Hybrid Heat: HVAC and Battery Life

One of the aspects that many first-time hybrid car owners tend to overlook, is the correlation between the car’s AC system, the health of the battery, and regular servicing of the hybrid car. Hybrid cars will not be able to take full advantage of a battery if it is not properly maintained at the correct temperature.

Lithium Batteries

Lithium batteries and its derivates are batteries that work best between -10 degrees celsius and 30 degrees celsius. This is between 14 degrees Fahrenheit and 86 degrees Fahrenheit. Anything below -10 degrees celsius will adversely affect lithium batteries, not allowing it to achieve it’s full rated power until the cells in the battery warm-up. This effect can be detrimental to battery electric vehicles, especially when compared to plug-in hybrids. Plug-in hybrids can use gasoline as a backup as the lithium cells warm up to its full potential. However, batteries that are consistently exposed to hot temperatures lose their ability to store energy altogether. Over time, this can permanently damage the battery, especially if the battery reaches more than 110 degrees Fahrenheit.

This Is Where The AC System Comes In

To help combat extreme temperature fluctuations, the AC system in the hybrid car needs to work properly. Many manufacturers use air-cooling or liquid-cooling systems to power the car’s AC system. There are unique benefits and cons to both.

  • Liquid cooling. Liquid cooling is usually a more superior option for AC systems. The liquid is able to keep its temperature, allowing for a gradual change in the car’s temperature. However, how well it performs will be governed by how robust the battery management system is.
  • Air cooling. Air cooling systems can be particularly beneficial to low-resistance battery cells. However, this can be costly due to it needing to be constantly on.

The Ramifications of “Fast” Or High Charging

High charging and discharge rates can be detrimental to the battery, especially in extreme ambient temperatures. Fast DC charging systems, where up to 80% of a battery is charged extremely quickly with the last 20% being charged via a trickle, can also do a number on the battery’s system.

A Word on AC Charging

Some hybrids use an AC system that uses an electric motor rather a drive belt. The innards of the electric motor are usually immersed in lubricating oil, which is usually nonconductive. Contamination of this oil can easily throw the electric system off by effecting its dielectric properties.

For the battery’s health, as well as the AC system, it is essential that you service your hybrid vehicle’s AC system on a regular basis. Hybrid cars are still a novelty, but owners should maintain their battery to ensure that there aren’t underlying issues.