85kwh Battery Opinion

[random155]

Looking for opinions on the status of my 2014 MS85. About 62000 miles on it. Tried getting to 100% but ran out of time before having to leave for dinner. My last attempts, several months ago, to charge to 100% car said charging complete at 98% and would not go any further. My volts on my packs are about 4.18. Does that mean my pack isn’t battery gate?

 

[random155]

Sorry about pics and not screenshots. Androids...

 

[Lasttoy]

My buddy at SC told me to plug it into 110v to get it full to 100 percent.

 

[random155]

My buddy at SC told me to plug it into 110v to get it full to 100 percent.

Thank you sir.

 

[Electric700]

Try not to charge to 100% if you can avoid it. 80 - 90% is better. Tesla told me the battery should automatically balance even when charging to 90%.

If you are taking a trip and really need to charge to 100%, you should drive immediately after the charge completes.

 

[LoudMusic]

There's a thread somewhere that I now can not find, but they talk about getting the display to show correct miles available and correct percentage. Mostly they encourage owners to allow the vehicle to balance at different states of charge so that the computer can get a much better idea of what the condition of the battery is.

Apparently it only balances when the car is 'asleep', which it only does when it has sat for several hours unplugged and unused, sentry mode of, etc. So the recommendation, by owners NOT Tesla, is to let it sit overnight at 10%, 20%, 30%, etc, and see if the displayed values are more what you expect after completing that long process of balancing.

But yes, everyone agrees it shouldn't be charged to 100% unless you are anticipating to leave immediately after charging.

 

[random155]

Thanks for the input. I am aware about not charging to 100% daily. I havent charged to 100% in over a year, but when I wanted to get as much juice as possible for a long trip, the battery wouldnt take more than 98%. Tesla is actually telling me that to balance the battery, I need to charge to 90% and leave it plugged in for hours daily, and to do this for 30-90 days. This as in lieu of a service center appointment to figure out the issue. They remote diagnosed a small imbalance and looked at charging habits to determine this remedy.

 

[LoudMusic]

Initially I had see/read that Tesla recommended if you're not driving the car to plug it in. But that seems to not be the recommendation anymore - at least not from owners.

 

[random155]

Initially I had see/read that Tesla recommended if you're not driving the car to plug it in. But that seems to not be the recommendation anymore - at least not from owners.

Understood. This is my message from Tesla:

Hello Dan, A technician has completed a diagnosis of your concern and provided the following results; The customer has a slight battery cell SOC imbalance. Looking at the vehicle the customer lowered the charging termination percent to 90% and allowed the vehicle sit connected to the charger for approx. 5 hours. After this we see the imbalance begin to close however while this is the correct method to rebalance a vehicle the amount of time allowed (once for 5 hours) is insufficient in length of time. The process below needs to be repeated every day for 30-90 days and for as long as possible each day. Deep discharging will only increase the range estimate in miles and will not influence the batteries capacity or cell balance. Let the vehicle rest at 90% SOC. Set the charge slider to 90%. Keep the vehicle plugged in for several hours after it reports a complete charge and says it has stopped charging. This will cause the pack to rebalance.

2:37 p.m.

 

[beatle]

It's interesting that the pack will rebalance at 90%. I thought it didn't start until 93%, but maybe that's just how it used to be.

My guess is that leaving the car plugged in prevents it from accidentally fully draining (say, you forget about the car or otherwise cannot get to it to plug it in for a long period of time) and to allow it to balance at a higher SoC.

 

[random155]

It's interesting that the pack will rebalance at 90%. I thought it didn't start until 93%, but maybe that's just how it used to be.

My guess is that leaving the car plugged in prevents it from accidentally fully draining (say, you forget about the car or otherwise cannot get to it to plug it in for a long period of time) and to allow it to balance at a higher SoC.

Yeah kind of weird. Its kind of annoying to always have it plugged in, but I'll try it for a month and see if I can get up to 100%

 

[beatle]

Seems like a good reason to always have your SoC set at 90% so that it balances every time it completes a charge.

 

[Droschke]

Understood. This is my message from Tesla:

Hello Dan, A technician has completed a diagnosis of your concern and provided the following results; The customer has a slight battery cell SOC imbalance. Looking at the vehicle the customer lowered the charging termination percent to 90% and allowed the vehicle sit connected to the charger for approx. 5 hours. After this we see the imbalance begin to close however while this is the correct method to rebalance a vehicle the amount of time allowed (once for 5 hours) is insufficient in length of time. The process below needs to be repeated every day for 30-90 days and for as long as possible each day. Deep discharging will only increase the range estimate in miles and will not influence the batteries capacity or cell balance. Let the vehicle rest at 90% SOC. Set the charge slider to 90%. Keep the vehicle plugged in for several hours after it reports a complete charge and says it has stopped charging. This will cause the pack to rebalance.

2:37 p.m.

@random155 , Questions:

1) Do you happen to have the draingate issue? (when charging beyond 70-80% triggers the cooling pumps to run for hours resulting in loss of miles added during the previous charging session)
2) Has your battery capacity been capped by Tesla?
3) Have you seen any miles gained by practicing what the SC has recommended?

 

[random155]

@random155 , Questions:

1) Do you happen to have the draingate issue? (when charging beyond 70-80% triggers the cooling pumps to run for hours resulting in loss of miles added during the previous charging session)
2) Has your battery capacity been capped by Tesla?
3) Have you seen any miles gained by practicing what the SC has recommended?

I do have the pump draingate issue. My battery nominal full pack is 73.8 kwh and a 4 kwh buffer (not sure if that qualifies as batterygate. I have not seen any additional miles since starting this process, however Im only a few days into it.

 

[Droschke]

I do have the pump draingate issue. My battery nominal full pack is 73.8 kwh and a 4 kwh buffer (not sure if that qualifies as batterygate. I have not seen any additional miles since starting this process, however Im only a few days into it.

Thanks for your reply. Having 73.8 puts you at 9.4% (i.e., 1-(73.8/81.5)) capacity loss since the car was new. I'm at 12% and am batterygated.

At what SoC% your pumps start to kick in, how long they stay on till stop, and how many miles they shed off your 90%? Any idea?

Thanks.

 

[random155]

Thanks for your reply. Having 73.8 puts you at 9.4% (i.e., 1-(73.8/81.5)) capacity loss since the car was new. I'm at 12% and am batterygated.

At what SoC% your pumps start to kick in, how long they stay on till stop, and how many miles they shed off your 90%? Any idea?

Thanks.

No, Ive never really paid too much attention to that.

 

[Droschke]

No, Ive never really paid too much attention to that.

Please keep us posted here on your progress.

 

[beatle]

I think the cooling pumps run excessively on all cars now, but maybe I'm wrong.

Check your cell voltage at 100% charge. The cells should read around 4.2v each.

I found that anything over 73% will trigger the pumps to run. I think they go for about 3 hours.

 

[Tomilett]

if you want to achieve actual 100% turn the cabin heating (& battery heater) on at c.96% and leave it on while it completes charging. my battery will only ever get to somewhere between 97% and 99% if the heater isn't on, and for some reason the BMS doesn't have the ability to turn on the battery heater (to the same extent as preconditioning can) as 100% is approached. Also once it's decided it's complete at say 97%, there is nothing you can do to make it finish (e.g. by turning on the heater, unplugging and plugging in again, adjusting % slider down and then up again - nothing!) so you absolutely have to catch it during charging and a few % below 100. In my case if I manage that it will always go all the way to 100% and if I don't it will never make it. Obviously try not to do it too often, but it is useful to get actual 100% sometimes.