Switch to a 48 Volt System

[ROMAD]

The 12vdc battery in the Aptera is just to provide power to the electronics when the vehicle is shutdown along with the auxiliary power outlet (a.k.a “cigarette lighter” port). Thus there isn’t the heavy demand that a large vehicle like the CyberTruck requires.

[curtis-cibinel]

48v is the future of vehicle electronics but Aptera does not have the funding to make parts themselves and sourcing them isn’t trivial. Maybe in 5 years for a refresh ss parts get available.

[ROMAD]

True, but I figured that was already in their long range plans but isn’t ESSENTIAL to the Aptera.

As an aside, the comm pallet I used in the USAF required the jeep to have a second 12vdc battery and a 100amp generator. With that generator, we could (and did) slave off APCs and tanks if they had dead batteries. Of course the two batteries were in parallel as it was current, not 24vdc voltage, that was required.

[craig-merrow]

I remember years back there was some work going on with solenoid operated valvetrains in ICE that required a 48 volt system. It was an interesting idea, but as far as I know it never got beyond the experimental stage.

• This reply was modified 2 months, 3 weeks ago by  Craig Merrow.

[Biker]

“I do understand the lower weight/cost, but is there a reason for Aptera to not do the same?”

The automotive supply chain relies on and mostly provides 12 VDC based electronics. Aptera relies on suppliers, it doesn’t make anything itself. Tesla will help/push the suppliers to make the switch, but that will take years.

[john-malcom]

I believe there is.

The reason is that the design, engineering, and sourcing of components is complete. Making a change would cost more in time and resources than any benefit that could be achieved from making a change at this point. The engineering group, in conjunction with manufacturing and finance have determined that the 12v system is the best near-term solution at this point considering all factors. Let’s trust Aptera to implement the best solution, and plan for a change if the benefit is there for a future iteration of the Aptera.

Let’s all support getting it in the hands of customers and on the road soonest! If successful, plenty of future time for different batteries, electrical system, other would like to haves.

[craig-merrow]

👍

[joshua-rosen]

Just to elaborate on what John said. In order to go to 48V you have to be able to get 48V components for all of the fiddly bits in the car. Tesla was able to go first because they build everything in their cars so they were able to design every system to be 48V. For everybody else you have to wait for the component suppliers to provide 48V versions of everything. They are all moving that way so you’ll see 48V become the new standard in the next few years but if you are designing a new car today it’s easier to just stick with 12V and worry about 48V later.

[ROMAD]

Yes, it took decades to switch from 6 vdc to 12 vdc, and also standardize on negative grounding. It’ll probably be the same for 48vdc (or higher) to replace 12vdc.

[john-trotter]

I certainly agree with all the “not now” sentiment, but there is also the point that, so far, the Aptera has a relatively simple control system and associated wire harness, so the benefit from going to 48-volts would be less than for the all-bells-and-whistles Cybertruck or other monster machines. Fewer wires first priority, smaller second.

[Kamakiri]

Considering the current PV setup with ~30 cell/~15V strings, it seems to be really impractical to switch to a 48V system for this 3-wheel vehicle. Perhaps for some future/larger/4-wheel/next sEV of theirs it would be considered.

[wingsounds13]

The solar cell configuration has nothing to do with the accessory system voltage. The solar cells feed into charge controllers that convert their output to main battery pack voltage (~400V if I remember correctly). Power from the main pack is then converted to accessory power level (12V) to charge that battery and maintain that system.

[Kamakiri]

I certainly hope that’s not correct, but I can’t say I know what they’ve done. My understanding is that through any typical EV setup is that the battery pack isn’t charged *through* the HV BUS. so I don’t see putting the PV out and bumping it to HV BUS voltage to then charge the pack. And while I know most other EVs *do* charge the accessory battery from the HV BUS, it makes sense as the sole source of energy to do so.

It’s my hope and expectation somewhat that Aptera handles the accessory system charging more efficiently.

[Mike-Mars]

For them to be able to do that, I think they’d need a second charge controller, and some way to divert current in both directions so that both charge controllers are running simultaneously & in parallel (which they are not designed to do). WingSound is describing the most realistic & practical setup. Also keep in mind that the solar cell output voltage is not fixed at 15v, it will change rapidly with lighting conditions. You can’t simply feed it directly into a 12v circuit.

• This reply was modified 2 months, 3 weeks ago by  Michael Marsden.

[Kamakiri]

For them to be able to do that, I think they’d need a second charge controller,

No or not necessarily, depending how the design arrived where it is

and some way to divert current in both directions so that both charge controllers are running simultaneously & in parallel (which they are not designed to do).

Not exactly sure what you’re saying here, but also ‘no’

One source like the PV array could easily be used to charge or power multiple voltages/types of output with one ‘charge controller’. Very simple commercially available devices do exactly that. See any Inverter or ‘solar generator’ type device.

WingSound is describing the most realistic & practical setup.

Disagree

Also keep in mind that the solar cell output voltage is not fixed at 15v, it will change rapidly with lighting conditions.

*avoids sarcastic response*

You can’t simply feed it directly into a 12v circuit.

more of a you don’t want to than can’t…because you actually *can*. Especially considering many different 12V battery chemistries possible. But that’s not at all what I’m suggesting.

[wingsounds13]

The primary purpose of the solar array is to charge the High Voltage pack, so its output _must_ go there. The 12V system is charged from the High Voltage pack, same as any other Electric Vehicle.

[Kamakiri]

The primary purpose of the solar array is to charge the High Voltage pack,

Yes

so its output _must_ go there.

No

The 12V system is charged from the High Voltage pack, same as any other Electric Vehicle.

I don’t know that, because it doesn’t have to. So unless you happen to actually know that, it may not be true. As I said, it’s not what I’d do. And I have a fair amount of knowledge and experience charging and maintaining various 12V systems with similar low voltage solar panels.

There are certainly reasons for Aptera to do what is and has been typically done with other EVs, but they also certainly do not need to when considering their ethos and design principles.

[john-malcom]

You are correct on all points based on Aptera information released to this point as well as good and efficient engineering practices. Perhaps some tweaks before actual production, but I would bet against it. I would disregard questionable statements to the contrary without any reliable substantiation.

[david-marlow]

So you want to set Aptera back another year?

[ROMAD]

Chill, David. 🙂

He was just offering it as a point for discussion and even said it was too late to do it now.

[daniel-crotty]

Thank you Romad. I was biting my tongue to not reply!

[ROMAD]

I believe a lot of these type “requests” come from those new to Aptera and the forum so they aren’t aware of everything discussed here in the last several years (or year regarding the LE). Thus we need to be patient an maybe just give them the link to where the pertinent announcement was made (if even WE can find it).