I doubt that sincerely.

BMW, Tesla, and Ford all opted to use active temperature management for their batteries. Nissan used air cooling. The first generation of Leaf had a horrible battery degradation problem. Nissan may have solved the problem. But honestly - the biggest electric car manufacturer and two other use active management. Nobody ever talks about battery degradation in a Tesla. There is some talk about some level of degradation here (although my personal experience, it doesn't exist). But everybody talks about it chez Nissan.

Your call - hitch a ride to air cooling. I'd probably pass on that.

You'll still end up with heat in the summer - you have days in the 80 or 90s. That's enough to activate active cooling while charging.

 

[michael]

It's not only the overall temperature but also the possibility of local hotspots in the pack. Liquid is better.

 

[tinilk]

Again I am speculating but I would think VW would monitor battery temp and slow down the L3 charging as the battery heats up. Wait I am assuming the VW has L3 charging capabilities...

My friend has a new eGolf and he says it won't allow you to L3 charge more than twice in a row. When he takes a long-ish trip that requires 3 charging stops, he has to charge on L2 for one of them.

Personally, I would think even two consecutive L3 charge stops would leave the battery very hot and cause some degradation, even in winter temperatures.