Is Scheduled Charging Reliable?

[Frankman60]

For anyone that regularly uses the scheduled charging feature in their MS, does it work reliably? I have time-of-use electricity and the rates vary significantly based on the the time period (from 17 to 44 cents per kWh). The Super Off Peak period is 12 AM to 5 AM, when I will be charging my MS on a NEMA 14-50 50 amp circuit. If I plug in the MS and have it scheduled to begin charging at 12:00 AM, does it reliably begin at that time (e.g. Not before that time or after that time)?

 

[st50maint]

Yes, in my experience it is very reliable.

 

[AB4EJ]

It has worked flawlessly for me. I turn it on and off all the time; if I have a lot of solar power coming in and no other loads, I will charge during peak sun; otherwise, at a fixed time at night for lower night rates.

 

[Boourns]

It has never failed me either.

 

[paulkva]

+1, I've never had problems with scheduled charging. I set mine to start at 1:05am because "super-off-peak" rates start at 1:00am.

I do occasionally forget to plug it in at night, which is of course a completely separate issue, but I'm using VisibleTesla on my home computer to remind me.

 

[Frankman60]

Thanks to all. I am glad to hear that this feature works reliably.

 

[animorph]

There is one "problem" case that has cropped up here a couple of times.

If the car decides it needs to charge and it is within a window of time 6 hours or less from the start of your set charging start time, it will start charging. This can happen if the car's SOC falls to a trigger level (something like -5% down from your set charge level) at 4 AM (4 hours after your set 12 AM start time) and decides it needs to top off the battery. I assume this would also happen if you arrived home at 5 AM and plugged the car in, but I don't have a Tesla yet so you'll have to tell me.

 

[johnnyS]

never had a problem with timed charging since the software was released.

 

[WannabeOwner]

Tangential issue:

Software update has interrupted charging for me ... I now change the scheduled update time to be an hour or two prior to my off-peak start time, rather than the original default of early hours of the morning.

For me off-peak is midnight-7am in Winter and 1am-8am in Summer. I need to remember to change the scheduled time on the Dash when the clocks change ... and I have one hour's less charging time overnight in Summer if I leave early (normally leave at 6am for work), so if I need a full charge I have to remember to override the scheduled start time ... that's only a problem for me if I am charging from less than 40 miles as a normal 90% charge from more than 40 miles residual range will finish before 6am.

I'd like an option for a "Finish charging by" time, or even a "Start THIS charge at" time.

 

[Rocky_H]

I’ll clarify one piece that @animorph said. He mentioned “within a window of time 6 hours or less from the start of your set charging start time”, but that 6 hour time window is only AFTER the set charging time. This is described in the car’s manual. It’s to take care of the situation where let’s say you have it scheduled to start at midnight, but you have a late night and get home at 1:25AM and plug in. It is being helpful in that it’s shortly after your scheduled time, so you won’t miss that night’s charge.

 

[Frankman60]

There is one "problem" case that has cropped up here a couple of times.

If the car decides it needs to charge and it is within a window of time 6 hours or less from the start of your set charging start time, it will start charging. This can happen if the car's SOC falls to a trigger level (something like -5% down from your set charge level) at 4 AM (4 hours after your set 12 AM start time) and decides it needs to top off the battery. I assume this would also happen if you arrived home at 5 AM and plugged the car in, but I don't have a Tesla yet so you'll have to tell me.

My wife's C-Max Energi does this too. Even though it is a plug-in hybrid, when it thinks that the battery is too low it will begin charging immediately when plugged in even though it set up to charge during the Super Off Peak rate period. It charges the battery a little and then charges the remainder after 12:00 AM.

 

[Boatguy]

It's worked reliably for me, but there is a case where the car draws power outside the time window. My car is set to begin charging at 1:30am. But if the car is plugged in, and I'm sitting in the car at say 4:00pm, the systems start up (HVAC, center display, etc.) as they do just when sitting (car still OFF), it will begin drawing 4-5a from the HPWC. The car continues to draw power for about a minute after I get out of the car and lock the doors. It's not really charging, but it's definitely drawing current.

 

[ArtInCT]

Works perfectly... If you remember to plug in.

 

[Frankman60]

I’ll clarify one piece that @animorph said. He mentioned “within a window of time 6 hours or less from the start of your set charging start time”, but that 6 hour time window is only AFTER the set charging time. This is described in the car’s manual. It’s to take care of the situation where let’s say you have it scheduled to start at midnight, but you have a late night and get home at 1:25AM and plug in. It is being helpful in that it’s shortly after your scheduled time, so you won’t miss that night’s charge.

OK, that makes sense and I like that feature even though the MS will continue to charge into the next rate period if the MS is plugged in very late (e.g. 3 AM). In my case, the difference between Super Off Peak and Off Peak is only 4 cents per kWh so that is fine. I just want to be sure I stay away from Peak unless I really need it because it is 44 cents per kWh.

 

[BertL]

My lowest TOU rate is from 12-5AM year-round every day. I purposely have dual-chargers and an 80A HPWC, and have never had a problem with regularly scheduled charging not completing on my S90D within that timeframe. (I specifically purchased the dual charger and put in that circuit so I could effectively do a full "fill-up" at lowest rates if I ever wanted to.) As @animorph and @WannabeOwner suggest, there are a couple of things that CAN be exceptions.

• The scenario @animorph suggests has bitten me a couple of times when my MS has been plugged-in and not driven for a couple days -- it's started it's "top off" off of my planned 12AM schedule and outside my 5-hour TOU rate window.
  • As I've said in other threads, I can understand Tesla's logic why perhaps this exception was originally created back-in-the-day when 40kWh batteries were the norm, but with 85 and 90 now being effectively the standard and perhaps representing a majority of the fleet, Tesla's logic no longer holds together for me. IMHO, unless battery level is so extremely low it's going to possibly damage the pack, I believe Tesla's firmware should just wait to begin any needed top-off until the next scheduled charging time, so those of use that do have TOU rates or maybe are trying to use their own solar, can ensure we always use the lowest rates being applied when top-off is necessary. On my S90D, there is little benefit gaining 7-8 miles in an auto-top-off when I already have more than 240 miles of Rated Range available. While it's pennies difference having that little top-off happen outside my low TOU rate upon occasion, it's one of the little refinements I expect Tesla should keep up with and manage on my behalf. Tesla could get really fancy and have different logic based on the size of the battery I suppose, or offer owners an option, but I suspect you get my POV.
  • Of note: With my scheduled charging start time of 12AM, the couple of times I have arrived home between 12:01AM and 6AM, plug-in, and my MS needs a charge or top-off, my MS has NEVER started charging until the next night.
• I don't consider scheduled software updates to be any sort of issue for me, as it's my decision as to when I ask my MS to apply those updates on the rare occasion they arrive, so if they interrupt my charge, that's on me.

As to folks suggesting a "Finish charging by" time which is introduced every now and then in various threads, I agree it may be nice for some -- especially in colder climates, but personally I suspect we'll just have another set of owners that will then complain it does not always work within a reasonable tolerance level. The issue is IMHO, when charging to say my normal 90%, estimating finish time is not rocket science and can generally be accurate within a reasonable margin of error -- so backing-up when to start that charging would be fairly easy. OTOH, at least with my early S90D, I can NEVER estimate the time it takes to trip charge to 100%. The last few percentage points when battery balancing is taking place has taken a handful of minutes to more than 30 minutes, and I have never been able to predict it ...introducing a huge variable that I suspect would make estimating when to start a trip charge difficult for Tesla to calculate... Sure, Tesla could pad that by maybe 30 minutes to hopefully always be done by the time an owner wants, but then we'll have people say their MS is ending it's charge too early or it's not accurate enough. Ah, consumers. We'll never all be happy.

 

[Frankman60]

Tangential issue:

Software update has interrupted charging for me ... I now change the scheduled update time to be an hour or two prior to my off-peak start time, rather than the original default of early hours of the morning.

For me off-peak is midnight-7am in Winter and 1am-8am in Summer. I need to remember to change the scheduled time on the Dash when the clocks change ... and I have one hour's less charging time overnight in Summer if I leave early (normally leave at 6am for work), so if I need a full charge I have to remember to override the scheduled start time ... that's only a problem for me if I am charging from less than 40 miles as a normal 90% charge from more than 40 miles residual range will finish before 6am.

I'd like an option for a "Finish charging by" time, or even a "Start THIS charge at" time.

The software update thing is new to me and I did not consider that. I have been driving a Volt for 5 years and it doesn't update its software like the MS! If I understand this correctly, I can schedule when I want the software update to begin, if it has already been downloaded? I understand that the update will download when my MS is connected to my home's WiFi but what I don't understand is do I globally set a time to do updates or do I schedule the update time each time there is an update? You mentioned that you schedule the update an hour or two before the start of the charge. Is 2 hours always enough time for the update to complete and does the charge ever not happen after an update (e.g. Update clears scheduled charge start time)? Thanks.

 

[BertL]

The software update thing is new to me and I did not consider that. I have been driving a Volt for 5 years and it doesn't update its software like the MS! If I understand this correctly, I can schedule when I want the software update to begin, if it has already been downloaded? I understand that the update will download when my MS is connected to my home's WiFi but what I don't understand is do I globally set a time to do updates or do I schedule the update time each time there is an update? You mentioned that you schedule the update an hour or two before the start of the charge. Is 2 hours always enough time for the update to complete and does the charge ever not happen after an update (e.g. Update clears scheduled charge start time)? Thanks.

You receive a notice on your CID an update is available. You can then elect to install it then or at a future scheduled time. There is no global setting. In my 10 months of ownership, the biggest updates have quoted 1hr-45min as the estimate, but all have completed in far less than that. Minimal dot-releases can take 15-20 mins. Don't think there are a lot of updates that come in OTA or via WiFi -- there have not been. You may see references to a lot because there are a bunch of the little dot releases in the wild around they world -- but they are not commonly PUSHed to every vehicle in the fleet. It's not a biggie -- but again, you are in control, so it's your decision to perhaps spend a few more pennies to get the update applied now rather than when your lower rates kick in.

 

[Frankman60]

My lowest TOU rate is from 12-5AM year-round every day. I purposely have dual-chargers and an 80A HPWC, and have never had a problem with regularly scheduled charging not completing on my S90D within that timeframe. (I specifically purchased the dual charger and put in that circuit so I could effectively do a full "fill-up" at lowest rates if I ever wanted to.) As @animorph and @WannabeOwner suggest, there are a couple of things that CAN be exceptions.

• The scenario @animorph suggests has bitten me a couple of times when my MS has been plugged-in and not driven for a couple days -- it's started it's "top off" off of my planned 12AM schedule and outside my 5-hour TOU rate window.
  • As I've said in other threads, I can understand Tesla's logic why perhaps this exception was originally created back-in-the-day when 40kWh batteries were the norm, but with 85 and 90 now being effectively the standard and perhaps representing a majority of the fleet, Tesla's logic no longer holds together for me. IMHO, unless battery level is so extremely low it's going to possibly damage the pack, I believe Tesla's firmware should just wait to begin any needed top-off until the next scheduled charging time, so those of use that do have TOU rates or maybe are trying to use their own solar, can ensure we always use the lowest rates being applied when top-off is necessary. On my S90D, there is little benefit gaining 7-8 miles in an auto-top-off when I already have more than 240 miles of Rated Range available. While it's pennies difference having that little top-off happen outside my low TOU rate upon occasion, it's one of the little refinements I expect Tesla should keep up with and manage on my behalf. Tesla could get really fancy and have different logic based on the size of the battery I suppose, or offer owners an option, but I suspect you get my POV.
  • Of note: With my scheduled charging start time of 12AM, the couple of times I have arrived home between 12:01AM and 6AM, plug-in, and my MS needs a charge or top-off, my MS has NEVER started charging until the next night.
• I don't consider scheduled software updates to be any sort of issue for me, as it's my decision as to when I ask my MS to apply those updates on the rare occasion they arrive, so if they interrupt my charge, that's on me.

As to folks suggesting a "Finish charging by" time which is introduced every now and then in various threads, I agree it may be nice for some -- especially in colder climates, but personally I suspect we'll just have another set of owners that will then complain it does not always work within a reasonable tolerance level. The issue is IMHO, when charging to say my normal 90%, estimating finish time is not rocket science and can generally be accurate within a reasonable margin of error -- so backing-up when to start that charging would be fairly easy. OTOH, at least with my early S90D, I can NEVER estimate the time it takes to trip charge to 100%. The last few percentage points when battery balancing is taking place has taken a handful of minutes to more than 30 minutes, and I have never been able to predict it ...introducing a huge variable that I suspect would make estimating when to start a trip charge difficult for Tesla to calculate... Sure, Tesla could pad that by maybe 30 minutes to hopefully always be done by the time an owner wants, but then we'll have people say their MS is ending it's charge too early or it's not accurate enough. Ah, consumers. We'll never all be happy.

Bertl, you mentioned a few things that concern me. BTW, we are probably on the same SDGE rate plan.

You said that your MS never begins charging if you plug it in after 12 AM, and it waits until the next day to begin charging instead. Because that is not supposed to happen, have other people also experienced this? It should begin charging immediately when plugged in within a 6 hour window.

The other thing was the "top off" charging outside of the scheduled charge window. I don't understand why the MS would do that unless the battery level was critically low. But the situation you described is that the MS is doing a "top off" of the battery before the scheduled charge time. Does it begin charging immediately when when plugged in? This could be a problem if I plug in my MS between Noon an 6 PM when the electricity rates are the highest.

 

[Lloyd]

Never Failed to actuate properly

 

[Frankman60]

You receive a notice on your CID an update is available. You can then elect to install it then or at a future scheduled time. There is no global setting. In my 10 months of ownership, the biggest updates have quoted 1hr-45min as the estimate, but all have completed in far less than that. Minimal dot-releases can take 15-20 mins. Don't think there are a lot of updates that come in OTA or via WiFi -- there have not been. You may see references to a lot because there are a bunch of the little dot releases in the wild around they world -- but they are not commonly PUSHed to every vehicle in the fleet. It's not a biggie -- but again, you are in control, so it's your decision to perhaps spend a few more pennies to get the update applied now rather than when your lower rates kick in.

Thanks for the info. Does the MS need to be plugged in when doing a software update?