Home charging verrrry slowly

[Goldeneyez]

Hello all, we are new to EV’s and just professionally installed a Chargepoint 50A home charger for our 2021 Taycan RWD on a NEMA 14-50 outlet, 240V. The car has always pulled 130-144kwh at EA via Plug and Charge, and I was expecting 9.6-11 kwh based on what I’ve read here and on Porsche’s website. However, it’s pulling 3 kwh (0.1 mi/min). It eventually charges to the set profile (80%), but it takes forever. Any suggestions or ideas about why we’re trickle-charging?

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[madeyong]

Dedicated circuit? I am using the PMCC on a 50 amp dedicated circuit so don’t have any experience with the ChargePoint specifically but on the PMCC there is a setting to select the maximum amps that the EVSE delivers under the setup. If it’s a 50 amp circuit you should make sure your EVSE is set to deliver the full 40 amps and it’s not dialed back for some reason.

 

[Ll312]

First place I’d check is your evse. While I’m not familiar with the ChargePoint evse, you should be able to specify the amperage it outputs. On a 50 amp circuit you should get 40amps. 40 amps x 240 V = 9600watts

 

[mc9er]

I have the ChargePoint homeflex and have had ZERO issues. Was installed by an electrician and I get the 9.6kwh you mentioned. Seems like some setting is off somewhere. You have to adjust in the ChargePoint App as well (otherwise it defaults to its lowest charge speed for protection). In the settings portion of app

 

[Goldeneyez]

Thank you! We readjusted the settings on the app and are now getting 8.3 kwh (0.4 mpm) so moving in the right direction. We’ll keep tweaking it, but this is much better!

 

[daveo4EV]

8.3 kW could be inline/max for 40 amps - 9.6 kW (240 * 40 amps the max charge rate on a 50 amp breaker) - my Taycan yields 8.8 kw during charging from my PMCC - the vehicle reports power being added to the battery _NOT_ raw power being delivered by the EVSE…

9.6 raw EVSE power (your charge point charger) could very well end up as 8.3 kW being reported by the vehicle due to charging overhead and losses…AC/DC conversion, resistance, and slight variation in actual voltage could easily account for the differences…also you might for examply only being getting 9.2 kW “raw” due to voltage levels in your actual home/electrical-system…

220 volts * 40 amps = 8.8 kW raw power
vs
240 volts * 40 amps = 9.6 kW raw power

if your power provider or home electrical system isn’t actually delivering 240 volts then 8.3 kW would be inline with expectations - 240 volts is “ideal” - but in practice depending on a lot of factors (time of day, distance of wire runs, gauge of wire, loads on the grid, etc) voltage in North American can vary from 210 to 250 volts in actual practice…unless it’s dropping below 210 volts then it’s with in “normal” range for residential grade power in North America

(also: you might using 208V which is common commerical power voltage) - 208V * 40 amps = 8.32 kW…

check with your local power company or electrician - 9.6 kW is the ideal raw charge rate in controlled lab conditions at exactly 240 Volts AC - your home is not a ideal lab - real world variations could easily account for slight differences you are seeing…

8.8 kW is the maximum I’ve ever seen from a 9.6 kW charging session w/Taycan…

the maximum “raw” charge rate for a North American Taycan is 48 amps (60 amp breaker) for a raw power level of 11-12 kW - yielding 10.46 kW being reported by the vehicle during the charging session…(unless of course you‘ve specified the optional 19.2 kW charger as part of your Taycan order)

8.3 kW could be expected and completely normal for your situation and is inline with variations due to normal residential electrical power variables.

the simple fact is you will never see 9.6 kW being reported by the vehicle when charging from a 240/40 amp source - 9.6 kW is the ‘raw’ ideal power level - and Porsche’s software shows the power being added to the battery after accounting for normal and expected losses in the AC/DC charging process…

as I said - I know my PMCC delivers a raw 9.6 kW (I have a meter on the charger) but the car shows 8.8 while charging - when charging from my 100 amp Tesla Charger (19.2 kW potential raw power) the in vehicle charge rate shows 10.48 kW (an expected and reasonable amount for a raw 48 amps @ 240 volts - 11-12 kW raw power)

 

[daveo4EV]

charging now - raw power from the grid/meter = 9.6’ish kW according to my home power meter

in vehicle charge rate shows 8.7 kW (due to charing overhead losses expected and normal in any AC/DC battery charging process and completely normal for all EV’s)

measured loss in this case is about 9.3% overhead in the charging process - completely inline with expectations and limitations of AC/DC conversion levels…

 

[daveo4EV]

working backwards from your 8.3 kW number

8.3 kw / 90% = 9.2 kW “raw” power from the chargepoint EVSE…

9.2 kw / 40 amps = 230 volts

230 volts could be completely normal for any residential grade power levels…if that is in fact what is happening - 230 volts actual voltage is inline with “normal” residential power variations or could be “loss” from ideal power coming into your home at 240 volts - but 230 volts is what ends up in your garage due to wire length, quality, circuit-breaker, material-type of wire from your electrical/meter and main home panel to your circuit in your garage where the ChargePoint charger is drawing power…

I visited one home once where incoming voltage from the “meter” was 240 volts - but due to the very very long run and really old wire - it was measuring as 234 volts in the garage due to losses between the main panel and the garage…

230 volts * 40 amps = 9.2 kW
9.2 Kw raw * 90% charging efficiency = 8.3 kW reported in vehicle by Porsche’s charging software.

8.3 kW can be explained by 9.2 kW raw charge rate - which is 0.4 kW variation from “ideal” of 9.6 kW - 0.4 kW variation is a 4.1% variance from “ideal/expected”…not sure you can expect much more from residential grade power and consumer grade EVSE equipment.

 

[Goldeneyez]

Thank you, daveo4EV!
This helps a lot in terms of managing expectations, and also because the charge rate now is actually reasonable. We had a weird situation where neither of us was home
when the installer came due to work conflicts, so we’ve been trying to figure everything out on our own. We just needed to connect to the charger via the app, as you all said. Thank you, all!

 

[Snappy77]

Does selecting "Optimized charging" slow it down even more?

 

[XLR82XS]

Does selecting "Optimized charging" slow it down even more?

Only for DC charging.

 

[Scandinavian]

Only for DC charging.

I thought Optimised charging only worked with AC and neended extra Equipment like the Home Energy Manager. It can work well with Solar Panels etc.

*corrected spelling

 

[NC_Taycan]

BTW if you are in the vehicle with systems on (e.g. HVAC, audio), the incoming power from the EVSE will be partially consumed to power those systems. You might have 8.8 kW coming in, less 400W for everything else, so getting 8.4 kW into the battery. What is shown on the center console screen is the battery charging current (8.4 kW in this example).

 

[PDACPA]

Just received my Chargepoint HomeFlex and hooked it up last night.

 

[XLR82XS]

Damn man - 60 degrees! 8.67kw is good.

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