Battery Cooling Ever Come On During Level 2 Charging?

[STS134]

Has anyone ever heard their battery cooling system in their Outlander PHEV come on during Level 2 charging, or when simply plugged in to a Level 2 charger after the car is done charging? I know that the cooling comes on when using CHAdeMO but I have never heard the fans or compressor start up during Level 2 charging.

 

[Superflan]

Open the hood and look at the coolant tank it’s disturbing

 

[STS134]

Looked under the hood this morning. It wasn't very hot, and I didn't hear any fans, but the coolant in one of the tanks did feel warm. Maybe the pump was operating without the fans or compressors?

 

[HHL]

Looked under the hood this morning. It wasn't very hot, and I didn't hear any fans, but the coolant in one of the tanks did feel warm. Maybe the pump was operating without the fans or compressors?

That would be cooling the charger, the coolant circulates through that.

The battery is cooled by an evaporator from the aircon compressor.. that is unlikely to be required in level 2 charging.

 

[STS134]

That would be cooling the charger, the coolant circulates through that.

The battery is cooled by an evaporator from the aircon compressor.. that is unlikely to be required in level 2 charging.

Really depends on the ambient temperature. The battery cannot be cooler than the ambient temp, and if I'm Level 2 charging on a very hot day and it's 38C in my garage, I would expect the AC compressor to come on. Teslas apparently *always* control the temp on their battery packets, even when the car is off, unless the battery charge level falls below 5%. Now a PHEV doesn't have the capacity to run the AC compressor for hours, but I would expect that the Outlander PHEV should at least be able to do it when charging (as the power is coming from the mains at that point). Given the roughly 10-20% power losses that you get when you put energy into and take energy out of a battery, and if the system is charging at around 3 kW, I would expect around 300-500W of heat to be generated in the battery and that the cells would be at least 3-5C above ambient temperature...and in the case of 38C ambient, 43C is way too hot for those cells, especially if you can run the AC and keep them at 28C.

 

[HHL]

I think you'll find that the charging efficiency of the battery is rather better than the figures you quote. In fact, it can be as high as 95% for Li-Ion (not including losses in the charger). At the maximum charge rate of Level2 (about C/.25), very little heat would be generated. I have never noticed the aircon compressor coming on during charging, and it can get a bit warm at times here in Australia. I think the fan in the battery pack would come on first. Anyway, interesting subject.

 

[elm70]

Outside temperature, cabin temperature and battery temperature are not tight correlated

I often find in summer, after leaving for 8h my car under the sun ... outside temperature of ~33 deg ... cabin temperature ~45deg ... but battery at the start is around ~26 deg

The battery is relative well isolated and always on the shadow .. so not much impacted by outside temperature

After 20min drive ... the temperature of battery rise ~8 deg ... and if I recall right only above 35deg the battery "cooling" kick in

About the power lost on charger ... yes total efficiency is around 90% ... but biggest power lost is inside the charger and not on the lithium battery .. charging at 3kw battery rated 12kw .. so at 0.25C .. this does not cause any increase of temperature of the battery ... per experience charging my hobby lithium batteries at 1C, these never change their temperature (ok .. normally these are never less then 10C or 30C capable battery so with much lower IR .... our PHEV battery is a 5C capable battery .. anyhow charging at 0.25C should not cause any noticeable difference in cell temperature ... unless we consider very cold battery temperature which cause an increase of IR)

 

[STS134]

Yeah, I would expect fans to come on first, then AC if fans are insufficient. Interestingly, a friend of mine drove his Cayenne S E-Hybrid to my house, about 1 week after I got my Outlander PHEV, and at the time, I hadn't yet installed my Level 2 EVSE. I plugged my Level 1 (120V) EVSE into his Cayenne, and the front grill slats opened up and the fans and pumps started up to cool the battery. It was an abnormally hot day. Ambient temp was around 35C, and the car had just been driven, but still, it was only Level 1! Now I have never charged my Outlander PHEV in those types of conditions (haven't had a chance to, because it hasn't been this hot recently) but I really wonder if there would be any sort of cooling delivered to the battery at all when it gets that hot, whether via fans or AC or both.

I am a bit preplexed by Mitsubishi's decision to go with air cooling rather than liquid cooling. Liquids generally have a higher heat capacity than air, and can deliver more consistent temperatures, especially if the pumps/fans are on. Obviously this isn't a Leaf, with its only passive air cooling, and at least has active fans and AC systems helping to cool the battery, but if the fans aren't coming on during L2 charging on hot days, I'm not sure that the system is doing its job (which is why I asked if anyone has ever heard the fans or compressors come on during those conditions).

 

[ThudnBlundr]

VW and Porsche seemed to survive successfully for many years using only air cooling. It also avoids having liquids and high voltages in close proximity!

 

[STS134]

Well I just found this video:
https://www.youtube.com/watch?v=svf1b-51OeM

This guy claims that even when it's hot, the battery cooling fans and AC compressor do NOT come on during normal (level 2) charging. If that's true, it's pretty disturbing. I can understand not running the cooling system when the car is parked like the Tesla vehicles do; a PHEV does not necessarily have the energy reserves to do it. But not starting the battery cooling system when the car is connected to the mains? No excuse for that. So what are the thresholds for turning on the cooling system while charging? I think it should be something like > 30C, fans on, and > 35C, AC on.

 

[Woodman411]

I am a bit preplexed by Mitsubishi's decision to go with air cooling rather than liquid cooling. Liquids generally have a higher heat capacity than air, and can deliver more consistent temperatures, especially if the pumps/fans are on. Obviously this isn't a Leaf, with its only passive air cooling, and at least has active fans and AC systems helping to cool the battery, but if the fans aren't coming on during L2 charging on hot days, I'm not sure that the system is doing its job (which is why I asked if anyone has ever heard the fans or compressors come on during those conditions).

Probably cost related. According to this article, we get an idea of thresholds. For Hyundai, air-cooling is sufficient for 27kWh, but not 64:
https://www.greencarreports.com/news/1116041_5-things-about-the-2019-hyundai-kona-electric-we-learned-at-the-ny-auto-show

This doesn't answer your question though of why the fans don't come on for L2 charging when ambient temperatures exceed 30 or 35C's.

 

[dogman12]

Well I just found this video:
https://www.youtube.com/watch?v=svf1b-51OeM

This guy claims that even when it's hot, the battery cooling fans and AC compressor do NOT come on during normal (level 2) charging.

Please describe what app this fellow is using to monitor (everything.) I want it!

 

[elm70]

Well I just found this video:
https://www.youtube.com/watch?v=svf1b-51OeM

This guy claims that even when it's hot, the battery cooling fans and AC compressor do NOT come on during normal (level 2) charging.

Please describe what app this fellow is using to monitor (everything.) I want it!

PHEVWatchDog from Google Play Store ... only available on Android

This apps has been done by a member of this forum here, taking some info from this forum as well (mainly from anko)

 

[elm70]

About battery cooling ...

I just notice that on my car it does kick in only when driving, and only when 1 module reach or go above 35C

About how good is this cooling ... I have my doubt ... on a long drive I can see the coolest module down to 20C with the hottest module up to 35C ... so 15C difference between .. a sign that the cooling system is not well balanced .. this may also explain why some of my cells have higher IR then thers

 

[Trades46]

I consulted a Mitsubishi technician in Canada during an event about this question. Please note this may only apply for the MY2018 (North America never received the PHEV until this year).

According to what I learned, the battery cooling would kick on anytime the charge plug is plugged in & actively charging or when the car is on; the only time the cooling won't be active is when the car is sitting still while off under the sun. As long as the battery temperatures reaches a certain threshold, even a Level 1 charging connector would trigger the cooling fans to operate.

 

[STS134]

Well I've been tracking battery temperatures during charging. It does appear that L2 charging barely moves the temperature. It rises by 2-3°C at most, so that's probably why I don't hear the cooling come on. FWIW, Tesla uses an activation temperature of 52°C for active cooling. Fans come on above 30°C, but no active cooling until the pack temperature hits 52°C. https://teslamotorsclub.com/tmc/threads/tesla-thermal-management-system-explanation.88055/

 

[Grigou]

My experience in July : temperature about 28 °C, and charged the battery just after driving (battery rather hot I suppose).
No fan during charging. I stopped the charge after about 2 or 3 hours, before the battery was full, and started the car : the fans started immediately, and for a while. I remember the temperature for the hottest cell (or module ?) : 38 °C