EV batteries are impacted by extreme hot and cold temperatures, which can effect their performance and life.Where a warm/hot battery battery could hold a charge longer but could impact life.Whereas a cold battery would not hold a charge as long.
I understand, during charging there is heat gain. More with fast charging.
What is the ideal temperature for (Aperta’s) lithium-ion batteries 40-100 kWH packs ? 1) while in a garage/charging 2) operating temperature
Could routine normal charging vs rapid charging be optimal for battery life?
I imagine charging frequency and use power(%drain) might factor in too...
🤔I understand there was a 2015 “lizard” battery, which are more heat tolerant. Any experience on that technology? If any advantage...could certain lithium-ion batteries types be considered / offered for different climatic zones? Living in the SW... impact from heat would be my immediate question, but I also do cross country travel in the winter months. I don’t own an EV vehicle so I am not sure what manufacturers out there are recommending and what people are actually realizing.
My family has 3 EVs at the moment, and we had 2 others previously. My extended family has had a total of 12 EVs since 2012. We have had 4 Leafs, 2 i MiEVs, 2 e-Golfs, 2 Bolt EVs, 1 i3 REx, and 1 Smart EQ.
Most / all of them had heating in the pack - it is a must for cold winters - we live in New England. And a few have active cooling, and the Chevy Bolt EV has liquid cooling. Cars go through extensive testing, and that includes temperature extremes.
Wow! Lots of “electrified experience there”.
Given that line up of various commercialized EV cars.. we know who to query especially, with New England seasonal temperatures/conditions.
Even though my family member’s Volt and i3 REx experience is also from the east coast, for selfish reasons... I may ask questions meaningful to my present SW heat. Although our 4200’ mountain elevation location offers a nice micro-climate.... I have a need to explore the many environments throughout the US.
Hi Neil
I am not sure if any of your family of EV cars have similar electric motors to each wheel... like the new Aptera but, do you think the the new Aptera AWD will be quieter than the 2e which had a motor under the hood/FWD ?
@Len The most common source of noise in EVs is the reduction gears, so the new Aptera won't have that.
Thank you. Nice to hear
I I live in Chandler Arizona. The LEAF batteries are all still failing very fast. The new lizard are just as bad. They refuse to add Battery Thermal Protection with liquid cooling. The KIA SOUL Had air cooling and all 10 I tracked down had failed.
A lithium battery in a COLD or HOT area needs Batterty Thermal Control.
Aptera mentioned planned cooling but lots to be verified. As an EV owner in the hot SW.... what would you recommend “in general” to try to minimize owner battery concerns including extended warranty etc?
I am hoping these attributes will help a little:
-The unique resin filled composite body’s Insulation
-The full time venting to help bring the interior to ambient outside temperature, with the solar powered venting
-Chris’ business experiences with Flux/ lithium barriers
@Len Battery will be cooled with coolant lines in the bottom of the body of the Aptera, possibly direct and/or heat exchanger with air conditioning. Don't know if heating will be with a heatpump or resistive. There is a slight chance it won't have a battery heater but definitely has cooling. I'd have to look back at the WeFunder QA
I think thats my main criticism of our i3Rex - when it's cold and you need wipers and heat the range plummets from 110miles in summer to about 50 miles for most of November til March which is a bit dull when the commute it was bought for is a round trip of 220 miles...I think the hot / cold debate needs to consider the non continental climate. We're at latitude 59 north here in the UK but marine climate.
The lizard battery was still very poor in the HEAT. I know many people with them and they fail just as fast as the original battery pack. An electric vehicle needs liquid cooling. Tesla and Chevy do it best.
Yea my Chevy Volt is aggressive with cooling. Turns on the AC when the pack reaches 85°F until it cools to 78°F. 200K miles still has 85-92% of original KWh.
I work in Minneapolis and can choose which ramp to park in. One outside on the roof and another underground and heated.
At what point does leaving it in the sun and cold w/full solar worse than just leaving it in a heated garage?
Since the Aptera has been designed to handle arctic nights, sunny Minneapolis days won't hurt it at all and will partially recharge the batteries. Then again if you have enough charge, might as well keep it warm.
Another solution is heat pipes, which are passive and will work to heat or cool the batteries. Although, since the motors are liquid cooled, my guess is that the batteries will be too. If the heat is being dissipated on the bottom of the car, it will have to somehow conduct through the insulative shell without compromising the structural integrity. One solution would be a graphene-lined aluminum plate or oscillating heat pipe recessed into the composite shell to maintain aerodynamics, and heat pipes to bring the heat through the shell through several small homes in the composite shell. Heat pipes can be very inexpensive in quantity, with thermal conductivities >1000X that of copper.
aptera mentioned to look into integrating cooling into the skin of the car. Sounds very interesting but also complicated and expensive. Also the sun shines from the top and to the side warming / heating those parts.
The natural location for a cooling system is the underbelly of the car where the battery will be located anyway.
I would look into an exposed active heat sink in the underbelly of the car. Which could form part of the battery pack. This would give you an easy install and service of the battery pack including cooling.
They should use heatpumps to manage battery temperature and probably motor temperature and cabin temperature as well. For heating, they are about 3x as efficient as resistive and for cooling it’s the only efficient way to cool below ambient temperatures. The big deal is they don’t really care what the heat sink temperature is as long as it’s between around -10F and 120F. That’s why Tesla is moving to heat pumps in all of their vehicles. Move heat/cold from one place to another with high efficiency. In New England, Maine in my case, I assume I will be plugging in every night from about October until April, mostly to keep batteries at an optimal temperature. Also, a well insulated battery box will be helpful in both hot and cold climates.
LiFePO battery chemistry seems most promising so far from what I have seen. I have also seen batteries that have built in heaters to help keep them from getting too cold.