The "minimum battery workout per week" topic

Hi - I drive a 2017 Nissan Leaf SV that hits the three year mark on August 1, and has 8,801 miles on it as of this writing.

Given that I'm NOW driving almost not at all, AND I BELIEVE I've read from folks like Dave in Olympia (?) that EV batteries need 'workouts' just like us humans do, I'm wondering:

Q: Is there a consensus on the MINIMUM miles I should be driving each week in order to maintain battery health?

Is there also a minimum number of miles I should target for each individual drive?

My typical errand-based journey runs anywhere from 2 to 5 miles, round trip.

Thank you.

No. Never heard of any.

Just recommend not being at high SoC for extended periods of time, esp. in hot weather.

From looking at Leaf Spy, it looks like my Leaf has moved about 200 miles in the last 4 months due to not driving to work (due to lockdown and county health orders, work policy, etc.) and mostly driving my Bolt when I do drive (long story).

My '19 Bolt (bought end of Jan 2019) is only at 9,752 miles right now. From Onstar emails vs. current stats, looks like my Bolt has moved about 1000 miles between end of March and now.

I have several thousand fewer miles on my 2018, and the lack of driving doesn't seem to have harmed the battery. Or helped it.

SOH from LeafSpy or similar tools is the car's estimate of battery state of health.

SOH is an estimate, not a measurement.

The SOH estimate can be increased by various things that clearly or likely don't have any actual benefit to the real state of health of the battery.

The SOH estimate can be lowered by various other things that clearly or likely don't have any actual harm to the real state of health of the battery.

Thanks, Wet, for reminding us, once again, that Life Is Just a Dream. Or maybe a simulation. So, to slightly garble an old radio admonition, "Don't trust that dial!"

Thanks all. So it seems like I can drive as little as 10-12 miles per week for the next year, and this should have no negative impact.

Awesome.

Stupidly expensive on a per mile basis, but awesome.

The issue you are most likely to have is a low 12 volt accessory battery. If you can't top it off with a little battery maintainer or an external charger once a month (I'm about to hardwire mine for that) then try running the car for 1/2 an hour every week or two in Ready mode, with climate control on. You don't have to actually drive it.

Interesting. Thank you, Leftie!

I can drive around for 30 min per week. Climate control? OK, if I have to.

RapmasterD said:

Interesting. Thank you, Leftie!

I can drive around for 30 min per week. Climate control? OK, if I have to.

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You can just start the car and leave it where it is if you don't want to go on the road.

The Leaf will charge the 12 volt battery with more voltage in climate control mode, or at least that's what some have found here. Driving the car is unnecessary because unlike an internal combustion engine with an alternator, it doesn't need for the "engine" to be spinning to provide power. That comes from the DC-DC converter, which takes high voltage DC from the pack and converts it to roughly 13-14 volts DC (thus the name).

If I put a subwoofer in the Leaf and used THAT instead of climate control in ready mode, would THAT have similar impact as using climate control?

Yes, this is a serious question.

Thank you.

RapmasterD said:

Hi - I drive a 2017 Nissan Leaf SV that hits the three year mark on August 1, and has 8,801 miles on it as of this writing.

Given that I'm NOW driving almost not at all, AND I BELIEVE I've read from folks like Dave in Olympia (?) that EV batteries need 'workouts' just like us humans do, I'm wondering:

Q: Is there a consensus on the MINIMUM miles I should be driving each week in order to maintain battery health?

Is there also a minimum number of miles I should target for each individual drive?

My typical errand-based journey runs anywhere from 2 to 5 miles, round trip.

Thank you.

Click to expand...

Just a point of clarification; I didn't suggest you need to exercise your pack only that very high mileage drivers exceed the curve by a huge margin partially because they are beating Father Time which is also an unavoidable factor in the degradation game.

BUT...there are things you can do to help your case and that is SOC management. With your modest driving needs, this should be very easy for you. Simply don't charge past 50% SOC.

If you live in warmer areas, an even lower SOC would be better but as ALWAYS my #1 rule for battery management is the same for everyone.

Do not overcharge your car. If you drive every day but only charge twice a week, you are overcharging.

If you get home at night after a day that went as you expected it to go and you can repeat that day w/o charging then you overcharged.

You might think 80% SOC is ok but if you only need 20% of it, then you are overcharging.

Thanks for weighing in, Dave! And also, thx for the clarification.

I was actually planning on adopting a 60% to 40% routine. But do you think it’s notably better to go 50% to 30% or 50% to 40%?

Thank you.

RapmasterD said:

Thanks for weighing in, Dave! And also, thx for the clarification.

I was actually planning on adopting a 60% to 40% routine. But do you think it’s notably better to go 50% to 30% or 50% to 40%?

Thank you.

Click to expand...

There was actually a rather surprising study published where there is strong indications that maintaining the car at the lower ends of the SOC spectrum is more beneficial. I guess I have to say that all my time living with the "blinking" bar was helping me in ways I didn't know

https://www.mdpi.com/2076-3417/8/10/1825/htm?fbclid=IwAR1aXHm2sfKh34NhUDBK4sxs5Z0NJ_TVia77zll2qur-bJqBv-bAdm2TzAI

The article is rather technical so if you aren't willing to wade in, here is the key takeaway

"The result showed that, when only considering ageing from different types of driving in small Depth of Discharges (DODs), using a reduced charge level of 50% SOC increased the lifetime expectancy of the vehicle battery by 44–130%. When accounting for the calendar ageing as well, this proved to be a large part of the total ageing. By keeping the battery at 15% SOC during parking and limiting the time at high SOC, the contribution from the calendar ageing could be substantially reduced."

IOW; even if only charging to 50% SOC, you still want the charge to finish shortly before you drive.

I've known about the concept of keeping below the 50% SOC. Range anxiety has kept me from trying to do this. I'm now going to try it out.

I have a Level 2 charger, so IF I know I'll need to drive greater than 40 miles in a day, I'll simply do a (quicker) level 2 charge.

Will this infrequent (?) use of the higher charging speed be detrimental to the battery, and negate any benefit of longer periods less than 50% SOC?

gncndad said:

I've known about the concept of keeping below the 50% SOC. Range anxiety has kept me from trying to do this. I'm now going to try it out.

I have a Level 2 charger, so IF I know I'll need to drive greater than 40 miles in a day, I'll simply do a (quicker) level 2 charge.

Will this infrequent (?) use of the higher charging speed be detrimental to the battery, and negate any benefit of longer periods less than 50% SOC?

Click to expand...

Well, there is the time issue which means infrequent use of the car will increase your overall costs since it is a depreciating asset but imm, its low hanging fruit and not a major consideration.

It has me mulling over my charging habits. During the work week, I simply don't really have time for any major detours and I have been running my SOC between 30 to 65%. Looks like I need to reevaluate that option which would have been easy but I am being evicted so moving to a place yet undetermined but not likely to have charging of any type which means all public charging and I won't be doing that on a daily basis so...

Thank you for the article link, Dave. I’ve learned more in the last three weeks about the Leaf battery than I have in the past three years.