[Bop2300]

Just wondering, should I Always charge my R1T to 70% or should I mix it up once on a while? I'm retired and don't to get far every day, so I usually wait to it's down to 50% and then charge to 70% probably every other day. I don't want to lose the top end of the battery by not using it at all.
Thanks,
Tony

 

[racekarl]

I would not stress about it too much. Lithium batteries don't develop "memory" the way older NiCad or NiMH batteries did, so you're not going to "lose the top end" by never charging it to 100%.

The thing that Lithium batteries really dislike is being over-discharged, so most EV makers put in a "false floor" so that 0% reported battery capacity actually means that the batteries are at 5% or 10% charged. I am 90% confident Rivian has done this (it's part of the reason EV makers are sometimes cagey about the actual usable capacity of the battery).

Lithium batteries also don't like sitting for long periods of time at 100% charged (but not as bad as being at 0%) so EV makers either build in a false ceiling to go with the false floor or they make it clear in the car's charging UI that you normally charge to less than 100% as Rivian does.

Edited to add: sometimes the battery control software can become confused about the capacity of the battery if you don't use the battery over a larger range of SoC. You sometimes see advice to "reset" its understanding of the battery by charing to 100% then discharging to close to 0%, but it does not really affect the life of the battery itself, and I have no idea if this advice applies to Rivian

 

[Bop2300]

Thank you for the great read, I just learned something.
TY racekarl

 

[atebit]

AFAIC, “A happy BEV is a plugged in BEV”. Plug it on & let the BMS sort it out.

 

[Matty]

My truck is going to be parked for 4 months each year, leave it plugged in? Or have someone plug it in periodically?

 

[CommodoreAmiga]

My truck is going to be parked for 4 months each year, leave it plugged in? Or have someone plug it in periodically?

Leave it plugged in to a L2 EVSE.

 

[Matty]

Thanks.

 

[empickle]

Edited to add: sometimes the battery control software can become confused about the capacity of the battery if you don't use the battery over a larger range of SoC. You sometimes see advice to "reset" its understanding of the battery by charing to 100% then discharging to close to 0%, but it does not really affect the life of the battery itself, and I have no idea if this advice applies to Rivian

The Tesla Model S does a good job of measuring the voltage of individual cells and, by all reports, can be plugged in. The Model 3, however, muxes through the cells to measure them and is more statistical. We were plugging ours in every night for the first couple years, because Always Be Charging, and found we lost a lot of range. However now we run it down from 80 to 25% and back and haven't lost much range at all.

My guess is that Rivian has more of a Model S design pattern if only to gather more data on their charging algorithms. But that's just a guess. Rivian hired (paywall) a lot of former Tesla engineers.

 

[Tomgriff]

I would follow the Owner's Manual:

I don't charge to 100% with either of my other EVs per their manufacturer's guidance. Also if you charge to 100% you can no longer regen (one-pedal drive won't stop you) until you drive a bit and there is room in the battery for the regenerated energy to go.