Best Practices for Charging?

babaloo

Member
First Name
Alan
Joined
Dec 14, 2020
Messages
9
Reaction score
1
Location
US
Vehicles
2021 Taycan, 2019 Cayenne. 2013 SL
Country flag
Just got my Taycan 2 days ago.

Was looking for a forum on best charging practices, eg,

1. Do you keep car on charger if you haven't driven recently ?

2. Do you charge if at 75%

3. What do you do if going on vacation for a month ?





Advertisement

 

daveo4EV

Well-Known Member
First Name
David
Joined
Jan 28, 2019
Messages
1,428
Reaction score
2,133
Location
Santa Cruz
Vehicles
Tesla(s), 911 GT3, Boxster S, Bolt, Taycan, Cayenn
Country flag
1. it doesn't matter - the car is not charging just because it's plugged in - it only charges according to schedule/profile - and only to the set battery percentage - once the car reaches it desired charge setting the charger is turned off at the car and no further charging takes place - it's like a light that is plugged into a socket, but turned off
2. 75% is fine - 85% is also fine - just don't constantly charge to 100%
3. leave it alone and unplugged - lower charger SOC of 40-65% is slightly better, but as long as it's not at 100% you're fine.
 

arijaycomet

Well-Known Member
First Name
Ari
Joined
Dec 24, 2020
Messages
104
Reaction score
65
Location
Cleveland, Ohio USA
Vehicles
2020 Porsche Taycan 4S
Country flag
1- There is no harm in leaving the car plugged in always, so long as you follow the response below (see #2). Older batteries did benefit from discharging and recharging, but I dont believe that is the case anymore. That said, ideally, don’t let the car sit at a low SOC (State of charge) for a prolonged period of time. In other words, if you’re at 20% or less, plugging in as soon as possible will benefit the battery life.

2- Porsche’s official suggestion is 85%. So again to compound this with above answer; you should just get in the habit of plugging the car in when parked if your parking situation permits (ex: garage with charger). Even if you are only at 60 ot 70 or 80 % SOC — just plug it in. And set it to 85% timer/profile limit — dont charge to 100% unless you really have to. (Side note: I charge to 90% regularly but at my office, and with an end time such that i rarely sit over 80% when parked overnight)

3- I’d suggest turning off all timers/profiles then setting a NEW profile charge limit to 50% (profile) (and leaving the car accordingly). That is a nice sweet spot for long term storage. Leaving the car plugged in and at 50% is a good resolve (and what, for example, Tesla did on the original Roadster and suggests on their modern cars, too)

Hope this helps!
 

HerrCooles

Active Member
First Name
Herr
Joined
Sep 15, 2020
Messages
32
Reaction score
38
Location
Vienna
Vehicles
Taycan, Panamera
Country flag
It is also specified in the sales contract:
Quote Porsche:
"If the vehicle is parked for longer than 2 weeks, it should be in a Ambient temperature between 0 ° C and 20 ° C and the battery charge level during the The service life can be kept between 20% and 50%."
 

Vim Schrotnock

Well-Known Member
First Name
Vim
Joined
Oct 20, 2018
Messages
664
Reaction score
738
Location
Cincinnati
Vehicles
GTB1 Race Cayman, Taycan Turbo S
Country flag
OK, I've heard that it is better to minimize the number of times you charge the battery. This is anecdotal - heard from a Porsche person that they let their car get to 40-50% before charging. Is this the case?

I'd rather just plug it in every night and charge to 85% regardless of the SOC. What are the opinions here, and anyone hear of or locate anything directly from Porsche?

This is actually a very important issue for all of us, and I don't think it's really been researched.
 

daveo4EV

Well-Known Member
First Name
David
Joined
Jan 28, 2019
Messages
1,428
Reaction score
2,133
Location
Santa Cruz
Vehicles
Tesla(s), 911 GT3, Boxster S, Bolt, Taycan, Cayenn
Country flag
charging cycles are tricky to nail down - because the rated charging cycles are from like 10% to 90% - if you‘re charging in a more narrow range there are more cycles - LiON battieres are rated in terms of charging cycles from a nearly empty state to a nearly full state - if you’re charging above nearly empty and not to full - then that’s is a fractional cycle not a full cycle…

it’s one of those things that with a 8 year 100,000 mile warranty I wouldn’t give it a lot of thought - unless you are charging more than once a day as a common practice I wouldn’t be that concerned.
 

feye

Well-Known Member
Joined
Sep 16, 2019
Messages
877
Reaction score
574
Location
Asia
Vehicles
Taycan 4S+
Country flag
I use my Taycan like an ICE, when I have not enough range for the next drive, I charge it to 100%.

I charge it with 11kW. I hardly ever do fast charging. Porsche left plenty of buffer, I expect to see very little range degradation, since I will have less than 30 charge cycles per year.

Yes, more battery testing data from Porsche would be great to have!
 

feye

Well-Known Member
Joined
Sep 16, 2019
Messages
877
Reaction score
574
Location
Asia
Vehicles
Taycan 4S+
Country flag
charging cycles are tricky to nail down - because the rated charging cycles are from like 10% to 90%...
Is that related to the the total 93.4 kWh capacity?
 

Vim Schrotnock

Well-Known Member
First Name
Vim
Joined
Oct 20, 2018
Messages
664
Reaction score
738
Location
Cincinnati
Vehicles
GTB1 Race Cayman, Taycan Turbo S
Country flag
charging cycles are tricky to nail down - because the rated charging cycles are from like 10% to 90% - if you‘re charging in a more narrow range there are more cycles - LiON battieres are rated in terms of charging cycles from a nearly empty state to a nearly full state - if you’re charging above nearly empty and not to full - then that’s is a fractional cycle not a full cycle…

it’s one of those things that with a 8 year 100,000 mile warranty I wouldn’t give it a lot of thought - unless you are charging more than once a day as a common practice I wouldn’t be that concerned.
That is very good to know, and good news. If the cycle rating is based on 'percentage charge', rather than number of charges, then I will plug in every night. I will always be at full power!:rock:
 

daveo4EV

Well-Known Member
First Name
David
Joined
Jan 28, 2019
Messages
1,428
Reaction score
2,133
Location
Santa Cruz
Vehicles
Tesla(s), 911 GT3, Boxster S, Bolt, Taycan, Cayenn
Country flag
I seem to recall that the number of "full charging" cycles for modern LiON batteries is measured in like 3000 cycles or some such - but again that _FULL_ cycle charges - even 3000 cycles is

daily charge cycle
3000 rated cycles / 365 days a year = 8.21 years of daily full charge cycles - but most days will _NOT_ count as a "full" charge cycle…so the math/models get very very tricky since we're not doing full discharge/charge cycles…not fully discharging the battery and not fully charging the battery greatly extends the LiON cell range - and then there is the "hold back" from the Porsche BMS - where we do not have access to the full range of the LiON capacity (93.4 kWh with 84 kWh usable) - this also extends the cycle count of the battery because of the hold back…

even lowering the charging cycles to 5 times a week has a dramatic effect

3000 rates cycles / (52 * 5) [260] = 11.53 years

and again I seem to remember that's like full cycle (5% to 95%) - if you're doing like 40% to 85% that's not considered a "full" cycle from a battery life longevity point of view - also if it's 40 amp @ 240 volts that's not "fast charging" which is also easier on the LiON cells…

based on experience with the Tesla Fleet (remember we now have 2008 roadsters and 2012 Model S vehicles on the road) - we're not seeing dramatic failures (or any failures) even though a 2012 Model S is approaching 9 years old…now.

Like I said unless you are routinely charging multiple times a day from a very low SOC % - I'm mostly unconcerned…but I have only a superficial understanding of this stuff.

https://batteryuniversity.com/learn/article/bu_1003a_battery_aging_in_an_electric_vehicle_ev
 

daveo4EV

Well-Known Member
First Name
David
Joined
Jan 28, 2019
Messages
1,428
Reaction score
2,133
Location
Santa Cruz
Vehicles
Tesla(s), 911 GT3, Boxster S, Bolt, Taycan, Cayenn
Country flag
it's important to note in the following scientific paper when the authors refer to "deep" cycle they are referring to the "raw" unmanaged cell capacity - all modern EV's that I'm aware have software/hardware between the user/vehicle and the "raw" cell - this software hardware provide a filter/buffer such that the end-user/vehicle is denied access to the full capacity range of individual LiON cells - i.e. well written software/hardware will prevent both full discharge and full charge capacities from ever "touching" the raw cells - keeping the overall vehicle battery pack in some sort of a "ideal" range where it is never truly fully discharged (even when at 0% shown on the dash) or fully charged (even when at 100% shown on the dash) - keeping the cells from exercising their true/raw full range is an industry standard trick/technique/best-practice that great extends the expected life of LiON cells and minimized the amount they degrade over the expected life of the battery pack…

EV batteries are expensive and valuable capital goods - and therefore are subject to highest quality battery engineering, manufacturing, and maintenance techniques. They differ materially in how they are managed vs. other "consumer grade" LiON battery (like notebooks, tables, cell phones, tools) - the smaller consumer grade batteries are neither capacity managed, nor temperature managed and are also much cheaper and easier to replace, and their overall capacity is simply not worth managing where replacement is measured in $50 or less retail costs…

unmanaged LiON batteries suffer from extreme and short life cycles measured typically in 3 years or less - EV batteries represent a substantially different approach and to date (other than Nissan) it seems these additional techniques greatly improve the expected/reasonable life of these important drive train elements.

again I'm not an expert in this area, and my knowledge is hobbyist level - but I am a keen observer and do have first hand experience with consumer grade (not automotive) technology LiON batteries and the management techniques (or lack of technique) available to the consumer electronics industry - quite frankly your Notebook can't have thermal management, and no one wants their laptop to stop charging at 100% and then drift down to 90% overnight before it's unplugged in the morning - basically everything done in a cell-phone/notebook computer is "wrong" for LiON longevity - we constantly keep them at 100%, they are charged at all sorts of temperatures, and the chargers never stop pushing electrons into the battery keeping the Lion battery topped off causing damage to cell…

this is not how it's done in any EV I'm aware of.

if Porsche is willing to warranty the battery pack for 8 years or 100,000 miles - I'm pretty sure they have high confidence the actual expected numbers are much higher and they really are not interested in having a lot of warranty claims. They are managing the battery pack to a point where I doubt the LiON cells are ever truly below 15% capacity or above 90% capacity at an individual cell level - keeping the cells/modules/over-all-pack in this sort of capacity range means it's entire operating life span is _NEVER_ experiencing a full charge/discharge cycle - which means the expected charge cycles is greatly extended because there are no full cycles in that pack overall life span - we also know Porsche (and others) employe aggressive thermal management (even at the expense of overall vehicle range) keeping the battery in it's sweet spot for temperature - again greatly decreasing LiON wear/tear…

there are four ways to quickly kill a LiON battery - do one or all four of these techniques at once to achieve a "speed kill" - i.e. kill the battery in record time - successful deployment of these 4 techniques should achieve a reduction of 80-90% original battery capacity in less than 1/3 of the expected calendar life span of the consumer grade battery - extra credit you may actually cause the battery to fail and have effectively zero capacity.
  1. charge it to full, and discharge it to empty when ever you can - often!
  2. rinse/lather/repeat #1 at virtually any and all temperatures - outside the cell's known good temps
    1. let the battery sit in the sun and get hot enough for the device to shut down to protect itself and the battery
  3. charge it as fast as possible all the time - never taper/adjust the charge rate based on environmental conditions or cell/module/pack conditions
  4. once it hits 100% keep trickle charging it to keep it 100% continuously - this is especially effective if you're doing it when the battery is too hot or too cold
  • well designed Vehicle BMS's (battery management systems) don't allow 1, 2, 3, or 4 to ever happen
  • nearly all consumer electronics allow 1, 2, 3, and 4 to occur as a matter of standard operating procedure
NOTE: Nissan allowed #2 to happen in early leafs and they suffered the consequences - Leaf in hot climates were know to lose 40-60% battery capacity in their first year (Arizona I'm looking at you) - Nissan still hasn't learned the this lesson as the latest leaf still only has a passive thermal system (air cooled with ambient outside air) and newer leafs still have a capacity loss problem. Tesla and Chevy Bolts (and others) with active/well-design thermal systems have dramatically better fleet behavior with few if any customers across a wide range of climates suffering major capacity loss.

The Taycan based on all accounts has a world class battery thermal management system. I'm going to remain unconcerned about actual battery health as I'm fairly confident there is sooooo much software between me and the actual cell capacities that only a massive failure in Porsche's BMS could actually allow me to cause damage to a LiON cell - in which case that's on Porsche and their warranty.

https://batteryuniversity.com/learn/article/bu_1003a_battery_aging_in_an_electric_vehicle_ev

Aging characteristics a Li-ion battery are complex and involve charge levels, charging speed, depth of discharge and temperature. Similar to a living organism, longevity is based on a combination of events that takes usage and environmental conditions into account.

SoC above 80% promotes capacity fade while a deep discharge increases the internal resistance. Li-ion must be shipped at 30% SoC; the recommended long-term storage is between 40–50%. Keeping Li-ion at high SoC affects battery life more than cycling in mid SoC range.

Future EVs may adjust battery charging to the user’s routine. Similar to an alarm clock, from Monday to Friday the EV is set in commute mode by only charging the battery to enable driving to work and back. The weekend follows the drive program as entered by an app on the EV owner’s smartphone.

The life of a Li-ion battery is prolonged when operating at a mild temperature. The EV battery should be warmed up to a comfortable temperature of around 25°C (77°F) for charging and driving. This is in contrast to storing or parking that should be at 10°C (50°F). Charging and operating Li-ion at low temperature causes stress, a phenomenon that does not apply equally to other chemistries.

The combination of low cycle-depth and low SoC leads to the longest battery life, but this does not fully utilize a large, heavy and expensive pack. To avoid resistance increase through deep a discharge, the onboard BMS always keeps some reserve capacity while indicating “empty” wrongly. Reserve capacity also protects the battery when charging at a high current because a completely discharged Li-ion cannot tolerate an ultrafast charge. For best results, charge more often without going full charge.
 
Last edited:

chrisk

Well-Known Member
Joined
Dec 3, 2020
Messages
294
Reaction score
249
Location
California
Vehicles
2020 Taycan 4S
Country flag
3. What do you do if going on vacation for a month ?
This is Porsche 's TSB describing what to do if you plan to park or store the car up to 3 months. It say to keep the car connected to the charger without timers but with a general profile at 85% and not use the Connect app too often.
https://static.nhtsa.gov/odi/tsbs/2020/MC-10182251-0001.pdf

It also advices to over inflate the tires to avoid flat spots because the car is heavy.
 
Last edited:

Tay Tay

Well-Known Member
Joined
Jun 9, 2020
Messages
206
Reaction score
150
Location
State of Confusion
Vehicles
Loving him is like driving a new Maserati down a dead-end street
Country flag

daveo4EV

Well-Known Member
First Name
David
Joined
Jan 28, 2019
Messages
1,428
Reaction score
2,133
Location
Santa Cruz
Vehicles
Tesla(s), 911 GT3, Boxster S, Bolt, Taycan, Cayenn
Country flag
double clicking on Porsche's warranty:

100,000 miles at 250 miles per charge = 400 charge cycles
8 years * 365 days a year = 2920 charge cycles

Porsche has most likely crunched the numbers and has chosen conservative estimates - these numbers mean they believe something like 95% or more of their battles can handle at least 3000 partial charge/discharge cycles, and at least 400 full charge/discharge cycles

based on this reverse engineering - I'm going humbling suggest Porsche expects their batteries in combination with their BMS to easily handle 1500 to 5000 charge cycles…and keep in mind we are also not talking about actual failure after these numbers are reached rather we are talking about the battery capacity being degraded by some percentage after this number of charge cycles…

I'm remain un convinced that I need to worry about the battery in most EV's if they are well designed and managed.

I would anticipate 250,000 to 300,000 miles easy on the Taycan battery - that will be 7-10 years from now - and then if it's really really bad - you can spend $40,000 and get a new fresh battery (probably more capacity and better chemistry) - and the rest of the vehicle is good to go - 40,000 for a 300,000 mile service to full rehabilitate the Taycan isn't that bad when you consider it's in line with cost of a full engine/transmission replacement for any equivalent porsche…
 

Advertisement





 
ZYRUS


Advertisement
Top