What SOC to keep tri-motor CT at?

[fritter63]

OK, so for just around town and Home Depot trips, I certainly don't need the full "500" miles of range (no, don't start with me on choice of CT motors).

I'm perfectly good with the SR+ charging to 80% twice a week most of the time.

So for the CT, Should I just let it run between 20 and 80% (that would be an overnight charge once a week if that?). Or keep it topped at 80% (I'm going to install a second charger for it). Or just run it between 20 and 50%?

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[FutureBoy]

I’m curious about this too. With ICE the general advice was to keep the tank topped up especially if not driving very much. I tend to drive enough though that I just fill up when I get below 1/4 tank and happen to be conveniently near my favorite gas station. Right now though that station is getting upgraded so it is closed. Luckily I’m not driving much because of the pandemic.

Anyway, I’m going to have to learn new patterns with my CT. If we truly get the new batteries discussed at battery day, I’m not too worried about wearing out my battery. But it would be good to at least know what the ideal charging pattern should be.

 

[Newton]

keep it at 100! which is probably more like 95.

but with these news chemistries we don't really know. that 80-20 thing is for lithium-ion thats been used in everything for years. personally i would prefer the iron based because they have bonkers cycle life and are fine up to 95%. but always a downside, they are heavier.

it seems we will be getting the high nickel batteries which i think are pretty new tech

 

[FullyGrounded]

Mine will be plugged into the charger that is fed by the battery bank, supplied by the solar panels. They are fitted with an auto-stop charge, so it will be plugged in when I get home, and unplugged when I head out. Simple. Most times, I will leave with 100%, but I won't worry about that other than to see that the charger is working properly.

It would be so cool if people with solar powered chargers; could be part of a network to allow a free charge to 1 vehicle per day.... so people could connect the dots and get free power all the way across the US and beyond. Thoughts...

 

[BillyGee]

Depends how far I'm driving and what the recommended use for the chemistry is. Standard practice at the moment is between 20 and 80, but permits overcharging for a longer trip.

I do 130 average miles every day, so we'll see what the on board calculator says.

 

[Crissa]

These will be lithium-ion. The closer to 50% you can keep it, the further from 0% and 100%, the better.

Shallow charging and away from uneven heating is best for cycle life.

-Crissa

 

[Jhodgesatmb]

keep it at 100! which is probably more like 95.

but with these news chemistries we don't really know. that 80-20 thing is for lithium-ion thats been used in everything for years. personally i would prefer the iron based because they have bonkers cycle life and are fine up to 95%. but always a downside, they are heavier.

it seems we will be getting the high nickel batteries which i think are pretty new tech

It’s right - that we don’t know. It’s about the battery chemistry, battery longevity, and battery usage (and probably other variables). Right now, with either the 1850s or 2170s, Tesla recommends leaving the car on the charger and running 20-80 except during trips. The lead-based batteries can apparently be charged all the way up, but ‘we’ don’t know about the new cell chemistries, the new cell technologies, or the new pack construction. Someone does.

 

[DarinCT]

I specifically chose the tri-motor for the range and hadn't even considered SOC around town. My most likely unscheduled round trip is 200 miles and along a major highway with chargers so it's not like I need a lot to be ready to go. Still, I imagine having a big mileage ready number of 440 miles will be fun to see.

 

[Idaho_7]

These will be lithium-ion. The closer to 50% you can keep it, the further from 0% and 100%, the better.

Shallow charging and away from uneven heating is best for cycle life.

-Crissa

Crissa, a related question: Say a battery (Not necessarily CT's, yet a Lithium-ion non the less) took 4 hours to charge 2-Hours from zero to 80% and another 2-Hours form 80%-100%. Given that assumption is it also cheaper to charge to only 80% compared to the charging costs for the last 20% (Unless full usage is required for that day)?
It seems that both Long Term Charging Costs and Battery Life would be maximized by charging to 80%.

 

[fritter63]

Crissa, a related question: Say a battery (Not necessarily CT's, yet a Lithium-ion non the less) took 4 hours to charge 2-Hours from zero to 80% and another 2-Hours form 80%-100%. Given that assumption is it also cheaper to charge to only 80% compared to the charging costs for the last 20% (Unless full usage is required for that day)?
It seems that both Long Term Charging Costs and Battery Life would be maximized by charging to 80%.

Yes, this what we typically do.

 

[BillyGee]

Yes, this what we typically do.

Correct me if I'm wrong, but I got the impression from a battery management video that Tesla cars have a built in management system based on your average daily miles. Is that true?

Also, does it actually add that much to let it boost up that last 20% before a road trip?

 

[fritter63]

Correct me if I'm wrong, but I got the impression from a battery management video that Tesla cars have a built in management system based on your average daily miles. Is that true?

First I've heard of that. Where is the video?

Also, does it actually add that much to let it boost up that last 20% before a road trip?

It's not a matter of cost, it's a matter of time (that last 20% ... or 10% really) takes a LOT longer. No big deal if you're charging overnight at home. On the supercharger it really adds a lot of time to it (see story below).

The issue however is that it heats up the battery more and that increases the build up of the chemical structures that eventually degrade the battery capacity. Think of it like stuffing your sleeping bag into it's sack on a backpacking trip.. At first it's easy, near the end it is difficult.

Supercharger story: Last year I went down to the SC in town to supercharge one our 3's just to do the "rebalancing" thing (since we rarely supercharge. There was a lady there with new Model Y. She was already charging. She was asking me about charging to 100%, and I explained to her why she shouldn't be doing that. But apparently she didn't listen, as she was STILL THERE on the charger by the time I'd gotten to 80% and left. I'm sure somewhere on the net (or on youtube) you can find a graph showing the supercharge times to different levels.

 

[TheLastStarfighter]

My plan is to get a CT3, and probably have it between 60-80% most of the time. I will rarely if ever charge to 100% to avoid degradation. But I also wouldn't let it run low, because you never know when there is an emergency and you need a full charge. Power outage, major storm, civil unrest, who knows. But there's no point in having an apocalypse machine with a dead battery when you need it.

 

[VolklKatana]

Correct me if I'm wrong, but I got the impression from a battery management video that Tesla cars have a built in management system based on your average daily miles. Is that true?

Also, does it actually add that much to let it boost up that last 20% before a road trip?

Yes, in some cases it does. In my 2013 Model S, charging the vehicle up to about 95% is the only way I can make it to my parents house and back. its an extra 30 miles of range on the screen, probably about 15 miles of usable range in all actuality. and there are no superchargers along the way, so increasing this percentage really does make a difference for these trips. my charge time for daily usage is usually less than an hour, but the remaining 20% can take hours to charge the rest of the way as the charge rate drops way down. To address this, i always try to up that percentage the night before to ensure I am at the desired percentage when its time to go.

 

[Newton]

i would love to have something greater than the CT1 because it gives more room in that happy zone.
for my thought process... ct3 500 miles range. so 400 is 80% , 100 is 20% which leaves 300 miles range
while ct1 300 range 80% is 240 20% is 60. so 180 range
for longer battery life

but for me that would be perfectly adequate

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