This seems so strange. Why would they sacrifice such a large, expensive battery over what should be an anticipated occurrence (leaving a car sit for a month or so). My lithium tool battery will cut off if the voltage gets low in order to protect itself. -Steve
> On Aug 15, 2025, at 11:39 AM, Kevin Horton via EV <[email protected]> wrote: > > In my experience, the actual daily battery drain on a modern Tesla, with > today's software, is much less than 1% a day. My wife's 2024 Model X was > parked for 5.5 days in June, with Sentry Mode OFF, and the battery SOC > dropped 1%. > > Kevin > >> On Aug 15, 2025, at 10:11, jamie via EV <[email protected]> wrote: >> >> >> Good to know. >> >> A de facto auto-bricking feature that kicks in after being parked for a few >> months doesn't seem like a major selling point. >> >> For that matter, having to accept a steady 1+%/day battery drain from the >> main pack doesn't seem particularly efficient. Is that typical of other >> brands as well? >> >> Nor does forced sacrificing of the accessory battery when the main pack gets >> too low. >> >> Couldn't some brilliant engineer do better? Perhaps design actual off >> switches to delay/avoid these conditions? >> >> >>> On 8/15/25 8:29 AM, Kevin Horton via EV wrote: >>> The current version of the Service Manual for my 2022 Tesla Model S has the >>> following in General Information -> Charging -> General: >>> Discharging the HV battery to 0% state of charge can permanently damage the >>> battery. To protect against a complete discharge, the vehicle enters a low >>> power consumption mode when the state of charge drops below 6%. In this >>> mode, the battery stops supporting the onboard electronics to slow the >>> discharge rate. >>> NOTE >>> When the low power consumption mode is active, the auxiliary 15V battery is >>> no longer being charged and can completely discharge within hours. If this >>> situation cannot be avoided, disconnect LV power (refer to procedure) from >>> the vehicle to preserve the 15V battery. If a complete discharge does occur >>> then the vehicle will need to be jump-started and the 15V battery must be >>> replaced. >>> ======= >>> The Owner's Manual has the following in the Sentry Mode section: >>> Sentry Mode requires your Battery to be at least 20% charged. If the >>> Battery falls below 20%, Sentry Mode turns off and the mobile app sends you >>> a notification. Power consumption may increase when Sentry Mode is active. >>> It has the following in the Battery Care section: >>> Even when Model S is not being driven, its Battery discharges very slowly >>> to power the onboard electronics. The Battery can discharge at a rate of >>> approximately 1% per day, though the discharge rate may vary depending on >>> environmental factors (such as cold weather), vehicle configuration, and >>> your selected settings on the touchscreen. Situations can arise in which >>> you must leave Model S unplugged for an extended period of time (for >>> example, at an airport when traveling). In these situations, keep the 1% in >>> mind to ensure that you leave the Battery with a sufficient charge level. >>> For example, over a two week period (14 days), the Battery may discharge by >>> approximately 14%. >>> Kevin >>>> On Aug 15, 2025, at 8:21 AM, Collin Kidder via EV <[email protected]> >>>> wrote: >>>> >>>> Well, they do some of that. Sentry mode will disable at some point, I think >>>> 30% SOC. The car won't enable those sort of "bonus" features at low SOC but >>>> it seems that otherwise it's perfectly fine with trying to kill the HV >>>> battery to save your $200 12V battery and still be able to run the >>>> computers. That does seem to be a rather poor choice. Personally, I'd >>>> rather ruin the 12v battery and leave the main HV battery at 20% or >>>> something. I believe most other current EVs (Bolt, Mach-E, etc) do disable >>>> pretty much everything to do with the HV battery at a certain SOC so that >>>> it stays good even if that means your 12V battery has to die. >>>> >>>> On Thu, Aug 14, 2025 at 9:37 PM Bryce Nesbitt via EV <[email protected]> >>>> wrote: >>>> >>>>> And YES this is a serious design flaw. >>>>> >>>>> The car could implement several battery actions: turn off sentry, camping, >>>>> and eventually LTE data. Have a "battery saver" mode that wakes up >>>>> once a week to call >>>>> Tesla over mobile data, but that's it. >>>>> _______________________________________________ >>>>> Address messages to [email protected] >>>>> No other addresses in TO and CC fields >>>>> HELP: http://www.evdl.org/help/ >>>>> >>>>> >>>> -------------- next part -------------- >>>> An HTML attachment was scrubbed... >>>> URL: >>>> <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20250815/43a9d4ec/attachment.htm> >>>> _______________________________________________ >>>> Address messages to [email protected] >>>> No other addresses in TO and CC fields >>>> HELP: http://www.evdl.org/help/ >>>> >>> _______________________________________________ >>> Address messages to [email protected] >>> No other addresses in TO and CC fields >>> HELP: http://www.evdl.org/help/ >> >> _______________________________________________ >> Address messages to [email protected] >> No other addresses in TO and CC fields >> HELP: http://www.evdl.org/help/ >> > > _______________________________________________ > Address messages to [email protected] > No other addresses in TO and CC fields > HELP: http://www.evdl.org/help/ > _______________________________________________ Address messages to [email protected] No other addresses in TO and CC fields HELP: http://www.evdl.org/help/
