Want to buy a Model S but ... only 100 Amp 240 volt incoming circuit to the property (condo)

Want to buy a Model S but ... only 100 Amp 240 volt incoming circuit to the property (condo)

Here is my problem :

I live in a condo and have my own garage. The HOA is ok with me installing a power outlet and fuse (nema 14-50) provided it is done with a permit by a licenced electrician. Even though the garage is for my exclusive usage only it is considered common property.

Here is the problem : the Main breaker for my unit sits in the shared utility closet. This is a 240 volt 100 amp circuit.
the panel is shared with 7 units and is a 1200 amp panel.

According to the NEC and California electric code a load calculation is in order to figure out if the 50 amp fuse and Nema 14-50 can be installed or not.

And this is where the misery begins...
i can't make heads nor tails from this calculation and get a lot of conflicting information.

Every major appliance in the house is GAS apart from an oven in the kitchen.

Here is my fuse box breakdown
15 amp : hallway / entry/ living room
20 amp : FAU (furnace and air handler)
20 amp dining area
20 amp microwave
20 am kitchen gfi 1
20 amp kitchen gfi
20 amp garage gfi
20 amp house gfi (bathrooms)
15 amp bedroom 3
15 amp master bedroom
15 amp bedroom 2
15 amp entry and stairwell
30 amp 240 volt for Oven ( two linked fuses 30 amp each )
20 amp garabge disposal
20 amp dishwasher
40 amp AC 240 volt ( 2 linked fuses )
20 amp laundry
20 amp laundry

i have the real appliance power rating:
microwave 1650watt
oven : 2700 + 3600 watt
dishwasher : 10.5 ampere
clothes washer : 10 ampere
clothes dryer : 6 ampere

can someone figure this one out ?
i did a couple of excercises and always end up around 24000VA ( sometimes 100 Va below, sometimes 300 Va above )


mrspaghetti | 16 October 2013

Best thing would be to have a licensed electrician come out and bid the job for you. I'm thinking he'd have to do the calculation for his bid, so you'll find out if it's ok out not.

It seems to me you should be able to install it, though you might not be able to use it when the AC is on without dialing down the amps.

tes-s | 16 October 2013

I think you will need an electrician, but pretty clear to me that you do not have enough power for an additional 40amp continuous load.

If the AC and oven are on at the same time that would be about 50; add 40 for the Tesla and that leave 10 for everything else.

I think the question for an electrician would be how big a breaker can you put in for EV charging?

If there are 7 units and 1200A available, how come you only get 100? Do 4 get 200 and 3 get 100 and 100 for the association (outdoor lighting, for example)?

shop | 16 October 2013

The panel might be able to handle it. Electricians do a percentage load for all 120V loads (all those 15 and 20A breakers), and then add up total combined load for 240V appliances. But even if it can't, upgrading the panel to a 125A or 200A panel isn't the end of the world. The condo in total has more than enough power. Time to get quotes from electricians.

vincent.himpe | 16 October 2013

to clarify :

- the main panel is labeled 1200 amp , but each unit only has a 100 amp fuse. i do not know what is the real power coming in to the panel .

upgrading is most likely not possible as i would have to run new cabling from the meter panel (where the 100 amp fuse is) to my fusebox. that is over 100 ft ... and that cable runs through the other properties. (i'm opposite corner )

Besides, i do not want to spend 2 or 3K on infrastructure of a property i may leave 3 or 4 years from now...that is wasted money.

jat | 16 October 2013

You can do a few things:
a) use the charging time to charge in the middle of the night, when the oven and dryer aren't going to be running. If you fail to do it properly, you will trip your main breaker.
b) run a 30A outlet instead, such as a NEMA 14-30. You will get a slower charge, but it will be plenty sufficient for nearly all of your needs.
c) pay to upgrade your panel to 200A. The main panel is 1200A and only 7x100A subpanels off it, so it shouldn't require any change beyond the wire to the main panel and your subpanel. It won't be cheap though.

Ideally, you would be able to find out how much power you run through your main breaker with everything turned on - you may find an electrician who can measure that, or you can get something like the TED5000 to monitor it. That would let you know just how much room you have, though it sounds like your code is going to require a calculation to their satisfaction anyway.

mrrjm | 16 October 2013

If the town you are in requires a permit then it may not be possible. Another 50amp circuit will trip the 100 amp breaker under the right conditions. If a permit is not needed, which is what I think, then just have the electrician install the circuit. Don't charge the car is the ovens and ac are on. Now that I read all your loads that should be a 200amp panel. HHMM. Get an electrician out there.

jat | 16 October 2013

@mrrjm - the existing circuits can already trip the main breaker under the right conditions. That isn't a safety issue, as the breaker in the main panel protects the wire and subpanel.

Bighorn | 16 October 2013

I'm getting along just fine with a 20A/240V outlet--adds 12 MPH which should suffice unless you have a long commute.

Roamer@AZ USA | 16 October 2013

You have a problem that will be repeated a million times in the next few years. Not easy to solve. The sad thing is I see very little new construction that is planning for this.

One upside is that many of the Tesla buyers today are involved in the real estate development market. As they solve problems charging their own cars the light will go on that future developments need to plan for this electrical load.

Tâm | 16 October 2013


Coordinate an electrician with your HOA is best.

If there's an existing 110V outlet in your own garage (at least there's 1 for the garage opener) then may be you can use it if your commute is not that long.

You could max charge with HPWC in 5 hours after work on Friday night, then off you drive to Grand Canyon National Park early Saturday.

With 110V, you have to fill up your battery on Friday, Saturday, and Sunday to get it ready for a work week starting Monday. All work and no play for you, unless....

Unless you can access Supercharge then you can play all you want by just stopping by it!

jbunn | 16 October 2013

It's going to come down to what the electrician thinks he can get in the box. Don't rule a Tesla out until you have him take a look.

I don't have any charging in my apartment at all, and I manage quite well.

lammersc | 16 October 2013


What is the 240V 40-Amp circuit you have listed in your fuse box for? You did not designate anything assigned to this?

You might ask an electrician if he can install a switch on your oven circuit, and run a second leg out to the Garage. I am not an electrician, and do not know if this is against code, but you could have it power one circuit or the other - charging the MS after dinner etc. It may be an inexpensive option.

shop | 16 October 2013

Unless you do a lot of driving every day, you don't need a full 50A circuit. A 30A circuit or even a 20A 240v circuit will most likely suffice. Ask an electrician what the max he thinks he can put into your existing panel and go from there. How much driving do you typically do?

brian4591 | 16 October 2013

After reading all the comments I would believe Jat is the closest in a correct answer. The charge at night part only.

As long as you set the charging at night (Which can be set from within the car settings) then you will/should have no problems at all. The only thing that might run at night would possibly be the AC and the dryer. Avoid using the dryer during your charging time and everything "should" be great!

Email me if you would like more info on how electrical load calculations work.

Brian Wuttke
BW Electric

PapaSmurf | 16 October 2013

i agree that 20 amps or 30 amps (240 volts) is likely enough for home charging. That will put over 100-150 miles of range on our car each night. Most people don't arrive at home with an empty battery. Odds are that you are doing way less than that each day. Think about your daily commute and if that works.

vincent.himpe | 17 October 2013

I am not worried a out my 'real power draw' . It's the permit i am worried about !
Be ause this is in a common area a permit is mandatory. It needs to be signed off by an inspector. These guys require load calculations.

My normal power consumption in the house ivery low. The bedroom , halway and kitchen circuits don't co sume anything. There is mereley a few clock radio's and a few led lightbulbs on those... I dont have any small kitchen applieances like toaster oven.

My peak daytime load would be AC running and washer and dryer and dishwasher and oven running. That would draw 87 ampere total. Add some small stuff like the tv and a computer or two and you climb to 95 ampere.

Now, at night , when the tesla is programmed to commence charging after 10pm and terminate before 4am
All that stuff falls away. Only the AC would run. And thats 30 ampere... Add some grossly overstated, vampire draw from clockradio and other stuff in standby and you end up at 50 ampere.
More than enough margin to feed 40 amp to the tesla.

So technically i can manage this perfectly.

The problem is not that. Its convincing the code inspector to sign off on the install !

jat | 17 October 2013

Well, none of us know your local code or exactly what the load calculation looks like. If it's anything like my city, getting access to it is quite hard - I finally found I could look at the local code physically in the city office during business hours.

Your best bet will be to call an electrician who can do the load calculation and probably won't charge you more than an hour of your time, and might not even charge you for it if you get them to do the work.

Andrew_OH_S60andS70D | 17 October 2013

I had the same issue. However, at the same time I decided to change out my electric stove for a gas stove. I got a great deal at Best Buy, and it was not that much to run a gas line to the kitchen. I much prefer cooking on a gas cook top. This freed up the circuit that fed the old stove. My breaker panel was in the garage anyway, so running the line and installing the NEMA 14-50 was inexpensive as well.

petero | 17 October 2013

Vincent. I agree with the others about getting a couple of electricians' opinion/bid. Keep in mind, you will be charging in the off hours (12AM-7AM) when you will have minimal draw. I think you are fretting over a hypothetical problem.

mrspaghetti | 17 October 2013

Wait a second, if your only electric appliance is the oven then just use the circuit dedicated for the dryer for charging. Or, check if your oven has a gas feed capped off behind it and buy a gas oven, then use that circuit for charging.

vincent.himpe | 17 October 2013

Switching out the electric oven is not an option. This is a wall mount oven and not a range. (the oven and burners are separate in my kitchen. Burners are gas. oven is electric.

There are no wall mount gas ovens in single unit. i checked all the big manufacturers like Samsung, GE , LG Whirlpool and many others. Nobody makes this.

So that avenue is closed.

Now. Anyone got experience charging the car from a a 14-30 outlet ?
I may be able to get away easily by having a 14-30 circuit added. the 14-50 will be very difficult.

There is other confusing things in the electical code.

According to California electrical code a Level-II electrical vehicle charger (240 volts-40 amp) needs to be permanently wired. But the Tesla does not use a Level-II charger (unless you get the 80 amp charger) . It only uses a 240 volt power outlet... So what do i need to get a permit for ? for a dryer plug ? Do i even need to mention that this is to charge an electric vehicle ?

The problem is the electricians i talked to have no experience with Tesla cars... so they don't know what to do.

somebody should have the answer to this one.
- How to correctly declare what you are installing : is it an EV charger ? is it a dryer outlet ?
- Get the appropriate permit
- Do the load calculation
- get it installed.

DTsea | 17 October 2013

If you have a clothes dryer, you could install the 25A dryer plug for the model S- the extra adaptor is $50 or something. I charge at 20A (less loss due to heat in charging) and it's plenty fast.

DTsea | 17 October 2013

Oh and in my state any electrical work needs a permit. Good news is, the Feds give you a 30% tax credit on the work, and my state waives sales tax for 'electrical vehicle charging infrastructure.'

mrspaghetti | 17 October 2013

You don't need to discuss with the electrician what is being charged by a 14-30 outlet, just like you don't need to tell him whether you plan to plug a blender, toaster or whatever into a 110 outlet. This is not a dedicated EV charger, it could be used for absolutely anything - if not by you, then by future residents of the property.

mrspaghetti | 17 October 2013

(I hit submit too soon...)

So an electrician doesn't need to know anything about Tesla cars any more than they need to know about blenders or toasters.

lammersc | 17 October 2013


The switching for the oven would not be ideal, but I assure you it could be done. I am not an electrician, but I am an Electrical Engineer, I just have no experience in residential wiring and NEC code.

If the oven switch is not an option for you, you could install a level-II charger. I read the Specs on the J-1772 connection, (which is an adapter included with the Tesla Mobile charger that comes with the vehicle), and they are supposed to be able to handle up to 80-Amps. If you were going to go to this length, however, you might as well install a HPWC. Whatever you do, it should increase the value of your condo. This of course would require tapping in to the Main Panel and running another 100-Amp line to your condo, and would be expensive.

I also received an advertisement e-mail this morning, from a company that is building EV charging infrastructure, and it looks like they are working in California. I am attaching the link for your reference. You may be able to talk the Condo management into installing a community charging station/stations. In any event, check out the link. With the CHAdeMO adapter coming soon, it may be an option for a Level-III High power DC charger for your Condo community. With the number of EVs in CA, I would think the management would be open to it.

good luck

Andrew_OH_S60andS70D | 17 October 2013

One more suggestion. We have another home, where the dryer is located just inside the door from the garage. For a while, I used a very heavy extension cord and an adapter to plug into the dryer plug. I had an electrician install a switch so that the power coming to the dryer could be diverted to a line in the garage, where another receptacle was mounted for the car. I leave it switched to the car plug unless I need to use the dryer.

shop | 17 October 2013

Your are getting yourself tied up in knots. By code, you don't need to know what will be plugged into a standard electrical plug. Just ask for a nema 14-30 and be done with it. By the way, you haven't answered my question, how much driving do you do?

shop | 17 October 2013

Also, people that are saying, well just charge at night, so there is no problem are also missing the point. If you need/want to get a permit, then the code assumes the plug can be used any time of the day, because at some point, it will, whether by accident or design.

DTsea | 17 October 2013

@mrspaghetti, actually you should tell him it is to charge a car. Code in my state is pretty specific about breaker vs continuous draw because the car will draw high power steadily for hours.... whereas the dryer or oven heaters go on and off - dont have the steady state draw that a car does.

shop | 17 October 2013

@DTsea, not correct. A NEMA14-30 can deliver up to 30A. It is up to whatever you plug into it to follow the code from there on. A Tesla NEMA 14-30 adapter will only draw 80% of 30A, or 24A. The electrician doesn't need to know what is plugged into an outlet, because you can plug anything into that outlet.

jat | 17 October 2013

I charge on 10-30 and 14-30 outlets whenever I travel out of town to friends and family -- it takes about 14 hours to charge from 0 to full, but you are very rarely going to be in that situation.

You are just getting an outlet installed, so if you don't need a permit for that you just call an electrician and have it done.

vincent.himpe | 17 October 2013

My daily commute is only 30 miles. I can perfectly get away with a 30 amp circuit.
its the weekends. i love going to Carmel or monetery. But since i can pick up the supercharger in gilroy on the way back , pump the car half full there and top it off at home even that is not a problem. ican keep the battery completely full at all times.

Installing a switch may actually be a good idea. the Oven has an existing 30 amp 240 volt breaker.
if i install a switch to select between 'oven' and 'car' i don't need anything . i use that oven about 4 times a year...
switching it out is a no-go . as i said it is an in-wall single unit oven (burners are a separate ,gas, appliance and mounted elsewhere ) and nobody makes gas powered in-wall single unit ovens ( double yes , single no , and i don't have room for double unit)

The electric code is weird. According to city ordnance you need to request a permit to install a level-II EV charging system. But.. the Tesla doesn't use a charging system. The tesla only has an extention cord you can plug into 100 or 220. For all purposes the tesla can behave as a microwave (110 volt 15 amp) , as a clothesdryer (20 amp 240) or as an rv (40 amp 240)

shop | 17 October 2013

Yes, you don't install a level 2 charger for a Tesla (unless you install the HPWC). Instead, it is just a receptacle which you plug Tesla's UMC into which acts as a portable charger.

If you went with a transfer switch, you could intercept the oven wire and use that circuit. Doing it this way might result in not needing a permit since you wouldn't be touching the panel.

Brian H | 18 October 2013

I advised evgo to lose their logo. To anyone used to a Tesla, it looks like a dumb cartoon of a CrippledCartCar.

jat | 18 October 2013

Like I said, I use dryer outlets when I travel long distances. If I am staying overnight and leaving immediately or if I were going up and back in the same day, it could be a problem if I am at the limit of the range. But, usually it is more like go there Friday night and come back Saturday night or Sunday afternoon, in which case the 24A charging is more than sufficient.

I wouldn't bother with a switch -- if you really care about it, you can just flip the breaker for the oven off and the breaker for the car on.

Joel N. Weber II | 18 October 2013

jat: my understanding is that if a breaker is not explicitly described as a switching duty breaker, that it is probably not designed to be cycled on and off more than 100 times in its lifetime, and exceeding that limit can increase the risk that it will fail to shut off the power in an overcurrent situation. Therefore, if you're going to switch the breakers on and off all the time, you ought to make sure that the breakers are switching duty breakers.

brian4591 | 18 October 2013

Holy crap! There is a lot of crazy back and forth information in here.

First off: YES you technically need a permit. Any time a new wire is run a permit is required. Changing a plug, switch or light fixture you DO NOT require a permit.

Second: Talk to a local electrician who you might want to do the job. He/she will be able to call the city/inspector and ask what the inspector would like in this application to accommodate the local code rules.

Third: A 30A breaker does NOT pull/carry 30A through it!!!! Same goes for every breaker. Circuit loading is calculated at us MAXIMUM 80% of their rating. 30A breaker is only allowed to be run at 24A. That said the actual use might only be 10A being used. You can not determine load by counting breakers!!! There is a precise formula for calculating home electrical demand. I am not going to explain it as it is very long. Also my take on home demand is that the demand calculations should be changed as a lot of things are now energy efficient and specified in the demand calculations (ex. LED lights, energy efficient appliances, etc)

Fourth: No brainer. Putting a electric vehicle charging receptacle or HPWC in is not a safety issue if done properly. If the wire is sized right, the breaker is correct, and it is wired correctly then nothing can be harmful. What can happen is: the main breaker for the house could trip. This means you have too much load while charging your car. Solution: Don't run your (fill in the blank load) while charging your car. Ex. Oven, Dryer, Jaccuzzi, etc.


Message me if you would like more information.

*Disclaimer: All information provided is based on Canadian Electrical Code and my personal experience. I am not an associate of Tesla or SolarCity and information should be used at your own discretion.

Brian Wuttke - Owner
BW Electric
13841 Malabar Ave
White Rock, BC V4B 2X8

Brian H | 18 October 2013

No messaging on this site. You may get some emails, tho'.

triss1 | 18 October 2013

I had a similar issue and put in a 14-30. In my case the commute is about 40 miles. The car charges in about 2.5 hours every night.

jat | 19 October 2013

@brian4591 - The car already takes care of derating the circuit by 25% for continuous load. So, it will only use 24A on a 14-30 plug or 40A on a 14-50 plug, etc.

In the US, permit requirements vary by locale. In some places, a permit is not required if you don't touch the main breaker box. In this case, since the new circuit would be going to a subpanel, it may or may not require a permit depending on the local jurisdiction's codes.

For example, at my house the codes are such that any work done by a licensed electrician is required to be permitted, but the homeowner is allowed to do the work without a permit if it does not involve anything inside the main breaker panel (personally, this seems backwards - I would want the work done by homeowners to be inspected more than that of licensed electricians). Since I have a subpanel in my garage, I can do all the wiring there myself without a permit (though I did get an electrician to do the HPWC wiring, since on a 100A circuit a bad connection can generate a lot of heat quickly).

dtesla | 19 October 2013

You can dial the MS to charge at whatever max amps you want. An electrician should be able to help you determine what should be your max charge rate. If you trip the breaker you can dial it back a little further. You won't have the change settings when charging at different locations since the MS remembers your charging setting per location. As mentioned above.... charging at night will allow you to dial the car to a higher setting. I would recommend you get the largest amp plug you can. And dial it down at the MS. This give you the option to dial the charge for the car up as your current consumption allows. (i.e. if HVAC is off, in the spring or fall, you can use that part of your power budget to charge the car.

The electrician can also put a device on power cable the can read your power consumption. The procedure 1) put the device on the power cable 2) Turn everything on and take a reading. My guess is he will probably know off the top of his head.

It is also a good idea to only use a max of 80 amps of your 100 amp service. In most, if not all areas, this is required by code.

Sudre_ | 19 October 2013

brian4591 is right. The issue here is the load calculations. I see them all the time on electrical prints. A 20 amp breaker's load calculation is never 18 amps. The calculation is based on what the breaker is used for. I have installed hundreds of 225 amp panels that have 42 breakers all rated at 20 amp. If I were to just add up the 20 amp ratings it would be 280 per phase amps! (commercial three phase)

The calculation requires an Electrical Engineer to review your loads.
A good example.... Your oven never draws more than 15 to 20 amps. A 30 amp outlet was installed because that is standard. Back in the day old electric ovens had very high surges. Your oven should have a kW rating on it somewhere.
The A/C draw changes based on the temp outside but it should also have a rating on the condenser.

My load calculations on my panel schedule have number like 13.8 for my electric dryer. 1.4 for my refrigerator.

My panel appears as though it can draw 270 amps if everything was turned on at the same time but that never happens. For example I have an electric furnace... the furnace and A/C do not run at the same time. I have never tripped my 200 amp main in the 22 years I have lived here.

(##) is calculated load

15 amp (1.1) : hallway / entry/ living room
20 amp (7.9) : FAU (furnace and air handler)
20 amp (4.3) : dining area
20 amp (14) : microwave (I think this one is a mistake. too high)
20 amp (1.1) : kitchen gfi 1
20 amp (2.1) : kitchen gfi
20 amp (1.7) : garage gfi
20 amp (0.1) : house gfi (bathrooms)
15 amp (1.2) : bedroom 3
15 amp (13.5): master bedroom (my wife likes plugging in a space heater)
15 amp (0.1) : bedroom 2
15 amp (0.1) : entry and stairwell
30 amp (12) : 240 volt for Oven ( two linked fuses 30 amp each )
20 amp (2) : garbage disposal
20 amp (5) : dishwasher
40 amp (15) : AC 240 volt ( 2 linked fuses )
20 amp (4) : laundry
20 amp (4) : laundry

Total of 89.2 across two phases. Calculated load per phase 44.6 amps. Barely room for a 14-50 outlet.
These are based on similar labels in my panel. The numbers are calculated by an electrical engineer based on what the breakers are used for. An electric car 14-50 would probably be 40 amps (I'm guessing) add to the calculated load. That'd be 84.6. 4.6 over the 80% rating of the 100 amp main (unless the main is fused).
NEC has changed significantly since my load calcs in 1993.

I think a 14-30 should be fine with no issues. Heck I would go for the 14-50 personally.

vincent.himpe | 19 October 2013

Right. So here is the finite answer.

I went to the City Buidling planning and had a meeting with the building inspector and the electrician.
In my situation with the following premises:

- 100 ampere main breaker on a ALCAN 1 AWG Stabiloy feed cable (rated at 110 A )
- Two existing 240 circuits : 1 40 ampere circuit for HVAC and 1 30 ampere circuit for 1 PERMANENT load

it can NOT be done. A load calculation was done and the total load of such an installation ends up at 88 Ampere.
Adding a 30 ampere circuit for a PERMANENT load ( an electric vehicle is ciunted as a permanent load. Anything with a potential of running more than 3 hours per day is counted as permanent ) is not possible.

So, the outcome is : My existing permanent load has to go !
In my case this is an electric range. I just placed the order for a gas range and the electrician is scheduled to disconnect the wires from the existing 30 amp fues and come install a NEMA 14-30 in the garage. ( the fusebox is in the gerage and the outlet will be mounted 1 foot below the fusebox. since the fusebox is on the drivers side of where the car will beand the Tesla cable is 18 feet long the problem is solved. )

So, i'm gettin me a tesla !

This is what the code inspector told me :

A house or condo with a 100 amp feed is made for 2 permanent 240 loads : a HVAC and either an electric dryer or an electric range. That's it.

Many people wanting an EV find out it is problematic with such a feed. Even worse , EV's requiring a dedicated charging station (like the Leaf) face another problem : Such a station is not allowed, according to north american electric code, to be plug-in. It needs to be hard-wired. Which, in many instances, means running ducting , secondary panel and other things. If you are in a condo : be prepared to fight the HOA to get an architectural release ... By law they can't block you , but they can throw up barriers that everything must be hidden (which means ripping out drywall , putting new one in , painting ... things get very pricey very quickly. Let alone all the legwork and lost time getting paperwork done.

The deicision was very quick for me: ditch the electric oven. it was 12 years old anyway. I'd rather drive a Tesla every day than have an oven i use twice a year.

vincent.himpe | 19 October 2013

By the wy, the load calculation was done ,as Sudre_ wrote, using the real power draw from my appliances nameplates. Washer : 10 ampere , Dryer 6 ampere . Microwave doesnt count as it is below 1750 VA , HVAc is 25 amp , Dishwasher 1200VA.
The killer in my case was my electric oven. That beast is 6.3 Kilowatt or 26 Ampere ...
So i swap the 26 amp for the Oven with 26 Amp for the Tesla.. problem solved. No new breakers needed . No hassle.

shop | 19 October 2013

And people wonder why new houses cost so much. Over engineered, over built, safety margins waaay too large. Anyways, glad you found a solution.

jat | 19 October 2013

BTW - there are plugin J1772 EVSEs available, and you can also have the LEAF EVSE converted to support 240V use as well as 120V.

Anyway, congrats on working it out.

Earl and Nagin ... | 19 October 2013

Once the inspection is done, you can put the range back in :-)
Just make sure you don't try to bake and charge at the same time.