Every time I charge at home…

[Aardvark]

Come on, folks. Everyone knows you have to leave room for expansion when the electrons heat up. ?

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[Robin]

It’s not 69, “you do me and I’ll owe you one”. It’s 69.999999999, which is closer to Eh, Yeah, I’m done…...

Ditto on the 69

??‍???

 

[jplblue]

I'm seeing the same issue. I set the truck to charge to 50%, it ended at 47% or 46% - same screen says both. Something strange afoot...

Same for us -- set to 50% and charges to 47%. Do you set a charging schedule at night? It's something we started doing recently and trying to figure out if that's the cause.

 

[Count Orlok]

The Count says always charge to 77% because you get ate more...

 

[Wilson]

I don’t think it is a phantom drain, rather just how it is coded/programmed, it stops at 69.51% and then when it drops by .02% (powering wifi / sleep mode / sensors) it says 69% (rounded from 69.49%).
¯\_(ツ)_/¯

 

[shandel]

I have mine set to charge to 70% every night. According to my Electrafy data, it charges to 69.9% (shows 70% in the app) and then over the next hour loses 0.7% and lands at 69.2%, which the app shows as 69%. I'm not sure if it's actually losing 0.7% or what, but by the time I wake up and check it's consistently at 69% and remains there for the rest of the day if I'm plugged in. If I'm unplugged then I'll get some more phantom drain throughout the day and land somewhere in the 68-67% range.

 

[jbssfelix]

Nice.

 

[R.I.P.]

When you feed your Jeep with 92 octane petrol, you are not getting absolutely positively the exact amount the pump bills you for. You may be one drop over or under the 10 gallons that the pump reads. There is a lot of "ish" in the real world.

Many years ago this caused Ford to stop giving its customers exact readings on some of the instrumentation. Too many people were too focused on if the needle was just slightly high or slightly low, and it caused Ford too much overhead investigating stuff that was not broken. Instead, they went to gauges that just sat in the middle if they were within intolerance.

In the end, this is not really to the benefit of the customer. A great many of us actually do want to see if the needle is climbing slightly or drooping because it can foreshadow issues that we can then address.

I would certainly hope that there are not people putting in service tickets because the charge goes to within one or two percent of what they set it. If you actually understand the chemical process, hitting the _exact_ number and keeping it there is an unreasonable expectation. But if enough people complain, we're going to start getting "ish" readings again, which is not to our benefit.

Stated another way, rejoice that you are getting precise measurements. If you complain about this gift, it may be taken away from you.

 

[edman007]

Agree, if you look at the data from the API, it charges up to the set point, then stops, and usually vampire drains slowly. If it's cold enough it might condition the battery and charge it back up.

Also, I think the battery temp does affect the reading, understand the BMS is calculating percentage based off the information it knows, there isn't a thermister inside every cell, so the BMS doesn't have a perfect idea of the temperature. Voltage depends on temperature, so I think the BMS will see the voltage fluctuate as the temperature changes and interprets it as a different SoC.

 

[R.I.P.]

Agree, if you look at the data from the API, it charges up to the set point, then stops, and usually vampire drains slowly. If it's cold enough it might condition the battery and charge it back up.

Also, I think the battery temp does affect the reading, understand the BMS is calculating percentage based off the information it knows, there isn't a thermister inside every cell, so the BMS doesn't have a perfect idea of the temperature. Voltage depends on temperature, so I think the BMS will see the voltage fluctuate as the temperature changes and interprets it as a different SoC.

Absolutely correct, you cannot put thermistors inside the cell; but each cell better have one attached to it! How many thermistors is that all sending data to the computer to calculate an average? How many is that in constant flux making that average a constantly updating figure?

You present a great example of just one of dozens of variables that are used to make a guess at what's inside your ion tank. That guess can easily be 10% off at any given time if you were to have access to absolutes in the data.

In fact, modern BMSs are doing a remarkable job of making these guesses. But in the end, seriously, it is just a guess.

 

[defcon888]

Always set to 70%. 12-6am schedule. I’m starting to think someone at Rivian is perverted ?

I have mine set to 90% (long commute) and it tops off at 89%.

 

[HaveBlue]

This is what they call a charge limit. Charge to 70%. It's akin to driving your Rivian to a wall or driving your Rivian through a wall.

 

[MILamm]

Always set to 70%. 12-6am schedule. I’m starting to think someone at Rivian is perverted ?

Doesn’t that red lightning bolt with the red slash indicate a charger error. My new home charger is showing me that same symbol when I leave it plugged in a few days. When it tries to restart charging due to battery leakage, it gives me an error and won’t restart unless I unplug and replug

 

[Redline]

Doesn’t that red lightning bolt with the red slash indicate a charger error. My new home charger is showing me that same symbol when I leave it plugged in a few days. When it tries to restart charging due to battery leakage, it gives me an error and won’t restart unless I unplug and replug

It happens daily but doesn’t do anything. I have a special program with my electric company for 12-6am charging at $.028 kWh. At first I only had the schedule in the charger and it didn’t work right. Now I have it in the car and charger and it works. The error comes up but it still charges every time ?‍

 

[MILamm]

It happens daily but doesn’t do anything. I have a special program with my electric company for 12-6am charging at $.028 kWh. At first I only had the schedule in the charger and it didn’t work right. Now I have it in the car and charger and it works. The error comes up but it still charges every time ?‍

I have been away for a month, and since I’m not unplugging it daily, the battery is draining and not getting recharged due to that error symbol. I don’t have the program in my vehicle yet and will try that when I get home

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