Charging for winter storm/power outage

[The Weatherman]

6.5 KWH based on 131 useable.

Not sure how much we will pull during any ‘short’ term outage (1-2 days) but it’s really up to the individual to do what works for them.

If you consider the KIA Ev recommendations they suggest changing to 100% every month or so. It is used by the BMS to mange the battery charging logic. (I haven’t met that standard but have charged up there every couple months.

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[MotoGary]

If I believe everything I've read online, I've most likely already ruined my battery! So if a big storm or other emergency is coming that may result in a power outage...I'm filling my ICE vehicles to the top, and charging my EVs, eBikes, Dewalts, and nose hair trimmer to 100%. I also wouldn't hesitate to keep my Lightning at 100% every day until things normalized. Ok, maybe I'll go 99% on the Lightning and sacrifice 1% as a small offering to Zeus.

 

[Kit2874]

Hey everybody,

I wanted to get some advice from other battery nerds.

We are anticipating an ice storm and looking at the potential of losing power. I have my house set up to run off of my trucks generator.

I would like to charge to a higher percentage, but there’s also the possibility we don’t lose power and I don’t go anywhere so the truck is sitting in the garage for a few days.

What do?

I was thinking 90%? Maybe 95? My daily routine is usually 80%.

Your truck won't explode if it's charged to 100% and sits there for a couple of days.....

I guess I am the only idiot that charges it to 100% all of the time on this forum.....

 

[duncanmaio]

Your truck won't explode if it's charged to 100% and sits there for a couple of days.....

I guess I am the only idiot that charges it to 100% all of the time on this forum.....

I have about 78K miles of daily charging to 100%. Most days I also drive almost 100 miles, but I often charge up on Friday night and don’t go anywhere until Monday. It’s fine.

 

[Firn]

Fwiw, degredation doesn't just, "happen", it is ALWAYS happening.

It's happening at 80% the same as at 100%, its just a little faster at 100%.

Remember heat is a big factor too. And with the cold temps that degredation is going to slow.

100% isn't really much difference in energy than 95%, but it also isn't really any different in degredation. I would charge to 100% and not think a second thought about it.

 

[Henry Ford]

Risk/reward. If you charge your battery to 100% it will statistically die 8.3 miles sooner than if you charge to 80%. This is a scientific fact*. If you are the only house on your block with power during the storm of the century you will be a hero to your family and be praised by your efforts for the rest of your life. It will be a leading fact in your obituary#.

This is the same reason I hit driver into the short par four surrounded by sand. If I shoot a 112 instead of a 110 nobody will care but if I hole out a par four people will celebrate my glory for decades^.



* this is not a scientific fact.
# it will not be a leading fact in your obituary.
^ I will celebrate my glory for decades.

 

[Calvin H-C]

I have a seven year old Focus Electric approaching 100,000 miles, which translates to at least 2000 charging cycles. The battery is still going strong. It can ONLY charge to 100% unless I stop it manually. I don't charge it when I know I won't be using it the next day or an extended time if I'll be away just so it won't sit at 100% for long.

That said, the effect on the overall life of a battery by charging to 100% and leaving it for an extended period for a single occurrence (or even a few of them over its lifetime) will be insignificant.

Better to have the full charge in case it is needed than to not have it. Besides, it has been mentioned on other threads that the battery's management system balances the cells when it is charged to 100%, and it's likely a good thing to do this at least once every month or two. Dare I say that never charging to 100% may be as bad for the battery's life as always charging to 100% is.

Things like ratings are not absolute. They work on a sliding scale. When was the last time you heard of an elevator cable breaking because it's 2000 lb limit was exceeded by a few ounces?

 

[Adventureboy]

I would charge to 90%. If you lose power, you will get several days and up to a week out of the truck without problems provided your heating isn't electric and you are careful.

Having used it to run my house during an outage, I'd easily get a week if needed running the refrigerators, freezers, furnace, internet, TV and basic lighting and cooking.

 

[SpaceEVDriver]

I charge to 100% all the time and still have perfectly fine State of Health on both the '22 Mustand and the '23 Lightning.

I don't know what brand-T does with their battery, but the actual charge on the Lightning battery when the display says 100% is closer to about 92%. In other words, the Lightning battery is never charged to 100%, even when it displays 100%. The ER battery has a rating of 143 kWh with 131 kWh usable (91.9%).

 

[ScubaSteve_TheReal]

Why wouldn't you charge to 100%?

I would not worry about charging to 100% at all. Zero, nada, no worries if it is me.
1, this is actually not a bad thing periodically to do for cell balancing.
2, it’s an exception charge just like going on a road trip when you charge to 100% from home.
3, it’s better to have it and not need it vs need it and not have it.
4, doing so is one reason I can sleep better at night and also knowing we have a really good battery warranty.
5, see 1-4 … JMHO

 

[Grumpy2]

I wanted to get some advice from other battery nerds.

Ha! Have you got an answer? I just hope your power doesn't go out.

 

[chl]

There are all kinds of technical reasons why charging Li batteries to 100% speeds up deterioration or even causes short circuits in a worst case scenario.

You can search and read all about it, things like Li ions tendrils/dendrites and plating on the electrodes, the effects of heat stress getting to 100%, the high voltage level inside the cells when at 100%, etc.

But, like others pointed out, there is a buffer to minimize the degradation, when the dash says 100% it really isn't. But even going to 90%, if that is what '100% really means, can shorten the lifespan of the battery. How much who knows?

Tesla CEO EM has said as long as the vehicle is not kept there for 'any length of time,' 95% is fine - but how long is any length of time? Again, who knows?

However, it seems that discharging the battery by more than 50% SOC is worse according to some studies, e.g., from 80% to below 30%. Limiting the depth of discharge to no more than 50% compared to a deeper discharge will have a significant impact on longevity.

Then there are the warranty and owners manual cautions about the battery.
Not following them will mean any damage that occurs as a result will not be covered by the warranty. How do they prove that? I guess they keep records of our charging history for example.

By the way one of the things they say is...

WHAT IS NOT COVERED?
Damage Caused By:
...
• abuse and/or misuse of the vehicle and/or high voltage battery
pack, such as driving over curbs, overloading, racing or using
the vehicle as a permanent stationary power source

Hopefully, we can safely assume that what they mean by "permanent stationary power source" would not include using the Pro Power outlet as a temporary emergency backup power source for your home in a power outage?

Who knows.

 

[Dinozero]

There are all kinds of technical reasons why charging Li batteries to 100% speeds up deterioration or even causes short circuits in a worst case scenario.

You can search and read all about it, things like Li ions tendrils/dendrites and plating on the electrodes, the effects of heat stress getting to 100%, the high voltage level inside the cells when at 100%, etc.

But, like others pointed out, there is a buffer to minimize the degradation, when the dash says 100% it really isn't. But even going to 90%, if that is what '100% really means, can shorten the lifespan of the battery. How much who knows?

Tesla CEO EM has said as long as the vehicle is not kept there for 'any length of time,' 95% is fine - but how long is any length of time? Again, who knows?

However, it seems that discharging the battery by more than 50% SOC is worse according to some studies, e.g., from 80% to below 30%. Limiting the depth of discharge to no more than 50% compared to a deeper discharge will have a significant impact on longevity.

Then there are the warranty and owners manual cautions about the battery.
Not following them will mean any damage that occurs as a result will not be covered by the warranty. How do they prove that? I guess they keep records of our charging history for example.

By the way one of the things they say is...

WHAT IS NOT COVERED?
Damage Caused By:
...
• abuse and/or misuse of the vehicle and/or high voltage battery
pack, such as driving over curbs, overloading, racing or using
the vehicle as a permanent stationary power source

Hopefully, we can safely assume that what they mean by "permanent stationary power source" would not include using the Pro Power outlet as a temporary emergency backup power source for your home in a power outage?

Who knows.

Lots of good points, but the one I do want reply to specifically, considering the F150 was advertised in many commercials as being a backup power source. I don’t think that’s what they mean when they say permanent power supply.

They even sell the whole emergency back up thing. That system puts even more on the battery than running pro power would.

 

[chl]

Lots of good points, but the one I do want reply to specifically, considering the F150 was advertised in many commercials as being a backup power source. I don’t think that’s what they mean when they say permanent power supply.

They even sell the whole emergency back up thing. That system puts even more on the battery than running pro power would.

Yes when I read that I wondered what they meant since they have that SUNRUN Home Integration System thing...maybe they mean if you use the battery like a power wall somehow taken out of the truck? Who knows.

The HIS seems to get 240V 40A through it's DELTA inverter, whereas the Pro Power is limited to 30A. Hardly worth the big bucks involved with the HIS for 2400 more watts. I have a FCSP and thought about the HIS, but then I read so many horror stories about it and checked the price tag and thought, nope.

I'm sure if you used the HIS frequently it'd take some lifespan off the battery, especially if you exceed the recommended 50% depth of discharge limit often.

We are supposed to get a heavy snow, maybe ice storm as well, starting Sunday here in the Va-DC-Md area. I have a gasoline un-bonded generator and transfer switch set up already to run emergency circuits - going to test run it tomorrow just in case.

My transfer switch doesn't switch the neutrals so I can't use the Lightning ProPower.
I have a Generac neutral switching one as well, just haven't gotten around to wiring it to the house yet.

I have been thinking about how to 1) minimize the wiring changes when adding the Generac switch, 2) be able to use to the gas generator through the old switch sometimes when I don't want to use the Lightning for backup power so having two switches, and 3) be code compliant and safe doing so (and pass inspection).

I could wire the switches in series, Generac out to old switch in, but the old switch would have to be in Line mode when being powered by either the actual service Line (Generac in Line mode) or the Lightning (Generac in Gen mode) through the Generac, since the old switch is the "Load" on the Generac output.

Also, all the emergency circuit neutrals are moved to the Generac, and only bonded to the service panel when the Generac is in Line mode. So when using the unbonded gas generator through the old switch with the old switch in Gen mode, the circuit neutrals and the gas generator neutral have to be bonded through the Generac which has to be in Line mode to do so.

While there would not be any risk of back-feeding the service in either case, it could be confusing having one switch in "Line" mode when using the gas generator or the Lightning as the power source, and I can see an inspector having issues with that.

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