Charging Regimen

[j.w.s]

We have had Opal (our R1T) for nine months. We have been charging her at home on a Rivian wall charger. Our routine is to let her go to about 20% state of charge and charge her up to 70%. This has worked well for our use routine.

Should we continue our charging regimen as is or would it be better for her battery to vary the max charge?

Brian

Our Lithium batts don't mind sitting partially charged, unlike old NiCad batteries. So 20%-70% is OK - actually better than OK; you are being nice and gentle. I do the same.

I do wonder about one thing. Lithium battery "'battery management systems" (BMSs) have a "balancer" function that selectively charges/discharges individual cells so that they don't get out of balance over time. The Rivian has 108 cells I believe. If 107 cells are at 3.862 volts and one is 3.830 volts, the balancer will stuff a little extra charge into that cell to bring the voltage up to match the rest, etc. Balanced.

But typical BMS systems only start working when the charge level is quite high. In other words, unless your battery sometimes gets nearly fully charged, the balancer won't kick in and the cells might become imbalanced over time.

So I wonder if it is "a good idea" to occasionally slowly charge above 90% just to give the balancer some time to work. I suspect that it is, so that's what I do. My protocol is: Recharge every day at home. Daily charge limit of 70%, or 60% if the car will sit idle for some time, and try to stay above 20%. Charge to 90-100% for longer trips and at least once per month for the balancer, but don't let it sit above 90% for more than a few hours before driving. Fast charge only up to 80%, maybe 90% if I really need the range, but never to 100%.

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[Electrified Outdoors]

70-80% is a good limit. Even 85 is ok. We typically charge ours to 80 for daily use. 100 when going on road trips.

 

[md2023]

We have had Opal (our R1T) for nine months. We have been charging her at home on a Rivian wall charger. Our routine is to let her go to about 20% state of charge and charge her up to 70%. This has worked well for our use routine.

Should we continue our charging regimen as is or would it be better for her battery to vary the max charge?

Brian

We normally keep it between 50 and 80% , but definitely get down to 10% sometimes (It gets driven a good amount). I have charged to 100% (or close) probably 5-10 times for longer trips.
And we try to use solar as much as possible so it varies by the amount of sunshine too.

 

[iansriv]

20-70% is a good rule of thumb, as most have stated here. I usually keep it between 50-70% IF I can just in-case I need to go somewhere unexpected-like yesterday. Just went on my first out of town trip and charged to 100%.

 

[defcon888]

We charge "Lapis" (blue R1T) from when I get home from (30%-ish) to 90%. I drive 145 miles to work (1 day a week). We don't drive it that much at home not because we don't want to, it is because we have an RAV4 Prime that gets 45 miles on a charge which is what we call our "grocery getter".

I drive to work on ALL-Purpose and drive home on Conserve. It helps the tire wear

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