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Apologies in advance for what might be a newbie question

I understand that charging batteries to 100% routinely is not good for them long term.

I also understand that 100% on our cars is actually only 75 rather than 78 kWh ie not really 100%.

Does this mean that it is OK to charge to 100% every night or whenever free electricity is available?
 

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Apologies in advance for what might be a newbie question

I understand that charging batteries to 100% routinely is not good for them long term.

I also understand that 100% on our cars is actually only 75 rather than 78 kWh ie not really 100%.

Does this mean that it is OK to charge to 100% every night or whenever free electricity is available?
80% for routine charging is generally accepted as a sensible figure for any EV. As the available on the Polestar 2 is about 96% of actual then it’s still best to only charge to 100% if you need the extra range that day. Charging to 100% occasionally might actually be beneficial in balancing cells.
 

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The battery is 78kW. 73kW is for the Car and 5kW for reserve / system - that's about 7%.

If you really need that extra few miles daily … then yeah you could charge to 87-88% as that would still be 80% overall (roughly).

The question really is why do you want 100% all the time? or more than 80%? At 80% you get a range of 220miles. If you are doing that daily then you'll need 10hours per night charging.

Stick to 80%. Then go to 100% if you know you are going on a long road the next day - Also as @hedwri mentions ... once in a while maybe ... I don't know the data on that.

Also try not to go lower than 20% often unless you obviously need too.
 

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All depends if its owned or leased.

If leased then charge it 100% every night if you want, as degradation won't affect you.

If bought charging to 80% is commonly accepted as good practice. Though it is recommended to charge to 100% once a month. Too much fast CCS charging and very hot weather will also impact battery degredation. Unless you need the range for daily driving, I would wait till charge to falls to around 25% to 30% to recharge. Daily charging is not meant to be good for the EV batteries
 

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I would wait till charge to falls to around 25% to 30% to recharge. Daily charging is not meant to be good for the EV batteries
I've not heard this one before. My understanding is that most EVs like to be left plugged in each night, and the benefit is you have full range (80%) available each day and you can pre-heat/cool your car with wall power instead of battery power.
 

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A Lithium-ion (Li-ion) battery does not like being at full charge. In addition it doesn't like maintain a full charge for long.
The same applies to the opposite end of the spectrum at 0%.

They also don't like too much heat or be too cold (but heat worse that cold)

What they don't mind is a mild fast (I used the Term fast for 7kw) charge daily if they are used daily.

If you are planning on leaving your car parked for a long time, like 2-4 weeks drop the charge to 50% and leave them plugged in ... they batteries prefer this too as it's less stress on them.

This video is very decent.

 

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If you are planning on leaving your car parked for a long time, like 2-4 weeks drop the charge to 50% and leave them plugged in ... they batteries prefer this too as it's less stress on them.
This is different. Agreed that the car should not sit for an extended period plugged in and fully charged. But each night it is preferable. Not certain about the P2, but when you plug in, the cooling/heating will take place to stabilize the battery, and on very hot/cold days the same will happen if the car is plugged in.
 

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This is different. Agreed that the car should not sit for an extended period plugged in and fully charged. But each night it is preferable. Not certain about the P2, but when you plug in, the cooling/heating will take place to stabilize the battery, and on very hot/cold days the same will happen if the car is plugged in.
What's the magnitude of these effects?

Think we need to operate under the assumption that many if not most EV owners are not as sophisticated as y'all and have been charging their batteries based on what's most convenient rather than what's technically optimal for maintaining battery life. And even with that, as long as there's active thermal management (unlike the Leaf) battery life seems to be overall fine across different OEMs and cell manufacturers.

and as someone else indicated, if you're leasing the P*2 seems like the heaviness of your right foot is going to be more the major determinant of range, etc. And even if you are buying it and following some simple general guidelines (generally charge ~20->80%, save 90-100% charging for stars of road trips), then seems should be fine for the time period of the battery's warranty?
 

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What's the magnitude of these effects?

Think we need to operate under the assumption that many if not most EV owners are not as sophisticated as y'all and have been charging their batteries based on what's most convenient rather than what's technically optimal for maintaining battery life. And even with that, as long as there's active thermal management (unlike the Leaf) battery life seems to be overall fine across different OEMs and cell manufacturers.
That's why you are here :)

The manual probably also has good information on this.
 

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Watch the video .. the TLDR is that batteries with thermal management should be fine as long as you stay within the 80-20% as much as you can.

If you can't ... don't wait 8 years to sell it 😉
 

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Watch the video .. the TLDR is that batteries with thermal management should be fine as long as you stay within the 80-20% as much as you can.

If you can't ... don't wait 8 years to sell it 😉
I want to watch the video again carefully, but what I'm getting out of it for now is that instead of waiting until I'm down to 20% (a few commutes), I'm better off charging every night after the commute up to 80%. More charge cycles, yes, but much less depth-of-discharge.

But, yeah, I have to study those curves a bit more.

Great video, Dank. Thanks.
 

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I want to watch the video again carefully, but what I'm getting out of it for now is that instead of waiting until I'm down to 20% (a few commutes), I'm better off charging every night after the commute up to 80%. More charge cycles, yes, but much less depth-of-discharge.

But, yeah, I have to study those curves a bit more.

Great video, Dank. Thanks.
Yes DOD seems more important than anything else. However that's hard to explain to the general public.

But for us ... doing 75-65% daily was better for the battery than doing 80-20% weekly.
 

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Source for this?
You are right that the statement "Daily charging is not meant to be good for the EV batteries" is my opinion, that less you can charge Lithium batteries the better (w/o letting battery go below 20%) .

My charging routine is based various studies I have seen. So what I am saying has been tested in studies, whereas the assumtion that nightly topup (random %SOC to 80%) is good, I can't find any studies that show that.

For example this study, see figure 8.

It shows lower degredation at the same number of charge/discharge cycles, so 75% - 25% is better than 85% - 25%, which in turn is better than 100% - 25%.

I use the car daily and use approx 12% charge per day in my commute, so I charge every 4 days. Till I see a study that shows that night topup to 80% is better than my current 75% to 25% charge/discharge cycle, I will stick to my charging regime. The critical factor in when to charge is, will the %SOC allow me to my next days driving, and not fall below 20% when I return home.
 

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You are right that the statement "Daily charging is not meant to be good for the EV batteries" is my opinion, that less you can charge Lithium batteries the better (w/o letting battery go below 20%) .

My charging routine is based various studies I have seen. So what I am saying has been tested in studies, whereas the assumtion that nightly topup (random %SOC to 80%) is good, I can't find any studies that show that.

For example this study, see figure 8.

It shows lower degredation at the same number of charge/discharge cycles, so 75% - 25% is better than 85% - 25%, which in turn is better than 100% - 25%.

I use the car daily and use approx 12% charge per day in my commute, so I charge every 4 days. Till I see a study that shows that night topup to 80% is better than my current 75% to 25% charge/discharge cycle, I will stick to my charging regime. The critical factor in when to charge is, will the %SOC allow me to my next days driving, and not fall below 20% when I return home.
I don't believe anyone should tell you how to treat your car, heck some people think it's ok to never change the oil in their ICE car. But I would suggest you reread this paragraph in the study you site:

"Evaluating battery life on counting cycles is not conclusive because a discharge may vary in depth and there are no clearly defined standards of what constitutes a cycle (see BU-501: Basics About Discharging). In lieu of cycle count, some device manufacturers suggest battery replacement on a date stamp, but this method does not take usage into account. A battery may fail within the allotted time due to heavy use or unfavorable temperature conditions; however, most packs last considerably longer than what the stamp indicates."

Keeping your battery plugged in and at an 80% charge is likely the best thing you can do (and what most EV owners have come to understand over the last 10 years) particularly if you experience temperature extremes because the system will then have power available to keep the battery in the right temperature range. Obviously you have to make the choice for your own car.
 

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@JRRF I never considered temperature extremes, because I live in London, but I guess in the US it is a issue, especially somewhere like Arizona.

What constitutes 1 charge/discharge cycles is not well defined especially for partial charging. Does charing from 60% to 80% for 5 days constitute 1 cycle or 5 cycle?
 

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What constitutes 1 charge/discharge cycles is not well defined especially for partial charging. Does charing from 60% to 80% for 5 days constitute 1 cycle or 5 cycle?
That's a decision we each make individually based on the evidence we feel is most compelling.
 
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