Does the battery get heated up by default upon charging?

[Kingske]

This afternoon, I charged my battery from about 61% SoC to its General Profile-set level of 85% (see first picture below). The ambient temperature outside was around the freezing point and the temperature in my garage was 55F/12.5C. Later today, two things happened which I never noticed before: 1) a message appeared on my iPhone that charging was completed whereas I was/am not aware that the Porsche Connect app on my phone was active, and 2) the battery temperature (see second picture below) was a balmy 75F/24C according to the dashboard readout, even though I did not select any preheating or other special settings. Are both events something which always happens but which I failed to notice until now, or is this some new functionality? In case of the former, I apologize for the dumb question.

 

[daveo4EV]

yes - charging and discharging the battery has “waste” heat from the electro-chemical reactions and the electron flow in the wires…so there is some nature increase in temperature when the the battery is “being used”

high rates of discharge cause high rates of thermal increase - do this long enough (say 6 or 7 laps full out at laguna seca) and you can create more heat than the Porsche battery thermal system can compensate for - the battery will reach 132F at which point the computers will step in and limit the maximum discharge rate and there by limit the car’s acceleration and top speed

if you allow the battery to cool back down to below 132F the car will reward you with restoration of “full power” until the battery hit’s 132F again.

but yes there is most certainly heat generated from both charging and discharging - but sometime’s it’s pretty inconsequential - other times it’s enough that even the cooling system can not overcome it.

 

[daveo4EV]

the vehicle will also sometimes ‘condition’ the battery to a better temperature - since charging LiON cells when they are “too cold” lowers their longevity - the temperature rise you observed may not have been entirely due to the charging “load” but rather the car detecting that the battery was being charged raised the temperature of the battery for it’s overall health so that it was charging at a better temp for battery health reasons.

without access to the detailed charging logs we can’t know if the temperature rise was purely due to heat from the charging load, of if the car also used power to raise the temperature of the LiON cells utilizing the Taycan’s sophisticated thermal system - which can both cool and heat the battery as necessary to keep the LiON cells in their optimal temperature range.

 

[NC_Taycan]

If the time you checked happened to correspond to the departure time in one of your timers, that might also explain why the battery was pre-heated, to make travel more efficient. I suspect the charging complete notification is part of the most recent app update, assuming you updated your Porsche Connect app to the latest version, but that's a guess. I haven't charged since I updated.

 

[mc9er]

This afternoon, I charged my battery from about 61% SoC to its General Profile-set level of 85% (see first picture below). The ambient temperature outside was around the freezing point and the temperature in my garage was 55F/12.5C. Later today, two things happened which I never noticed before: 1) a message appeared on my iPhone that charging was completed whereas I was/am not aware that the Porsche Connect app on my phone was active, and 2) the battery temperature (see second picture below) was a balmy 75F/24C according to the dashboard readout, even though I did not select any preheating or other special settings. Are both events something which always happens but which I failed to notice until now, or is this some new functionality? In case of the former, I apologize for the dumb question.

Out of curiosity, what charger are you using?

 

[Kingske]

Out of curiosity, what charger are you using?

Porsche’s PMCC at 40A

 

[Kingske]

If the time you checked happened to correspond to the departure time in one of your timers, that might also explain why the battery was pre-heated, to make travel more efficient. I suspect the charging complete notification is part of the most recent app update, assuming you updated your Porsche Connect app to the latest version, but that's a guess. I haven't charged since I updated.

I do not use the timer function, but you may be right about the latest Connect app version. Thanks.

 

[mc9er]

If the time you checked happened to correspond to the departure time in one of your timers, that might also explain why the battery was pre-heated, to make travel more efficient. I suspect the charging complete notification is part of the most recent app update, assuming you updated your Porsche Connect app to the latest version, but that's a guess. I haven't charged since I updated.

Do you think that’s a function of using a Porsche mobile charger connect (plus the updated Connect App)? Or just an update in the app itself notifying of the “charge complete” (separate from the Porsche mobile charger connect)? I.e. can anyone clarify if you still get these updates when using a third-party charger and not the one provided by Porsche?

Also, I do not have delivery of my Porsche as it is on order (otherwise I would check for myself), but are you able to have the connect app send you notifications / reminders if you forget to plug your car in at night for instance? I know some third-party chargers allow this functionality which is kind of neat

 

[Scandinavian]

This afternoon, I charged my battery from about 61% SoC to its General Profile-set level of 85% (see first picture below). The ambient temperature outside was around the freezing point and the temperature in my garage was 55F/12.5C. Later today, two things happened which I never noticed before: 1) a message appeared on my iPhone that charging was completed whereas I was/am not aware that the Porsche Connect app on my phone was active, and 2) the battery temperature (see second picture below) was a balmy 75F/24C according to the dashboard readout, even though I did not select any preheating or other special settings. Are both events something which always happens but which I failed to notice until now, or is this some new functionality? In case of the former, I apologize for the dumb question.

Interesting that you have not seen that notification before. I have had that most of the time since May last year when I got my car. The only exceptions has been when the cellular signal has been too weak in the garage. But now my OTA module seems out of order so no more notifications since third week in January. Is also noted earlier that my car seemed to contact the Porsche servers at 7.30 every day. This was noted in the app as well.

For you increased battery temperature, I think you might have set a departure time with or without preheating. For home charging I doubt that there would be enough waste energy to heat the battery that much. That would require a hell of a lot of waste energy! Could well be a feature of the car or helped by the new version of the app.

The technical information from Porsche showed the feature of Heating battery was part of the information the car used to prepare for departure! It takes the information from the weather information in the car!

Interseting to hear if it will happen again or for someone else! One very good reason to keep the car plugged in and charge every night anyway.

 

[Doc B]

Interesting that you have not seen that notification before. I have had that most of the time since May last year when I got my car. The only exceptions has been when the cellular signal has been too weak in the garage. But now my OTA module seems out of order so no more notifications since third week in January. Is also noted earlier that my car seemed to contact the Porsche servers at 7.30 every day. This was noted in the app as well.

For you increased battery temperature, I think you might have set a departure time with or without preheating. For home charging I doubt that there would be enough waste energy to heat the battery that much. That would require a hell of a lot of waste energy! Could well be a feature of the car or helped by the new version of the app.

The technical information from Porsche showed the feature of Heating battery was part of the information the car used to prepare for departure! It takes the information from the weather information in the car!

Interseting to hear if it will happen again or for someone else! One very good reason to keep the car plugged in and charge every night anyway.

I agree - this must either be a new feature or the coincidence of correlating with a departure timer. There is always some waste heat heating the battery when you charge, but I’ve never seen my battery temperature, on AC charging, increasing from 12.5C/55F to 24C/75F from just a 24% increase in SoC. At most I would have gone up to around 17C/63F I reckon. Would be great if this is a new feature. I have a 7.4kW charging unit.

 

[Kingske]

Do you think that’s a function of using a Porsche mobile charger connect (plus the updated Connect App)? Or just an update in the app itself notifying of the “charge complete” (separate from the Porsche mobile charger connect)? I.e. can anyone clarify if you still get these updates when using a third-party charger and not the one provided by Porsche?

Also, I do not have delivery of my Porsche as it is on order (otherwise I would check for myself), but are you able to have the connect app send you notifications / reminders if you forget to plug your car in at night for instance? I know some third-party chargers allow this functionality which is kind of neat

Next time, I will use my Mustart travel charger to see whether the “charging completed” notification appears on my phone again.

 

[wemct]

I agree - this must either be a new feature or the coincidence of correlating with a departure timer. There is always some waste heat heating the battery when you charge, but I’ve never seen my battery temperature, on AC charging, increasing from 12.5C/55F to 24C/75F from just a 24% increase in SoC. At most I would have gone up to around 17C/63F I reckon. Would be great if this is a new feature. I have a 7.4kW charging unit.

I have definitely noticed the battery temp increase when using the EA DC chargers. Until this thread I didn't check what happened during my home L2 charging. This morning I connected the PMCC at 24A to a 30A dryer outlet. The battery temperature was 45F and the initial SOC was 45%. I took a peek a few minutes ago. Even at a relatively low charge level 5.24kw, the battery temp increased 15 degrees to 60F at 51% SOC. I am using the General Profile set to 85% (no timer profile).

 

[Kingske]

I have definitely noticed the battery temp increase when using the EA DC chargers. Until this thread I didn't check what happened during my home L2 charging. This morning I connected the PMCC at 24A to a 30A dryer outlet. The battery temperature was 45F and the initial SOC was 45%. I took a peek a few minutes ago. Even at a relatively low charge level 5.24kw, the battery temp increased 15 degrees to 60F at 51% SOC. I am using the General Profile set to 85% (no timer profile).

Same here. Only General Profile, no timer. You are also getting a rather big increase in battery temp for such a limited SoC addition, at 24A no less. Given the bulk of the battery, hard to believe that this is only the result of heat dissipation caused by the charging process itself.

 

[wemct]

Same here. Only General Profile, no timer. You are also getting a rather big increase in battery temp for such a limited SoC addition, at 24A no less. Given the bulk of the battery, hard to believe that this is only the result of heat dissipation caused by the charging process itself.

I was surprised too at the amount of battery temp increase for a relatively small increase in SOC at 24A instead of the 40A that I have at my other place in Georgia. The battery temp has increased another 2 degrees since my post. As mentioned by @daveo4EV the Taycan's battery thermal management system may be at play too to get the battery pack into a better temp range even for L2 charging.

 

[Doc B]

I have definitely noticed the battery temp increase when using the EA DC chargers. Until this thread I didn't check what happened during my home L2 charging. This morning I connected the PMCC at 24A to a 30A dryer outlet. The battery temperature was 45F and the initial SOC was 45%. I took a peek a few minutes ago. Even at a relatively low charge level 5.24kw, the battery temp increased 15 degrees to 60F at 51% SOC. I am using the General Profile set to 85% (no timer profile).

I think I saw another poster who posted some really detailed data from charging (really sorry to whomever that was for forgetting your name - with every day being exactly the same, my memory is shot). It seemed that the battery does pull power from the mains to heat up the battery if it is very cold, up to a threshold, and then starts to use mains power to charge the battery (at which point any increase in temperature is just from the heat dissipation). So, that would explain the quick increase to 60F - would be interested to see whether that temp increase now slows down? Kingske's data was the really surprising one though, since it kept on heating to 24C/75F even though the SoC had not gone up by much which suggests continued pre-heating of the battery - I've just not been able to get my car to do that without a timer so far (or even with a timer, since I do not use them). I'm seriously hoping this is a new thing, as it would be a game changer for Winter weather.

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