Speak EV - Electric Car Forums banner

1 - 12 of 12 Posts

·
Registered
2018 e-Golf
Joined
·
727 Posts
Discussion Starter #1
Just wondering whats best for my battery?

I have my max charge set to 80% and i can probably do my daily commute 3-4 times on that.

Is it better for the battery to do 3 days runs to work and back before charging or can i plug it in every night?
 

·
Super Moderator
Joined
·
7,505 Posts
With the 80% limiter switched on my advice would be yes to charge it each night. The smaller the SOC window you use the better.
 

·
Registered
Joined
·
4,791 Posts
Since plugging and unplugging is extra hassle and more wear and tear on the connectors I'd only do it every few days. But I'd never let it go lower than a couple of days use (in case of forgetting to charge or unexpected journeys).
 

·
Registered
Joined
·
17,363 Posts
It would make little difference to you unless you are planning to keep the car for 20 years. Even then it’s probably in the noise of the different degradation rates.

Just enjoy the car and learn to stop worrying about SOC.

(Reminds me of people that were paranoid about keeping the petrol tank half full so the fuel pump didn’t ‘pick up dirt from the bottom’). :)
 

·
Super Moderator
Joined
·
7,505 Posts
It would make little difference to you unless you are planning to keep the car for 20 years. Even then it’s probably in the noise of the different degradation rates.

Just enjoy the car and learn to stop worrying about SOC.

(Reminds me of people that were paranoid about keeping the petrol tank half full so the fuel pump didn’t ‘pick up dirt from the bottom’). :)
Fair enough..... but...... my Leaf is 9 years old and down to 60% battery health. If I'd treated it nicer and used the 80% setting all this time I think that health would be a lot higher......
 

·
Registered
Joined
·
925 Posts
As the BMS leaves a buffer at both the top and bottom of around 10%, you're reasonably ok, try not to discharge below an indicated 10% regularly and if you have an 80% max charge setting use that unless your're going on a long journey and you'll be looking after your battery. Doing this roughly doubles the life of the battery.
 

·
Registered
Kia e-Niro MY20 64 kWh - Gravity Blue
Joined
·
268 Posts
As the BMS leaves a buffer at both the top and bottom of around 10%,
Please explain which car has a battery with a 20% buffer?

I think in general you're looking more at 5% - 10%. The Kona / e-Niro have a 64 kWh battery with an estimated gross capacity of 67 kWh. The 58 kWh ID3 has 62 kWh gross. The PSA siblings have a 45 kWh battery with a gross capacity of 50 kWh. 20% buffer I think you'll only find in the Volt / Ampera.
 

·
Registered
Joined
·
925 Posts
The 22 kWh Zoe is thought to have a 26 kWh battery which is almost a 20% buffer, Granted many of the later cars have a lesser buffer. The battery capacity varies with the maximum and minimum allowed voltages per cell, so it's possible the manufacturers have already left a buffer in their stated capacity for the cells, my point was really that there is already a buffer that has been left to protect the battery, but leaving a little more at the top and bottom when you can is a way of minimising the degradation.
 

·
Ampera aka IGOR
Joined
·
3,495 Posts
Personally irrespective of the SOC setting in the car, I would be keeping it plugged in so that, if needed, the car can heat or cool the battery depending on the weather without using battery power. I could be wrong but my understanding is that extremes of weather are every bit as bad for a battery as keeping it fully charged, happy to be corrected.
 

·
Registered
Joined
·
17,363 Posts
Personally irrespective of the SOC setting in the car, I would be keeping it plugged in so that, if needed, the car can heat or cool the battery depending on the weather without using battery power. I could be wrong but my understanding is that extremes of weather are every bit as bad for a battery as keeping it fully charged, happy to be corrected.
This only happens if the car is turned on. Also, only really a problem if you need to drive when the temperature is over 40 or under -10 degrees. :)
 

·
Registered
Joined
·
343 Posts
Unless your home chargepoint is a rapid 50kWh unit....is there really anything to be concerned with?
Is it considered NOT okay to charge daily (if you want)? Does the battery degrade significantly?

I read (example here) that using the rapids regularly can damage the batteries, but I am also conscious (for example) that Hyundai give an 8 year warranty on their batteries.
We plug ours in perhaps every other day on average.
 

·
Registered
Joined
·
147 Posts
Sounds like you are doing the right thing setting the max charge to 80%. I understand that batteries degrade most at >80% and <20%. You would get a warning with your service report if you keep doing small recharges to 100%, i.e. charging every day after a small commute but I assume it isn’t a problem to do small recharges to 80%. On that basis it’s probably ok to charge every day or let the battery go through a fuller cycle, just not below 20% too often.
Of course it is another debate as to whether thats 20-80% do displayed capacity or actual capacity!
 
1 - 12 of 12 Posts
Top