MemberAugust 15, 2021 at 3:00 pm
I’m wondering if Aptera will be using any of the advanced insulation technologies for the batteries ?
Things like the Panasonic Vacuum insulated panels (R45 of thermal insulation from only 15mm thick) .. or other similar advanced options that insulate very well without consuming allot of space or weight.
Some other modern BEV can spend allot of power/energy on the battery counteracting the outside air temperatures .. like a house cooling it in the hot summer days , and heating it in the cold winter nights .. and like a house , passive measure like insulation make a very big difference in how much energy needs to be spent .. but many other BEVs seem to put nearly no heat insulation in at all .. and like a old drafty house they have to spend allot of power/energy to heat it or cool it .. I’ve read the Tesla3 for example has ~3kw of battery heating capacity .. and sure it isn’t always used on every winter night at full power , etc .. but .. like insulating your house .. closing windows when the heat is on in the winter .. putting on a coat when you go outside in the winter .. insulation just seems like a much more energy efficient way of approaching that.
With the Aptera’s lower operating consumption per hour or per mile (better aero , weight ,etc) , tat means less waste heat .. thus less available to ‘self heat’ the batteries with .. and smaller lighter batteries also mean less battery thermal mass , while parked (unplugged) over cold winter nights or 3 day weeks and such .. but to me .. modern insulation options seems like a perfect solution.
MemberAugust 20, 2021 at 11:38 am
According to Sarah’s update, batteries will be one of the engineering areas that will receive an in depth webinar later this month with an associated Q&A. We should know better then. I am sure the engineers have done good do-diligence on battery technology in the context of scheduled production.
MemberAugust 20, 2021 at 3:30 pm
John, can you tell me how to find Sarah’s update?
MemberAugust 20, 2021 at 4:44 pm
instead of only turning of heater and AC for battery, how about also having insulation that can be locked into place but also removed for more ventilation surface area when environment is too hot. such temperature changes wouldnt happen much often, so even a manual chain and strings and gear tooth locking chain from moving can allow user to cover and lock/open and lock the insulation in place when told to by the screen inside. sure this could be electronically automatic, but why add such inefficiency when such simple manual adjustment wont happen often anyway.
MemberAugust 21, 2021 at 2:51 am
They have already reported ‘active battery thermal management’ .. which means they already have a heat exchange medium (air or liquid) inside the battery compartment to add or remove heat to the battery as needed .. the only place the Aptera has to remove heat would be the aero skin exterior radiator .. one could have the layer of insulation in the composite sandwich between the battery case and that skin radiator .. like putting a hot oven (radiator) right next to and touching your colder fridge (air conditioned battery/cabin) .. We know those two are right next to each other on the bottom of the car .. To avoid a bunch of wasted energy by the two fighting each other .. It would be best if there was a highly thermal insulative layer between those two hot and colder items … For my 2 bits .. the best option to give the most insulation in the smallest space and lightest weight , to do that would be something like those super thermal insulative vacuum insulation panels Panasonic makes.
When sitting in the winter cold teens or single digits over night .. or over a holiday weekend .. without insulation .. or wasting allot of energy keeping it warm .. the battery will drop to those cold ambient temperatures .. ice cold batteries have poor performance. Which is why every BEV on the market has a winter time battery heating system .. but my 2 bits .. a well insulated battery will need far less of that energy to keep it warm in winter .. and insulation also vastly reduces the amount of energy needed to keep the battery cool when parked backing in the hot summer sun all day .. or keep the battery cool from the hot skin radiator right next to it when under heavy load / use during those hot summer days.
MemberAugust 24, 2021 at 7:55 am
Thanks Ian for the link to the Panasonic product. That’s an advance in insulation tech I hadn’t known about. I agree. Aptera ought to be taking advantage of this for both battery pack insulation and passenger cabin insulation. The Panasonic VIPs appear to be delicate though, and can’t be bent into sharp curves. If the vacuum is lost in the panel, say, though an accident, then the panel loses 90% of the insulation value. R60 drops to R5. But sandwiched between the water formed aluminum battery cases, or the cabin roof composites, these VIPs could be great.
MemberSeptember 19, 2021 at 4:21 pm
I’m curious about insulation on the belly side as well. I frequently drive across the Mojave, Sonoran, and Chihuahua deserts, where summer pavement temps can exceed 140F. I had to line the floor pan under the carpet of my old Mazda with dense thermal mat to keep it from baking me like a Thanksgiving turkey. I’m wondering how Aptera battery cooling will work, with the skin cooling surface on the belly and no fans or radiators, on summer desert highways—or, worse yet, in stalled traffic on Phoenix streets, with no airflow under the car.