Volvo XC40 Forum banner

What charge limit do you typically use?

  • 100%

    Votes: 2 5.6%
  • 90%

    Votes: 20 55.6%
  • 80%

    Votes: 12 33.3%
  • 70%

    Votes: 1 2.8%
  • < 70%

    Votes: 1 2.8%
1 - 20 of 22 Posts

·
Registered
2021 XC40 P8 - Onyx, 01/21, v1.6
Joined
·
24 Posts
Discussion Starter · #1 ·
Curious what everyone uses as their day-to-day charging limit.
 

·
Registered
Joined
·
1,678 Posts
I have 90 set as my limit and if I am away doing stuff (green lots at the park or topping up at qfc this is what I charge to. Other than that I feel comfortable as long as the car has over 20%. Often it hovers around the 50s going up when I charge whilst doing and down when I use.

I am really surprised at how little range stress I have. Wish I could charge at home but that will happen when the house market goes sane.
 

·
Registered
Joined
·
1,678 Posts
Gotcha. I was planning on 80 but Volvo stated 90 is good and they are very conservative so I felt safe setting limit to it. Most of the time though it does not get to get to 90.
 

·
Registered
2021 XC40 Recharge
Joined
·
154 Posts
My weekday charging is only to 60% and I let is go down to 40%.
If you regularly charge to less than 90% like I do, it is good to charge up to at least 90% every month or so to allow the car to balance the batteries. Otherwise, your range may degrade over time because the individual batteries diverge in level.
 

·
Registered
Joined
·
1,678 Posts
My weekday charging is only to 60% and I let is go down to 40%.
If you regularly charge to less than 90% like I do, it is good to charge up to at least 90% every month or so to allow the car to balance the batteries. Otherwise, your range may degrade over time because the individual batteries diverge in level.
Do we know for sure the batteries fill in a linear way? I would imagine that which cells are used are abstracted and the use over time is shared similar to a ssd. I would be shocked if they filled from the bottom up as your reply would indicate.
 
  • Like
Reactions: John M

·
Registered
2021 XC40 Recharge
Joined
·
154 Posts
Do we know for sure the batteries fill in a linear way?
How did you extract that out of what I said? Of coarse not. But, the result of the formula which calculates SOC is intended to be linear and presented to us as a percentage.
The important part to understand is that when the SOC reads a value like 60%, not every single cell is going to be at the equivalent charge of 60%. Some cells may be lower or higher until the battery management system (BMS) is allowed to rebalance the cells. Now, I don't actually know when Volvo BMS performs a rebalance. Tesla has mentioned it to happen >= 90% which makes sense so that charging is as fast as it can be from 0-90%.

 

·
Registered
Joined
·
1,678 Posts
How did you extract that out of what I said? Of coarse not. But, the result of the formula which calculates SOC is intended to be linear and presented to us as a percentage.
The important part to understand is that when the SOC reads a value like 60%, not every single cell is going to be at the equivalent charge of 60%. Some cells may be lower or higher until the battery management system (BMS) is allowed to rebalance the cells. Now, I don't actually know when Volvo BMS performs a rebalance. Tesla has mentioned it to happen >= 90% which makes sense so that charging is as fast as it can be from 0-90%.

Nice data thank you. Would there not also be a variable discharge per cell rate as well allowing balancing to happen on use as well as on charge?

A side question. Can the battery pack get itself into a condition where the maximum power output is lower than normal max as some cells are getting low / discharged? For maximal power how many cells have to max their output? Could a combination of keeping the charge low but driving hard result in a temporary decrease in max performance until a larger % charge and re balancing happens?

The delightful complexity’s of ev power vs ice :)
 

·
Registered
Joined
·
1,138 Posts
I set it to 90% day one. I do not top off everyday either. Initially I would run down from 90% to about ~50% and lately down to about 40-45% depending on what I think my needs will be over the coming 1-2 days. Battery life is a combination of min/max battery swings and cycles. I figure minimizing the number of cycles makes up for going to 90% vs. the more common 80% for optimal life.
 

·
Registered
2021 XC40 Recharge
Joined
·
154 Posts
Would there not also be a variable discharge per cell rate as well allowing balancing to happen on use as well as on charge?
I imagine so, but I don't know if it is significant enough to worry about except those that are into racing EV's.

Based on Bjorn's acceleration tests, it's clear that a low SOC will have a reduction in performance. But, I doubt the difference between cells ever gets to be that large of a difference.

1189
 

·
Registered
‘22 XC40 Recharge Twin in Denim Blue
Joined
·
12 Posts
Dealer told me at purchase to charge only to 80% unless I was planning a long trip.
I‘m reading here some folks charge up to 90%.
Can anyone confirm the actual recommendation from Volvo?
I did see in the manual a schedule option but I can’t seem to find it anywhere.
 

·
Registered
Joined
·
1,138 Posts
Volvo recommendation is 90%, although honestly 80% is likely safer for longevity. What I fond is even on home charger the charge rate to 80% is fast, the 8-90% a little slower. VW and I believe Tesla recommend 80%. If you are charging frequently and just doing short daily runs then 80% is better. I use 90%, but have been considering 80% as I only have been charging once a week on average and run down from 90% to ~40% so going to 80% still gives me room and I can always charge more frequently.
 

·
Registered
Joined
·
16 Posts
90% But also I don't drive that much so I only charge about twice a month or less. The only time I charge more is when I travel off and on which doesn't happen much. When I take my dogs out I use my Jeep JKU so I don't use the EV for that. Right now, for example, my XC40 is at 85+% and I've not charged or driven it in several days.
 

·
Registered
Joined
·
1,678 Posts
Volvo says 90. The screen confirms this but if you are charging at home and not going on a long trip you could do 80 to hedge your bets. When I have time to charge to 90 I do 90. As often I give up and skip out somewhere 70 to 80. That said car has a long drive to a funeral this weekend so it is at 94 now so it can go there and get back 210 miles.

Honestly Dealers are the worst source of information :( half the time I swear they use a modified magic 8 ball …
 
  • Like
Reactions: revpixel

·
Registered
2021 Glacier Silver XC40 Recharge P8
Joined
·
114 Posts
I found this article to be quite enlightening and have been doing the 20%-80% range, unless I have long trip the next day when I will charge up to 90 or 100%.
 

·
Registered
Joined
·
155 Posts
I think if Volvo says 90% you are safe at 90%, after all they do have a battery warranty for 8 years/100,000 miles*. I don't think we know if they have a hidden buffer you can't touch. The degradation experienced from charging fully frequently is unlikely to make a difference in the resale value as EVs with smaller batteries become more common and the charging infrastructure is built out.

That being said, charging past 80% is slower and uses more energy so there is no reason to do it unless you need the extra range.

*I think some of us will hit that 100,000 miles, but 8 years is going to feel like an eternity for most people who bought a bleeding edge car in 2021.
 
1 - 20 of 22 Posts
Top