I know there are other posts related to this and I have read quite a few of them. This idea of this post is to focus on how one can set up to actually use a model 3 to power a freezer for a few days, or even a week, during a power outage. There are two possible ways to approach this that I know of and I would love to hear discussion of which way is best and why, as well as the drawbacks or risks associated with either way. To be clear, this is not V2G; the goal is simply to have an extension cord running from your parked model 3 to your freezer (and/or refrigerator). I am thinking some of the key questions are where to do it (in the frunk or the back seat, for example), how to do it (what inverter to use...?) and also: is it a good idea at all? What are the drawbacks, pitfalls and risks.
As I understand it, and I am a fairly new model 3 owner without a long history of Tesla experience, in the model 3 there are two places where one can tap into power. (I am leaving out the 12 V adapter in the console since it is fused way too low). One is in the frunk by connecting directly to the 12 volt battery. The other, I believe, (hoping someone can confirm or dispel this) is under the back seat where there are some power taps? Is this true?
Once a location is chosen, I believe one could connect an inverter that converts 12 volt dc to 110 AC. I don’t think that puts too much load on the traction battery, but it could make the dc to dc converter work pretty hard, and I wonder if that could lead to a failure of the dc-dc converter at some point. I don’t know if the car would have to be “on” for this to work. I am thinking not, since the traction battery will charge the 12 volt battery as needed even when the car is parked and locked. Does this seem like a reasonable choice for the inverter*? Would one need fuses in the install? Would love to hear the ideas of people here with thoughts and maybe experience with this endeavor.
Regarding the energetics, I think a typical modest freezer draws about 5 amps at 110 volts and runs about half the time. The total energy per day would be about 500 watts x 12 hours, that is, 6 kWh, which is about 10% of the capacity of a long range model 3 battery. So it seems like one could do this for 5 days with a parked car and in that time go from 90% state of charge (SoC) on the traction battery to about 40% SoC. That seems reasonable to me. The current draw on the traction battery is more than an order of magnitude less than freeway driving, so even if it technically voids the warranty, that is not a warranty I expect to use since I keep my battery mostly between 20 and 80% (and I imagine it will outlast the warranty.)) This use would not harm the traction battery in any way I can see. On the other hand, the dc to dc converter (which takes the roughly 360 volts of the traction battery and drops in down to 12 volts) would be working pretty hard. Would the dc-to-dc converter overheat? I have seen some discussion of issues associated with the circuitry around the dc-dc converter and would love to understand that better. Is it designed to or able to handle that sort of semi-continous use? Is there something that limits the current?
So just to summarize: a few questions:
1.Would you do it?
2. How would you do it?
3. Can the dc-to-dc converter and its circuitry handle this?
4. Is the 1500 watt Cantonape a reasonable choice? Is that an appropriate size? Any reason to go bigger? Any reason to go smaller? Any reason to choose pure sine wave or a different type of inverter?
5. Should there be external fuses? How would you install those?
...
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*Cantonape 1500W/3000W(Surge) Car Power Inverter 12V to 110V AC with LCD Display
As I understand it, and I am a fairly new model 3 owner without a long history of Tesla experience, in the model 3 there are two places where one can tap into power. (I am leaving out the 12 V adapter in the console since it is fused way too low). One is in the frunk by connecting directly to the 12 volt battery. The other, I believe, (hoping someone can confirm or dispel this) is under the back seat where there are some power taps? Is this true?
Once a location is chosen, I believe one could connect an inverter that converts 12 volt dc to 110 AC. I don’t think that puts too much load on the traction battery, but it could make the dc to dc converter work pretty hard, and I wonder if that could lead to a failure of the dc-dc converter at some point. I don’t know if the car would have to be “on” for this to work. I am thinking not, since the traction battery will charge the 12 volt battery as needed even when the car is parked and locked. Does this seem like a reasonable choice for the inverter*? Would one need fuses in the install? Would love to hear the ideas of people here with thoughts and maybe experience with this endeavor.
Regarding the energetics, I think a typical modest freezer draws about 5 amps at 110 volts and runs about half the time. The total energy per day would be about 500 watts x 12 hours, that is, 6 kWh, which is about 10% of the capacity of a long range model 3 battery. So it seems like one could do this for 5 days with a parked car and in that time go from 90% state of charge (SoC) on the traction battery to about 40% SoC. That seems reasonable to me. The current draw on the traction battery is more than an order of magnitude less than freeway driving, so even if it technically voids the warranty, that is not a warranty I expect to use since I keep my battery mostly between 20 and 80% (and I imagine it will outlast the warranty.)) This use would not harm the traction battery in any way I can see. On the other hand, the dc to dc converter (which takes the roughly 360 volts of the traction battery and drops in down to 12 volts) would be working pretty hard. Would the dc-to-dc converter overheat? I have seen some discussion of issues associated with the circuitry around the dc-dc converter and would love to understand that better. Is it designed to or able to handle that sort of semi-continous use? Is there something that limits the current?
So just to summarize: a few questions:
1.Would you do it?
2. How would you do it?
3. Can the dc-to-dc converter and its circuitry handle this?
4. Is the 1500 watt Cantonape a reasonable choice? Is that an appropriate size? Any reason to go bigger? Any reason to go smaller? Any reason to choose pure sine wave or a different type of inverter?
5. Should there be external fuses? How would you install those?
...
…
*Cantonape 1500W/3000W(Surge) Car Power Inverter 12V to 110V AC with LCD Display