-
Want to remove ads? Register an account and login to see fewer ads, and become a Supporting Member to remove almost all ads.
Is power for climate supplied by batteries or charger when battery is 100%?
- Thread starter alex_au
- Start date
Tam
Well-Known Member
PACEMD
Active Member
Climate control is coming off of the battery, as always. The battery is then resupplied by the charger. There is no direct connection charger to climate control. Try this outside in the winter connected to the mobile charger. Even plugged in the charge will quickly drop from 100%........
The climate control is 12vDC, so when it's on it is creating a load on the 12vDC bus. Initially that is supplied by the 12v accessory battery, which is quickly resupplied back up to its nominal voltage by the main high voltage traction battery via a DC-DC converter. If the vehicle is plugged into AC the traction battery will then quickly be resupplied back up to its set charge point by the AC-DC charger.
In electrical systems the supply items and load items are attached to a "common bus". A battery is both a supply and a load. But power doesn't flow into a battery and then back out of it if there is supply and load occurring at the same time. It's not like pouring water into a bucket that has pipes on the bottom. It's more like there is pressure on the pipe, and if there are loads where the pressure can exit the pipe then nothing goes to the battery. But if there are no loads then the battery will consume the supply. And if there is no supply but there are loads, the battery will supply the ... supply.
The air conditioner alone seems to be around 1000W, so that along with other internal systems and losses incurred from electrical translations and you'd likely need a pretty high amp power source to keep the main battery topped up. I'm not familiar with the AUS electrical standards but I suspect your standard wall outlet wouldn't be enough.
Incidentally it looks like the original Roadster maybe had a high voltage air conditioning system. I'm not able to find what the Model 3 actually has but I have to suspect it's 12v. I still think Tesla should lead the way moving cars to 48vDC accessory system. SO much money could be saved in wiring.
In electrical systems the supply items and load items are attached to a "common bus". A battery is both a supply and a load. But power doesn't flow into a battery and then back out of it if there is supply and load occurring at the same time. It's not like pouring water into a bucket that has pipes on the bottom. It's more like there is pressure on the pipe, and if there are loads where the pressure can exit the pipe then nothing goes to the battery. But if there are no loads then the battery will consume the supply. And if there is no supply but there are loads, the battery will supply the ... supply.
The air conditioner alone seems to be around 1000W, so that along with other internal systems and losses incurred from electrical translations and you'd likely need a pretty high amp power source to keep the main battery topped up. I'm not familiar with the AUS electrical standards but I suspect your standard wall outlet wouldn't be enough.
Incidentally it looks like the original Roadster maybe had a high voltage air conditioning system. I'm not able to find what the Model 3 actually has but I have to suspect it's 12v. I still think Tesla should lead the way moving cars to 48vDC accessory system. SO much money could be saved in wiring.
Tam
Well-Known Member
Youtube below proves HVAC is drawing 10A from shore power while the charging system charging 0 and the battery gauge does not go down;
Thanks LoudMusic for your explanation here. The car is connected at a public SICHARGE CC AC22 charger. Looks like the car indicates its a 3-phase supply, but voltage only shows 238v (our mains supply here in AU is 240v), maybe that's not me understanding it correctly, but thought it would be 415v or similar. Anyway, really helpful
Attachments
Tam
Well-Known Member
Old or new Tesla HVAC/Heat pump, it has been high voltage.
Page 9 of 19 for Model Y states:
"The heater element is of the heat pump, drawing HV electrical energy from the battery pack High Voltage."
Tam
Well-Known Member
It doesn't matter what your shore power voltage is: 120V, 238V, 400V... The HVAC still uses 400V, high voltage. If the shore power voltage is not high enough, it would step up to meet the high voltage requirement
That’s not necessarily true anymore. It depends on which battery. Some of the newer SR batteries are of thr LFP type, in which case almost the exact opposite applies. Charging to 100% at least weekly is recommended with those batteries.
Given that the OP said they have a 2022 RWD, it’s entirely possible they have a LFP battery.
PACEMD
Active Member
You guys are making this waaaaaaay too complicated. Obfuscation has its own charger. The fact is climate control will drain the battery even when the car is plugged in and charging.
Last edited:
Heating is on high voltage from the battery and takes whatever power it needs for the settings you have. When the battery starts going down, the car will start charging by pulling energy from the charger. If the charger doesn't provide enough energy, then the battery SOC will go down. I don't believe the car directly pulls from the charger. If it did, it would sometimes need to reduce its consumption based on what the charger provides. My LR AWD 3 might pull 6-7kW for heating, plus 6.5-7kW for battery heating in winter. My charger can only provide 11kW, and I don't believe the car reduces its power draw because of that.
PACEMD
Active Member
Similar threads
