Impossible to hurt current 70D locked battery?

[Three60guy]

Greetings:

First, let me say I am proud to join your club. Next week I take ownership of a 2016 Tesla Model S 70D with a 75 KW battery in it. I was one of the lucky ones to order a 70D prior to Tesla changing back to a 60D. I was given the option to unlock my 70D and turn it into a 75D but declined to do so due to the lack of value vs price.

The reason for my number one posting is to ask a fundamental question and to ask for some information.

The fundamental question has to do with charging a battery which has been locked to a lower capability than the installed battery has the ability to perform at. Because I can allegedly never reach a 100 percent charge on the 75 kw battery that will be installed, I am wondering if I always charge to 100 percent (to 70kw) how could I possibly hurt the battery and risk longevity issues? Even at the displayed 100% I will not be attaining the real 100% limits of the 75kw battery. Does anyone have any insights into this?

The request for information is to ask anyone with a real 70kw battery as well as a real 75kw battery to please share the voltage readings they get when they are at 100%. That way we can observe from those who have those readings what my Model S is actually doing. If I get readings equating to that of a 75kw battery then Tesla is locking out the bottom charge portion of the battery. If the readings equate with those of a 70kw battery then they are locking out the top of the battery charging function. Either way, we can all learn how Tesla is dealing with the lock out battery policy vs the technical methods they use.

Again, I can not wait to get my new Model S. I also look forward to many interactions with this group. I have already learned a ton from reading this forum.

Cheers

 

[Three60guy]

Yikes!! Looks like I stumped the forum? Over 100 views and no responses? What now? LOL

 

[NOLA_Mike]

Yikes!! Looks like I stumped the forum? Over 100 views and no responses? What now? LOL

I think the answer is we don't know (yet). When you charge to 100% displayed Rated Range (theoritical 70 kWh in your case) how do you know you are charging to 93.3% of the battery's physical capacity? I don't think we know whether Tesla software limits the battery at the upper end or the lower end - meaning it's possible 100% is really 100% and the software just disallows uage of the bottom 7% of the battery.

I think it's logical to assume what you stated is true but one could make an argument that it's most detrimental to the battery to be left at very low states of charge for extended periods of time so maybe they reserved the bottom end. I would be reluctant to do what you propose without confirming what's going on with the software limitation and the battery.

Mike

 

[stopcrazypp]

I think the answer is we don't know (yet). When you charge to 100% displayed Rated Range (theoritical 70 kWh in your case) how do you know you are charging to 93.3% of the battery's physical capacity? I don't think we know whether Tesla software limits the battery at the upper end or the lower end - meaning it's possible 100% is really 100% and the software just disallows uage of the bottom 7% of the battery.

I think it's logical to assume what you stated is true but one could make an argument that it's most detrimental to the battery to be left at very low states of charge for extended periods of time so maybe they reserved the bottom end. I would be reluctant to do what you propose without confirming what's going on with the software limitation and the battery.

Mike

Right, it had never been confirmed that the software limited 70s have the limit on the top or the bottom. The same question was asked of the new 60 in another thread and there is no definitive answer. We know the 40kWh locked out the top, so it makes logical sense for Tesla to do the same here, but no one can say for certain until someone empirically determines if that is the case.

 

[NOLA_Mike]

It seems to me that the most logical thing, since the battery is least happy at both extremes, would be to lock it down in the middle. 3.5% off the top and 3.5% off the bottom.

But that is a fairly simplistic analysis on my part and I'm sure they have good reasons for doing what they do...

 

[stopcrazypp]

It seems to me that the most logical thing, since the battery is least happy at both extremes, would be to lock it down in the middle. 3.5% off the top and 3.5% off the bottom.

But that is a fairly simplistic analysis on my part and I'm sure they have good reasons for doing what they do...

I remember from the 40kWh threads that the reason why the top makes sense is because they already have the charge limit slider and this would be a simple extension of that. If they do both top and bottom, then they have to redesign special software to compute the capacity based on that, rather than having something that is consistent already.

 

[chillaban]

Right, the concensus here seems to be that nobody knows for sure. I am guessing there's some detective work that can be done based off how the supercharging curve levels off when charging to 100% on a 60/70, but that's yet another educated guess...

Service Centers don't see to have a consistent answer either. Someone here was told with their 60D that they can charge it all the way up all the time. I was told by both my delivery specialist and the ServiceHelpNA email hotline that regardless of software or hardware battery capacity limitations, they recommend charging only to the daily range for daily driving.

 

[Canuck]

I would be interested in knowing what the charging slider looks like in your car. Maybe the daily driving range will end at 100% in which case your question will be answered. Please let us know when you get your car.

 

[chillaban]

I would be interested in knowing what the charging slider looks like in your car. Maybe the daily driving range will end at 100% in which case your question will be answered. Please let us know when you get your car.

I've got a software locked S70D, and the slider as well as the Remote S app agree that the charge range goes from 0% to 100% with daily range at 90%. So it does seem like the lock (err, faked out capacity) goes to a deeper level below the UI. I would expect the same to hold true for the 60.

 

[Three60guy]

chillaban:

Do you recall what the voltage you observed, with your S70D, after charging to 100% while at a Supercharger?

Cheers

 

[Three60guy]

When I pick up my new S70D I will ask the chief head great technical super guru about which end of the battery is locked.

Cheers

 

[NOLA_Mike]

When I pick up my new S70D I will ask the chief head great technical super guru about which end of the battery is locked.

Cheers

Oh, and welcome BTW! You're gonna love the car regardless of what range the battery operates in.

Mike

 

[chillaban]

chillaban:

Do you recall what the voltage you observed, with your S70D, after charging to 100% while at a Supercharger?

Cheers

I will check the next time I have an opportunity to charge to 100%. I drove to Las Vegas this weekend and got to maybe a 90% charge at a Supercharger, the most I've ever done... Was going to go for 100% so that I could drive around town without making further charging stops, but at that point all the stalls have filled up and another P90D just arrived. I flagged him down to let him know I didn't need any more charge and gave him my spot.

 

[Three60guy]

Good going chillaban. I hope everyone is as considerate. Hopefully, you won't have to make a extra trip just to answer my question. Maybe others who already know that answer will stop on by. Have a good weekend.

Cheers

 

[davidc18]

I have a friend with a 2013 S85 and he charges to 100% everyday as the local SC. I asked him if he was worried about the battery and he said that as far as he is concerned, Tesla owns the battery for 8 years and if it gets damaged, it is Teslas problem. I charge mine to 90% each night at home, but I think he has a valid point. If/when it breaks, Tesla will replace/repair it. Food for thought.

 

[Three60guy]

gdavidc18:

That is certainly food for thought. However, I am one of those who hangs on to their cars for over 10 years. If I potentially abuse my car in the early years then it could come back to bite me in the later years when the normal warrenty has expired. So, that is the real reason I asked this question in the first place. I really want to know how badly i would be treating the battery pack given the circumstances that Tesla has intoduced for me. So, i guess the reason is still valid for me irregardless how long I keep it beyond the warrenty time period. I hope you understand.

 

[mhan00]

I have a friend with a 2013 S85 and he charges to 100% everyday as the local SC. I asked him if he was worried about the battery and he said that as far as he is concerned, Tesla owns the battery for 8 years and if it gets damaged, it is Teslas problem. I charge mine to 90% each night at home, but I think he has a valid point. If/when it breaks, Tesla will replace/repair it. Food for thought.

So your friend does all his charging at his local supercharger? Did he get an email from Tesla?

 

[davidc18]

Not to my knowledge.

 

[davidc18]

Same here which is why I charge to 90%.

 

[gavine]

Charging to 100% daily won't "break" the battery necessarily, but it will degrade it and lessen the range. The warranty covers degradation, but only to a point. He might degrade it to a point where he's not happy with the range, but it still might not be below warranty replacement range. Also, charging to 100% at a SuperCharger is very slow so your friend apparently doesn't value his time.