Long Term Storage

[peter-jorgensen]

I’m 99.99986% sure there will be the ability to limit max charge levels… It’s commonplace and considered essential in modern EVs.

[ray-holan]

Good point, John. I know many mainstream EV manufacturers protect the longevity of the battery pack by limiting charging to something like 90% of maximum capacity and limit discharge to 10% of capacity. It’s my understanding that lithium batteries, like our old buddies the lead-acid batteries, do not last long (i.e. number of discharge cycles is reduced — I mean the number of times you can discharge and recharge the pack) if charged to max and discharged to zero.

[llewellyn-evans]

Storage mode. Do you mean like a master switch on the battery?

[john-bussjaeger]

Many months of sitting unplugged it should do whatever protects the battery; disable features and yes, even maybe turn off the battery. If plugged in or in the sun with solar then it should limit charging and probably still disable most features. This could be like a built-in preset which sets max charge, disables any power using extras; could minimize security settings too.

[trollfaced-hudagmail-com]

i guess this can be the same physical plug to disable electrics after a crash, for fire fighters

[david-macfadyen]

Regarding battery health , what is the recommended practice for the Aptera. If an EV is not driven for several months – the battery pack should be kept @ 60%. The Aptera will have continuous charging from the solar cells …. (?) Should the Aptera be covered or stored in a garage for long term storage ? TIA

[jeff-siddons]

I winter in FL and summer in Quebec. I asked a friend, who is an Electrical Engineer, if he thought I could leave an EV in an unheated garage over the winter in Quebec. I pull a trailer up to Canada and back down to Florida so the Aptera wouldn’t work for me. But it would be great in cottage location where fuel prices are relatively high.

His answer was no I shouldn’t do that.

The garage has access to electricity. I could leave the EV plugged in over the winter and/or heat the garage. But that seems wasteful.

I have a brother-in-law who goes up to his cottage (across the road from my cottage) in the winter and he could look after the EV and do some chores to help maintain it.

Any thoughts?

Thanks

Jeff

[ROMAD]

You could put one of these on the 12VDC battery

https://www.amazon.com/12-volt-battery-disconnect-switch/s?k=12+volt+battery+disconnect+switch

[Mike-Mars]

> “His answer was no I shouldn’t do that.”

Did he give any reasons? If he just gave a bald statement it isn’t very useful.

> “… he could look after the EV and do some chores to help maintain it.”

What chores did you have in mind? ICE vehicles need to be driven once in a while, but I don’t think that is the case for EVs.

[harry-parker]

I’ve seen this Q & A for other electric vehicles. This answer always is, that’s no problem if you keep it plugged in to trickle charge the batteries (the main one and the auxlillary one as well). I’d set the vehicle to keep the battery only about 50% charged for the longest life. I’ve also read you should also jack up a car so that the tires don’t develop flat spots.

Alternately, having a friend let the Aptera out to soak up the Sun and recharge once a month or so would also do the trick.

[wingsounds13]

Plugged in and set to 50% limit is good, and almost complete: EXCEPT… Will Aptera maintain the 12V battery while dormant, or does it have to be turned on in order to charge the 12V battery? I gather that some EVs will (or can be set to) maintain the 12V battery while “off” and most will not. No idea which ones do it right and which do not. I do get the issue is that to do this maintenance they would have to “turn on” occasionally to close the contactors to the HV battery.

[harry-parker]

Good question. Aptera will be unusual in that its 12 volt battery will also be a lghtweight Lithium one rather than the much more common Lead acid type. Do Lithium ones need trickle charging more or less often than Lead ones?

[wingsounds13]

While lithium batteries have very low self-discharge rates, that is not the issue. All modern vehicles have vampire loads and Aptera is sure to be no exception. The question becomes whether Aptera has an accessory battery maintenance cycle while the vehicle is dormant. Hopefully it does.

[david-marlow]

Long tearm storage is not good for any EV. Any batteries degrade mainly with time and higher tempetures, not miles. Lithium batteries do best if kept at about 1/2 charge. lead acid batteries should be kept about fully charged. So keeping it plugged in while being stored will help the lead acid battery but not the lithium battery.

[Mike-Mars]

> So keeping it plugged in while being stored will help the lead acid battery but not the lithium battery.

It is normally possible to control the charge. e.g., set it to 50% maximum SOC, and 1kw maximum charge rate. That should be completely safe. Giving it a source of power would also allow the vehicle to control it’s temperature if it gets too hot or cold, and allow the cameras & OTA-updates to operate without killing the battery.

[john-malcom]

David, Aptera does not have a lead acid battery. The 12V accessory battery is lithium ion to reduce weight.

[Greek]

The 12v Lithium battery hopefully will last the life of the car…not just weight savings.

[john-malcom]

Lifetime of lithium ion 12 volt batteries averages 2 to 3 years or 300 to 500 charging cycles. Max life about six years. Think about how long your lithium ion battery in your cell phone last holding a full charge.

[david-marlow]

Battery life times are greatly dependant on good battery managment, with no batttery managment what John says is true. But with good battery managment you should be able to get well over 1000 cycles and over 10 years.

[john-malcom]

David, the above is for the 12 V lithium accessory battery not the motive lithium batteries. There is no battery management that you can “Control” for the 12V accessory battery. It charges and discharges much like any accessory battery.

[Jeff]

It will get topped up continuously via DC-DC converter from the high voltage battery pack when the car is on. Depending on how much “vampire drain” there is when the car is sleeping, it should be possible to keep it in a narrow voltage range and minimize degradation associated with charge/discharge cycles.

[david-marlow]

I can’t understand why someone would want to use a lithium battery this way, when a the 12v AGM lead acid accessory battery in my Volt has lasted 12 years.

[ROMAD]

David, I tend to agree on that. I may just swap out the lithium for a good AGM battery and use a battery disconnect switch for any long non-use times such as vacations. That way there won’t be any dark current to discharge the battery (nor any chance of a lithium fire however slight).

[john-malcom]

It is the weight and size advantage of the lithium ion battery over any lead acid battery. I trust Aptera engineers to do the right analysis and make the best decision on how to provision the Aptera. Of course you are free to equip the Aptera with any battery that fits the form factor of where the battery resides in the vehicle and meets the power specifications once you own the vehicle if you think you have a better technical solution. There may be a possibility that a more expensive lithium batter may go away in favor of a less costly alternative.

• This reply was modified 1 month, 3 weeks ago by  John Malcom. Reason: Correct spelling

[jeff-siddons]

So from what I’ve read so far, on this discussion thread, I may not need to heat the garage during the winter season as the Aptera will be able to heat itself when it requires heat?

[Jeff]

Yes. Please don’t heat an entire garage just to keep any EV warm.