© Copyright 2022-2024 by Mark Derrick
This detailed article (estimated reading time 20 minutes) is authored by Mark, with help from his sister Lisa who manages charging logistics during their longer road trips with the North American model Porsche Taycan 4S. You can find plenty of articles and reviews about charging using data based on theoretical calculations that assume ideal circumstances for charging power and time. In the real world, the values discussed here are more likely to mirror your own experience. If you have any suggestions or corrections for this article, please email them to [email protected]
The 800 volt architecture of the Porsche Taycan 4S has a Performance Battery Plus option with a gross storage capacity of 93.4 kWh. However, as with most other modern battery electric vehicles (BEV or more broadly EV) the accessible capacity is intentionally limited. The Taycan battery management system does not allow the battery to be discharged until completely empty or charged until completely full – which could result in permanent damage. Porsche reserves about 10% of the gross storage capacity for this purpose, leaving 83.7 kWh of accessible battery capacity and an EPA driving range of 235 miles.
The nature of all EV lithium chemistry means as the battery accumulates an ever-increasing number of charge and discharge cycles, the maximum energy storage capacity of the battery is gradually reduced and thus the maximum driving range is also permanently reduced. However, do not assume you should minimize the number of charging cycles by only charging when the battery is deeply discharged and always charging until the battery is full. While in theory the battery State of Charge can be run from 100% down to 0% of its capacity, studies have shown that consistently operating a EV with a battery SoC significantly below 20% or significantly above 80% will also more rapidly reduce the EV maximum driving range. The "80/20 Rule" suggests a charging session will be needed about every 150 miles of Taycan local daily driving.
Another accepted wisdom in the battery industry is the faster the charging, the faster the battery storage maximum capacity will permanently degrade. The Taycan is capable of charging at speeds up to 270 kW for short periods, but also has a "Battery-friendly Quick Charging" setting when enabled by the driver will limit the charging speed to about 200 kW. For local daily driving, this suggests avoiding hyper-fast charging when practical. Don’t worry; while fast charging may have some influence on EV battery life, recent data has demonstrated the long-term effect is minimal even when it is the primary charging method. For conscientious owners, expect your Taycan maximum range to unavoidably decline about 2% per year and that ten years is a reasonable expectation of the Taycan battery service life.
There are three common types of EV charging equipment in the US -- AC Level 1 (single phase 120 VAC) which can take days for a full charge, AC Level 2 (dual phase 240 VAC) which can take hours for a full charge, and DC Fast Charging (400 VDC or 800 VDC) which takes a few minutes. (DC Fast Charging is sometimes incorrectly called Level 3, notably in some Porsche marketing content, but Level 3 is actually a deprecated three phase AC charging standard - there is no DC equivalent.) EV owners typically charge at home using AC Level 2. For longer trips outside their local area, EV drivers normally rely upon branded EV charging networks of public DC Fast Charging (DCFC) stations including the Electrify America (EA) network preferred by Porsche.
There are three vehicle charging connectors of interest to Taycan drivers in the US. The connector most widely used on non-Tesla vehicles in North America is the Combined Charging System Combo 1 (aka CCS1), which is used for DC Fast Charging and is also compatible with the SAE J1772 connector used for AC Level 2 charging at home and destinations. Telsa vehicles have the NACS connector that supports both AC Level 2 and DC Fast Charging.
The Taycan can accept a battery charge via a J1772 socket located on the driver side of the vehicle or a CCS1 socket located on the passenger side, thus the Taycan may be AC charged from either side of the vehicle while it may be DC charged only from the passenger side. The two charging ports are located one on each side just forward of the doors, but the Taycan cannot simultaneously charge from both sockets. The Taycan on-board charging system can accept power from the connectors at theoretical maximum charging speeds up to:
The 19.2 kW on-board charging optional upgrade (KB4) enables the Taycan to accept a maximum charging speed of 22 kW (although 19.2 kW is the maximum allowed by the J1772 connector), otherwise the Taycan is limited to 11 kW. Taking advantage of the increased AC charging speed requires a very high amperage dedicated branch circuit that many residential electrical systems cannot support without expensive upgrades.
The 150 kW on-board charging optional upgrade (KM2) enables the Taycan to accept a maximum charging speed of 150 kW, otherwise the Taycan is limited to 50 kW. In the US, only the Telsa DC Fast Charging network is configured for 400 volts exceeding 50 kW (see discussion of Tesla charging compatibility with the Taycan later in this article.)
Porsche has issued several Taycan firmware updates across the model years that altered the battery management system and charging behavior. The major MY 2023 workshop firmware update (actually made available in fall of 2022) has modified the front wheel drive motor behavior to gain some additional efficiency in Normal mode. In July 2023, Porsche issued a minor over-the-air firmware update in the US for the battery management system to improve charging speed near the end of the charge cycle and to maintain short charging times as the battery ages. These updates might explain some minor differences in Taycan charging recommendations as well as conflicting observations by drivers and reviewers.
Porsche's use of the term 'Charger' is a misnomer; these devices are more properly termed Electric Vehicle Supply Equipment (EVSE). The EVSE provides an interface to the electrical mains supply, then controls and monitors the amount of power delivered to the on-board charging system of the car. The charger in the EV then controls and monitors the amount of power delivered to the storage battery. The EVSE and the EV on-board charger cooperate to determine how much power the EVSE can deliver and how much power the EV can accept, then agree on a speed of charging.
The Porsche Mobile Charger Plus accessory comes standard with Taycan. The Porsche Mobile Charger Connect option (NW2) has similar charging capacity to the Plus, and is Wi-Fi enabled with a touch screen control and information display similar to the one inside the Taycan. Either are capable of charging speeds up to 9.6 kW from a plug-in outlet. If a 240 VAC outlet is not available, the equipment can be reconfigured for a 120 VAC outlet although Porsche recommends using AC Level 1 charging only in emergencies. The fastest AC Level 2 charging requires permanently installed equipment that is directly wired (no plug and socket, aka 'hardwired') to the circuit breaker panel. The hardwired Porsche Wall Charger Connect is capable of the 19.2 kW maximium AC Level 2 charging speed.
In practice, the sustained charging speed for all AC Level 2 devices will often be less than their specification. The amount of current the EVSE is allowed to draw from the electrical supply circuit must be limited in order to prevent overheating or tripping the circuit breaker at the panel. They have a setting that must be configured to limit the draw to 80% or less of the actual amperage rating of the electrical supply circuit breaker. In cases where a new circuit must be added to the panel, the amperage rating of the new circuit may also be limited by the existing loads on the mains supply.
Porsche also recommends selecting a current draw of no less than 8A to protect the auxiliary 12 VDC battery. The auxiliary battery is used to power standard vehicle functions as well as the driver instrument cluster and controls. The failure of the auxiliary battery will deactivate the entire Taycan electrical system and prevent the car from operating. This necessitates a service technician having to manually recharge the auxiliary battery using a specialized external lithium-ion battery charger or in rare cases replace the auxiliary battery itself.
Among Taycan owners the Porsche branded EVSEs are not well regarded but there are plenty of alternative EVSE choices. At home I originally used the Porsche Mobile Charger Connect, which with a 40A current draw setting from a 50A outlet never delivered anything close to its 9.6 kW rating, typically 7.2 kW was the most ever seen. I now use a Enel X Way Juicebox 48 hardwired to a 60A circuit and theoretically capable of 11.5 kW, but which is consistently delivering 10.2 kW as reported by the Taycan.
A prudent practice would be to consider ordinary household outlets the last choice for plugging in any mobile EVSE due to the risk of overloading the circuit. Many residential garages are pre-wired with two dedicated circuits for an electric clothes washer and dryer appliance set, and with their higher amperage ratings these are better choices. The 20A @ 120 VAC washer outlet will directly accept the Level 1 NEMA 5-15P plug included with the Porsche mobile EVSE and can take several days to fully trickle-charge a deeply discharged battery.
An AC Level 2 EVSE plugged to a 30A @ 240 VAC dryer outlet and set to draw a maximum of 24A is limited to delivering about 5 kW to 6 kW. It takes about 11 to 13 hours to charge the battery from 20% to 80% and an hour of charging will typically add roughly 15 miles of range to your Taycan. The wall outlet for the dryer is a three-prong NEMA 10-30R (houses built 1996 or earlier) or four-prong NEMA 14-30R (houses built 1997 or later) socket. Using the 30A dryer outlet requires an inexpensive and widely available RV adapter for the 50A plug that comes with the Porsche mobile EVSE. If the outlet has an appliance plugged in and you don’t want to bother with having to repeatedly unplug and plug to charge, then SplitVolt has a device that allows both to remain plugged in at the same time.
For faster charging with a plug-in EVSE, many EV owners install a dedicated 50A non-GFCI circuit with an industrial grade heavy-duty NEMA 14-50R outlet (Porsche recommends the Hubbell HBL9450A) located near where they plan to park the vehicle when being charged. An AC Level 2 EVSE drawing 40A from a 50A outlet will deliver about 7 kW to 8 kW and typically takes about 8 to 9 hours to charge the battery from 20% to 80%. An hour of charging will add roughly 20 miles of range to your Taycan 4s. This is about the extent of what can be achieved with a plug-in EVSE.
A J.D. Power study concluded that owners who installed a permanently hardwired AC Level 2 EVSE also had the highest level of satisfaction with home charging. Drawing 48A from a 60A circuit can deliver about 9 kW to 10 kW and typically takes about 6 to 7 hours to charge the battery from 20% to 80%. An hour of charging will add about 30 miles of range to your Taycan 4s. There is 240 VAC equipment capable of charging speeds up to 19.2 kW that can replenish a fully depleted Taycan battery in as little as 5 hours, but most residential electrical systems cannot support the 100A branch circuit required for such speeds.
In my experience, most non-Telsa AC Level 2 public destination EVSEs typically deliver 5 kW to 7 kW, even though they are almost always hardwired. The fastest possible EV public charging is available from a DC Fast Charge EVSE that can deliver power rapidly but requires commercial grade 3-phase electrical service. Older DC Fast Charging EVSEs will deliver up to 50 kW. Newer DC Fast Charging EVSEs can deliver significantly more power, up to 150 kW or in some cases up to 350 kW.
EV batteries cannot maintain a constant maximum fast speed of DC power acceptance through a full charge cycle. The Taycan charging speed will vary substantially during the charge depending on the battery SoC as well as how close the battery is to ideal temperature. The Taycan will DC charge faster initially if the battery SoC is low, with power acceptance initially well over 200 kW if battery-friendly quick charging is not enabled. DC charging is significantly slower when the SoC is greater than 80% with power acceptance typically dropping to well under 100 kW.
In some cases, two or more adjacent EVSEs may be configured to cooperate and share a single electrical supply. Power sharing allows multiple EVSEs to distribute the available energy capacity proportionally across all active EVSEs. Another term for this arrangement is 'balanced', and it works in practice because power demand from multiple vehicles during charging varies greatly through the charging cycle and is unlikely that all will have peak demand at the same time. Few public charging stations identify which if any of their EVSEs are balanced, but that can explain why at a busy station your Taycan is not charging at the speed you expect.
As a practical matter, it is rare you will be DC fast charging starting with SoC of under 10% or continuing to DC charge above 80%. Using DCFC to replenish a Taycan battery at nominal temperature and an SoC from 10% to 80% with a 350 kW EVSE typically takes around 25 to 30 minutes if battery-friendly quick charging is enabled. A 150 kW EVSE takes about 3 to 5 minutes more. Continuing to DC charge from 80% to 100% has the potential to substantially extend the charging session total time; charging from 10% to 95% can take 45 to 50 minutes. These times are based on our experience using mostly the EA 150 kW and 350 kW public charging network and your results will differ, but are unlikely to be the published ideals that also do not consider the time it takes to establish and terminate the session.
Some DCFC stations may offer a mixture of equipment with different charging speeds. At those stations, when a 150 kW EVSE is immediately available there is rarely benefit to waiting for a 350 kW EVSE to become available. Only if the battery SoC is less than about 30% and battery-friendly charging is disabled, will the Taycan charge significantly faster than 200 kW and then only very briefly under ideal conditions. As the SoC increases the charging speed declines, with the result that much if not most of the charging session time on a 350 kW EVSE is no better than when using a 150 kW EVSE. Many Taycan drivers report that the typical EA 150 kW EVSE will actually charge initially as high as 175 kW, and this is also our experience.
There are many public destinations such as workplaces, hotels, restaurants and parking garages that offer AC Level 2 charging as a free or low-cost amenity. The DC Fast Charging stations are usually located near major commercial facilities with a lot of highway traffic such as shopping malls and big box stores as well as truck stops and travel stores.
The "Porsche Charging Service" free subscription allows the driver to use the Taycan PCM to locate and navigate to many nearby public charging stations. The latest version of the "My Porsche" smartphone app can also locate and navigate to preferred charging stations as well as manage and pay for charging at EA stations. All the major EVSE networks have branded smartphone apps that are best at finding their own network charging stations as well as reporting their real-time status and availability. Drivers should also install a charging station brand-agnostic mobile app; they are essential for finding and navigating to virtually every available public charging station including many non-networked stations. One of the most popular is PlugShare, offering a rich amount of crowd sourced information about the stations and nearby amenities.
The price at public charging stations can vary widely, depending on the network region and type of EVSE as well as whether you are paying the "guest" price or "member" subscription price, in some cases even time of day. Because some states have restrictions on anyone other than public utilities billing by the kWh for electricity, the price may be expressed as "EV parking" by the hour instead of a price per kWh delivered. ChargePoint is a large network of privately owned charging stations, and the individual owners set whatever price they wish. It is worthwhile to check prices if you have a choice of among charging stations and EVSEs.
Tesla has a public network of AC Level 2 destination stations at popular hotels, restaurants and resorts. Telsa also has a highly regarded public network of DC Fast Charging 'Supercharger' stations. All North American Telsa vehicles since 2012 use the same unique Tesla developed NACS connector. Originally proprietary to Tesla and now standardized as the SAE J3400 connector, it can NOT be used to directly charge the Taycan. However, any Tesla or other brand NACS compatible AC Level 2 EVSE can charge the Taycan using a third-party NACS to J1772 plug adapter such as the products made by TeslaTap.
In 2022, Tesla announced a DC Fast Charging compatible NACS to CCS1 adapter they named 'Magic Dock' that will be built in to their Supercharger equipment. The Taycan requires the KM2 option to use Tesla Superchargers at greater than 50 kW. Currently, very few Tesla Supercharging stations in the US have been upgraded with the Magic Dock feature and the number of Telsa CCS locations is extremely limited.
Also in 2022, Tesla opened their NACS connector for use by other EV manufacturers. Most manufacturers of EVs have now announced they will offer NACS compatible DC Fast Charging, either as a Supercharger compatible adapter for their current models or as an integrated option for their future model years. In December 2023, Porsche announced NACS compatible solutions for DC Fast Charging, expected to become available in 2025.
There are reports of some unique annoyances associated with using a Tesla EVSE for charging the Taycan. Parking layouts and the length of the cables on Tesla branded public EVSEs are often very optimized for Tesla vehicles, which have the charging port located on the driver-side rear corner. This creates a challenge to park so the relatively short cable from the Telsa branded EVSE will reach the Taycan charging port. Sometimes the Taycan parking orientation required for the cable to reach will also prevent another vehicle from using an adjacent charging stall. The Telsa Superchargers are 400 volts and thus the few Tesla Supercharging stations with the Magic Dock adapter cannot achieve the 800 volt charging speeds of which the Taycan is capable.
Select a working EVSE with a compatible connector; a J.D. Power study in 2022 concluded as many as 1 in 5 charging attempts fail because the EVSE is out of service or incompatible. Courteous EV drivers may leave the charging cable laying on top or beside an out-of-service EVSE rather than returning it to the connector cradle, signaling other drivers to avoid the EVSE. Park so that you are close enough for the power cable from the EVSE to reach the charging socket on the vehicle, then plug-in.
Authenticate the EV charging session for those that require billing, typically using a mobile app or swiping/tapping a payment card. When successfully authenticated, the charging session will begin. Once the charging session automatically completes or is manually ended, after a brief grace period most DCFC stations will begin billing for 'idle' time if the cable remains connected so always move the vehicle out of the charging stall asap after charging.
Charging at a public EVSE works slightly differently with each of the smartphone apps and with each of the charging station networks, plus the exact sequence of steps are not always intuitive. Figuring out the differences when under time pressure as they are encountered can make for frustrating early experiences with public charging. "Plug & Charge" is a seamless process that allows a vehicle to automatically initiate a charge once it is simply plugged into a Plug & Charge enabled EVSE.
Currently, Porsche supports Plug & Charge only at EA stations. Porsche Charging Service subscription must previously have been activated and a credit card stored at the My Porsche website. Plug & Charge must also be enabled in PCM settings on the Taycan. If everything is configured, then just drive up and plug in without further authentication. It can take up to 60 seconds to establish the charging session automatically; be patient and do not interrupt the process.
A new Porsche Taycan includes three years of free DCFC charging sessions (first 30-minutes of the session is free) at any of the EA stations. If you wish to take advantage of Porsche free charging, then you must establish the session using either the My Porsche app or Plug & Charge. The free charging session will not automatically end after 30 minutes, it must be manually terminated or else charging that exceeds 30 minutes plus any idle time will be billed to your Porsche Charging Service account.
The Taycan has a heat pump that the battery management system (BMS) can use to adjust the temperature of the high-voltage battery as it deems appropriate. Battery temperature cannot be directly controlled by the driver, nor are there any instrumentation symbols to specifically indicate the BMS is active although this might be inferred by tracking the displayed battery temperature. On longer trips, the Taycan driver might improve charging efficiency by navigating to DCFC stations using the PCM Charging Planner. This allows the Taycan to adjust the battery temperature in anticipation of the upcoming charging session (what Porsche confusingly terms "preconditioning" the battery.)
For the battery management system to optimize the battery temperature for charging, the PCM navigation system destination MUST be set by selecting a specific charging station using the PCM Charging Planner and not simply entering the street address of a charging station. Regardless, living in South Florida where solid water never falls from the sky, I've never detected any meaningful difference between using the PCM Charging Planner or just driving to the charging station.
Just to be clear, any control setting that refers to "Preconditioning" or "Precool/heat" is only for managing the Taycan cabin interior temperature. The "Precool/heat" button available on the charging status screen of the lower center console display is related only to activating the cabin climate controls while charging (i.e. you are sitting the car while charging and need the climate control running in order to remain comfortable.) Also, the "Preconditioning" indicator symbol on the instrument panel and elsewhere is only referring to the fact that the Taycan interior cabin climate control precool/heat function or timer is active.
Text on Page 276 of the 2022 Taycan Owner’s Manual is confusingly worded as it relates to charging. Here is my "rewrite" that hopefully is less vague and assumes there is no significant impact on battery life for fast charging.
Charge when the battery SoC falls below 20% and end the charging session when the battery SoC reaches 80%. Avoid charging to 100% except for extended trips where the vehicle will be driven below 80% shortly after charging. Unnecessarily ‘topping off’ the battery SoC or maintaining the battery SoC above 80% for long periods may permanently reduce the driving range. Porsche has specific additional recommendations for charging during long term storage of the Taycan.
You may hear or read conflicting advice from various sources regarding the upper limit, 2020 and 2021 model years apparently recommended 85%, which differs for 2022. Quoting from the page 289 of the 2022 Taycan Owner’s Manual (dated 09/2021) – "Use the timer or profile function to set the high-voltage battery to charge to a maximum battery charge level of 80% for daily use of the vehicle, excluding long-distance trips." The manual also says, "If required, a battery charge state of 100% can be programmed before starting long journeys."
The ambient temperature, as indicated by the value displayed on the left-hand side of the driver’s instrument cluster, can be a factor to consider in deciding when, how and how much to charge. Charging a battery that is too cold or too hot will significantly slow down the speed of charging, and in extreme circumstances shorten the useful life of the battery. Porsche does publish some guidelines regarding ambient temperature and charging, although in practice it is debatable if the guidelines will have a meaningful effect on battery service life.
Charging will be most efficient when the battery temperature is between roughly 80°F and 90°F. However, in our Florida summer climate where the ambient daytime temperature is often within the same range, during DC fast charging the battery temperature can reach between 110°F and 120°F. If DC fast charging in very high ambient temperatures, the charging session may automatically stop with an over-temp error and charging will have to be manually restarted once the battery cools down. EVSEs also have over temperature protections and during a weather "heatwave" on a long-distance trip I experienced charging sessions interrupted by EVSEs with over-temp errors.
Depending on your circumstances and the billing plan you have established with your power company, home charging during off peak hours may offer a significant cost savings. For example, our power company in South Florida offers a plan that includes unlimited charging during nights and weekends at no additional cost. Many wi-fi connected 'intelligent' AC Level 2 devices can manage this automatically. Taycan profile and timer settings can also be used to establish default and/or location based charging SoC targets for charging sessions and then the Taycan will automatically start and stop the charging based on those parameters.
A Profile has a "Minimum SoC" setting value which can override the "Preferred Charging Hours" settings when the Taycan is plugged in to an AC Level 2 EVSE. If the Taycan battery actual SoC is below the minimum SoC setting in the profile, then charging will begin immediately regardless of the preferred charging hours and charge until minimum SoC is reached and then cease. When the actual battery SoC is above the minimum SoC, then charging begins (or resumes) during the preferred charging hours. Set up a charging daily timer with a departure time when you want charging to be completed and the Taycan won’t start until necessary and stops when the "Target" SoC is reached.
Enabling "Direct Charging" mode will disable all profiles and timers, and the Taycan will continuously charge until the SoC reaches 100% or power is removed. This all only applies for AC Level 2 charging; profiles and timers do NOT apply if you are DC Fast Charging, which always functions in Direct Charging mode.
The Taycan PCM has an on-board trip planner suitable for short trips, but for longer trips a popular EV trip planner is A Better Route Planner. There is no perfect solution and experienced EV drivers on longer road trips typically use a combination of tools for planning. PlugShare is better at finding hotels with charging facilities and rates the quality of many charging stations. ABRP is better at optimizing the quantity, length and location of charging stops for longer trips; particularly when preferring EA EVSEs. Branded charging network apps are better at providing near real-time status of their own EVSEs at the charging stations.
One caution for on-the-road logistics in long distance trips: do not trust any single tool for calculating driving distances between charging stations -- always verify the anticipated driving distance to the next station with another source. Also, for a variety of reasons all the various tools seem to consistently underestimate the actual driven miles between two charging stations. A good rule of thumb is to expect each planned segment will be at least 2 miles more true driving distance than the planning tools claim, but much more on rare occasions such as construction detours. When planning charging stops on long road trips a prudent practice would be to always reserve 25 to 50 miles of range as a hedge against unforeseen circumstances.
The most important factor responsible for variability in travel times on long trips will be the location and availability of higher capacity DCFC stations. In practice for longer highway road trips, driving in segments of 125 to 175 miles before charging at a DCFC is reasonably time efficient; easy on both the battery and the bladder, as well as a bit less hassle. Logistically the stops are never quite as time efficient as you might hope, and for planning purposes expect stops on long distance trips to average a few minutes longer than the actual charging session. Planning charging stops combined with eating at restaurants that are within walking distance of DCFC stations can be efficient use of time.
For overnight stays, best to find lodging that offers AC Level 2 facilities for use while you sleep. Prudent drivers will try to plan to arrive at the destination for overnight charging while the remaining SoC provides enough range to reach a DCFC station. That’s because many destinations will have a limited number of EVSEs and, especially by late evening, there may not be any available thus requiring a DCFC shortly after departure the next day. On road trips I pack my PMCC bag with the charger along with a TelsaTap J1772 adapter, the three and four prong 30A to 50A RV adapters, and even the 120VAC pigtail for the PMCC. The extra weight is worth the peace-of-mind about concerns being at an unfamilar destination and unable to charge.
In practice, small variances such as traffic delays or conversely making better time than expected, getting a different amount of charge than planned, and many other factors such as weather and who is driving will ripple through a tight multi-day travel plan with substantial effect. With each successive charging session, the planned future charging stations can change and that will often affect the choice of lodging. The key takeaway is to be flexible!