Could heating the batteries in winter extend range ?

I am realizing the extend of the range gain as temperatures are rising.

I am planning to install a diesel heater for next winter.

Once an efficient source of heat is available, could one imagine to also warm up the batteries in order to extend their range during winter ?

Doesn't the cold weather package do that?

Might be, but that would mean using electricity to warm up the batteries.

If they have really implemented such process, then it would be definitely worth using some of the heat from a webasto to warm up the batteries...

http://myimiev.com/forum/viewtopic.php?f=10&t=429

Yep, the stock battery warmer only comes on in serious subzero conditions. I'd love to reprogram it for pack optimization, say conservatively to 60 deg F. An alternative, and less efficient method would be a radiant heater on the floor under the car, or a fully heated garage. Sure, any method will cost a few more electrons or fuel, but winter's when we need more pack capacity, not less, and I'd accept higher consumption in return for lower depth of discharge and a healthier battery pack. I'd be skeptical that only cabin heating would help the pack temp very much, given that heat rises, unless the car were maintained at constant temperature at all times when plugged in, and not just for 30 minutes of preheat.

Then is the battery warmer a liquid based circuit or electric ?

If liquids, does it use the same heater as for the cabin?

If yes, we might be able to have a Webasto diesel heater keep the batteries at say 10c to avoid too much discharge...

There is so much to do to optimize EVs. We are just at the begging of the story.

Once solid state batteries are available then all of this will be moot.

I think that batteries *are* warmed by charging them. The main cause of reduced range in cold weather is the energy used for heating the cabin, the defroster, etc. These can use as much energy as moving the car. Use the heated seat(s) or use an electric heated vest (like motorcyclists use) to stay warm. The defroster is the one thing we cannot improve on our own - all EV's should use the type of defroster that Ford and others had way back in the 90's, that had a extremely thin coating of gold on the glass, and cleared the glass in about 3 seconds. They heat the glass directly, like the rear defroster - but without the lines.

The stock battery warmer only comes on in serious subzero conditions. I'd love to reprogram it for pack optimization, say conservatively to 60 deg F. An alternative, and less efficient method would be a radiant heater on the floor under the car, or a fully heated garage. Sure, any method will cost a few more electrons or fuel, but winter's when we need more pack capacity, not less, and I'd accept higher consumption in return for lower depth of discharge and a healthier battery pack. I'd be skeptical that only cabin heating would help the pack temp very much, given that heat rises, unless the car were maintained at constant temperature at all times when plugged in.

There are two grilles behind our back seats. Are they battery in and battery out for battery ventilation?



from "What is this"

http://myimiev.com/forum/viewtopic.php?f=9&t=1542

Putting a pc fan inside and connecting it to the diesel heaters power switch ...

On the other hand some of us (CHAdeMO socket) can hear and watch the battery fan working when connecting the J1772 charging cable during selftest.

I wonder if pushing ~ 20C air into the battery will really warm it up. The mass of heat contained is so little compared to the batteries.

We might need a dedicated heat exchanger (from diesel heater to battery area) for that function. But that is definitely much more complicated to implement.

Why not install an insulation around the battery box during winter time?

Llecentaur said:

Why not install an insulation around the battery box during winter time?

Click to expand...

It is not simply a battery box. It is half the belly of the car but isolating is a good idea.

Charging in the wild, at night and in the rain for some 4 hours at least is torture and our 5 kW heater will outperform the charger with its meager 3.3 kW if it is really cold. Ours does not even heat at all when plugged in. So Karin and me have begun looking for something arctic proof.

If it was not for the heat we still need it for defogging and for keeping the car dry.