People in colder climates, or even just climates that have very cold winters, often ask me how the cold weather will affect their electric vehicles’ range and performance and what can be done about it. Inversely, I’ve also been asked by people in very hot climates how this heat will affect their vehicles.
While every car is different, it’s fair to say that batteries don’t like the cold – especially lead acid batteries. I once read that an extremely cold winter’s day can reduce your battery performance & range by around 30% with a lead acid battery pack. That means while you may have 40 miles of summer range, your car’s usefulness could be chopped down to 27 miles when it snows.
The solution to this problem is as simple as heating and/or insulating your batteries. Though admittedly there are still issues to work around. First of all, you need to find a way to insulate the batteries while still having an airflow to remove the hydrogen gas that forms when charging. Secondly, you need to ensure your batteries are still warm, even for an hour or three after charging has finished.
For cheap, lightweight insulation solution I suggest using foil-coated foam-rubber sheeting (around ¼ of an inch thick) applied to both the inside and outside of your battery boxes, creating a double-layer.
You may then want to look at either a heating mat from a waterbed, or making your own from under-floor heating element sheets. They’re paper-thin and available at many hardware/electrical shops.
To keep your batteries warm while maintaining an outside airflow I suggest reducing your airflow to be as gentle as possible, as not to chill your batteries.
In addition to that (if your car is parked outside in the snow) consider installing an insulated, plastic vent flap which closes 10 minutes after charging has finished (once all the hydrogen gas has been extracted) through a turbo-timer.
These external vent-flaps can be found on many home renovation shops in the extraction fan department, and turbo-timers from any auto parts store.
Timing your car to be freshly charged just before you leave will also ensure the batteries are warm and ready to go. This may eliminate the need for heating pads/elements under your batteries too, as batteries will often warm up during charging. The batteries will also stay warm when driving due to the loads placed on them.
As long as you’re not leaving your EV alone in the snow for more than a couple of hours without heat or use, your batteries should remain warm and useful when you’ve finished shopping etc.
As for hot climates, lead acid batteries love to be warm and aren’t bothered by summer heat. Controllers on the other hand don’t like to get too hot, and can overheat and fail in extreme temperatures. Even if your controller doesn’t appear to be suffering, I can promise you it’s screaming on the inside and it’s life is shortened with each hot mile you drive.
The solution to this is simple. Use a fan and heat-sinks to keep airflow going around your controller. You could make your own heat-sink out of aluminum, or many EV parts dealers sell ready-made heat-sink kits with fans built in. Some controllers even have an option for water cooling – ideal for climates where the temperatures regularly get over 100° F (38° C).
In short, whatever your climate, there are practical, simple solutions available. You might even think of a solution that hasn’t been done before. Whatever you do, don’t let the local temperature get in the way of breaking your oil addiction!
