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Old 05-24-2018, 02:49 AM   #32 (permalink)
Isaac Zackary
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Originally Posted by vskid3 View Post
Has anyone added better thermal management to the battery pack? I looked into it a bit in the past but didn't find anything.
Not that I know of.

Existing TMS
From what I understand the existing "thermal management" works like this. On 2011 and 2012 cars a battery heater is optional, and on all 2013 and later cars this battery heater is a standard feature. When extremely cold the battery heater uses some 300 watts, but only to keep the battery from being damaged from freezing. I've noticed in the bitter cold that my Leaf has terrible performance and range in spite of having a battery heater. The winter package also comes with a thin wrap of insulation around the battery.

For cooling the battery there is a space above and below it that air passes through as the car drives down the road. Some of the car's climate control also exhausts on the battery. This has been noticed because the battery will slightly cool if you use the AC and slightly heat if you use the heater. However, the cooling and heating effects are minimal. You can get better results by simply parking in or out of the shade.

TMS ideas
  1. One idea would be to just blow more air around the battery. There is some space behind the motor and controller where some blowers could be installed and blow more air around the battery. Of course this will only help bring battery temperatures closer to ambient, but that's better than nothing.
  2. Another idea would be to do the above but with some sort of water spray for cooling. Or cool the air some other way.
  3. A third idea would be to apply cooled seat technology to the battery. The battery is one big box. But if wrapped in some sort of tubing then cooled (or even heated) coolant could be pumped around the battery.
  4. The best TMS idea would be to redesign the whole battery. The battery has enough space to hold some 72kWh of electricity if you replace the Leaf's modules with the right cells (like LG MJ1 18650 cells). Even replacing the Leaf modules with Tesla/Panasonic cells you'd get some 50kWh. Since most other cells are cylindrical (like 18650's) that leaves space between them for tubing. Of course this would not be the kind of project for the faint of heart.
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