Hybrid Version - Battery Operating Temps

[Thirdeye]

While viewing the Popular Mechanics video it appears that the ICE and the batteries in the hybrid will be located in the same general location. From what I have read, the vast majority of battery types do not function well in extreme temperatures. It will be interesting to see how the Aptera folks engineer a solution to the heat produced from the small ICE in relatively close proximity to the batteries, especially in hot southern California locations. Conversely, I'd imagine that in very cold locations the ICE's heat (when operating) could be used to help keep the batteries warm.

Thoughts?

[LQUAN]

Not to worry much about heat problem. The gas engine is a water cooled single cylinder. By law, all petrol engine housing must have a firewall between the operator and the engine. The battery pack woul likely locate behind the firewall. When in motion, heat will get sucked out from under the rear wheel. When not in motion, the gas engine shut off. Therefore, you can be stuck in traffic and no heat will generate from either the motor or the battery. Don't forget battery gets hot too when outputing high current.

[cogito]

Depending on which batteries Aptera ends up using, I might want them on the other side of the firewall from me.

[KarenRei]

They're going with lithium iron phosphate, not lithium cobalt oxide, which is the type that likes to burst into flames.

Hmm... I'm searching, but can't seem to find any info... anyone know A123's nanophosphate price per watt? I'm imaging that Aptera is going for a battery that's about $1/Wh, since 10kWh would mean $10k, which would leave $17k for the rest of the car, which -- given the small size and simple drivetrain, but also the use of carbon fiber and limited mass production -- seems about right. I'm hoping for a fast charge battery system because I want my Aptera, when I can get ahold of one, to last me for at least a decade, and I expect to see charging stations popping up a few years from now. Given how fast E85 has spread, and how much less infrastructure is needed for a charging station...

[Thirdeye]

When not in motion, the gas engine shut off. Therefore, you can be stuck in traffic and no heat will generate from either the motor or the battery. Don't forget battery gets hot too when outputing high current.

In most cases I would agree. However, from what I have read most battery types should to be recharged if their stored energy falls below a certain percentage to maintain longevity and optimal efficiency. So if a battery is at the lowest allowable percentage level the controller should signal the ICE to start up to begin recharging, even if the car is stationary.

As you indicated the heat/cold quesion might not be an issue...in a mild climate. For the adventurous, Death Valley in summer or Truckee in winter might present a unique set of challenges!

[cogito]

They're going with lithium iron phosphate, not lithium cobalt oxide, which is the type that likes to burst into flames.

Hmm... I'm searching, but can't seem to find any info... anyone know A123's nanophosphate price per watt? I'm imaging that Aptera is going for a battery that's about $1/Wh, since 10kWh would mean $10k, which would leave $17k for the rest of the car, which -- given the small size and simple drivetrain, but also the use of carbon fiber and limited mass production -- seems about right. I'm hoping for a fast charge battery system because I want my Aptera, when I can get ahold of one, to last me for at least a decade, and I expect to see charging stations popping up a few years from now. Given how fast E85 has spread, and how much less infrastructure is needed for a charging station...

Retail price for a single 2.3Ah 3.3 V A123 cell is about $20 (7.59Wh or $2.65/Wh.) Most of us cut that price in half by buying DeWalt cordless tool battery packs off ebay and taking them apart. I’m sure in the quantities Aptera would be buying cells the price would hit your $1/Wh target. Auto batteries were their plan all along, power tool batteries were to prove they could deliver product.

[KarenRei]

Yep, sounds like those numbers are definitely in the ballpark. That certainly is encouraging for those of us who want a fast charge option :)

(Obviously not fast charge straight from your home's wiring, of course, but fast from an appropriately equipped service station or charging device)