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Model 3 electric outlet options

Model 3 electric outlet options

I have several needs for 110 outlets in my Model 3. CPAC while camping, electronics like games and monitor for kids on long trips, even running a drill and saw on remote land if I can.

I know nothing about electricity. I have a device that plugs in the cigarette lighter and allows me to have a 110 outlet in my ICE. I have read you can not jumpstart an ICE because the Tesla has a small 12 volt battery that is recharged by the main batteries. Here is my question:

Will I be able to power the following from my Model 3 and if so, how?

CPAC
CAMPING FRIDGE
Small monitor and game system
Recharge electric drill
Run 110 outlet saw

I have a solar powered generator. A solar panel, battery, and electronics. My go to answer is to disconnect the solar charger (or keep it in trunk if I have space), use the Model 3 lighter plug to charge this system and then use it for 110 power.

Sof | December 24, 2017

Here is the info from the owners manual:

12V Power Socket
Your Model 3 has a power socket located in
the rear compartment of the center console.
Power is available whenever the touchscreen
is powered on.

The power socket is suitable for accessories
requiring up to 12A continuous draw (16A
peak).

Warning: The power socket and an
accessory’s connector can become hot

rxlawdude | December 24, 2017

It's likely the 12V plug device you use doesn't draw more than 12A, which means it will work in the M3. But reading your list of items, it seems that's a helluva lot of power potentially consumed. You can get about 110W of AC (figuring some loss from the inverter), so consider that.

As to what to do when camping to avoid killing the 12V battery, others have discussed ways to allow the car to remain "on" in what is affectionately called "camping mode" that runs the lights, infotainment, and AC. The 12V plug would be active in that mode.

prsist | December 24, 2017

Go buy yourself a small Honda generator for your camping needs. The Model 3 is a car, not a power source. That being said, if it works, it works....if it doesn't, it doesn't. Geez that's profound...LOL

Kathy Applebaum | December 24, 2017

Second the idea of buying the generator. Converting the 12v-12A outlet to 110 gives you 1.3A, which isn't going to power much. By contrast, the smallest generator Home Depot has gives you 30A on 110 -- you could even use it to charge your car if you needed to.

Fishe | December 24, 2017

Gas generators are noisy and you have to bring gasoline in your car. This is really a bad choice. The new mitsubishi phev has an inverter built to handle your high amperage 110v needs, a good choice for electric vehicles of the future.

I Wanna Go Fast | December 25, 2017

Quieter than the saw and maybe the drill I'd guess... but seriously not sure where you'd be going that wouldn't have 110V. Not far from home obviously, as running all of this will soon drain your HV battery.

Frank99 | December 25, 2017

I'm not sure about "running all of this will soon drain your HV battery" - The Tesla batteries have an amazing amount of power.
My home A/C (to cool a 2500 sq. ft house in Phoenix) takes 10KW - a Tesla could power it for 6 hours.
A circular saw takes about 1.5 KW, so a Tesla would power it for 40 hours.
A PS4 takes about 0.15 kw, and a small monitor about 0.03 kw; a Tesla could power them for 300 hours.
A camping fridge (compressor style) might take about 0.010 kw; a Tesla could power it for 5000 hours.

I don't know how much power the onboard 12V battery charger can supply; but I'd guess that anything smaller than 240W (20A @ 12V) could be powered continuously; it's possible the car has a larger charger, but I find it unlikely that you could draw 1000 W (8A @ 120V, 80A @ 12V) without draining the battery i.e. the onboard charger is likely smaller than 1000W.

Garyeop | December 25, 2017

@I want to go fast
In the KC area you can drive 1 hour out of town to areas that are the same as they were 100 years ago minus the buffalo plus the chip rock roads.

@Frank99. Thank you for understanding. I will never take a gas generator camping. A solar generator gives enough power to develop a camp shed on wilderness land. I want to make a shower, a tent platform, and perhaps an outhouse.

Point being we will be driving a giant battery pack. It would be nice to have options other than driving in making use of it. Like power backup during the zombie apocalypse. What can I say, I like options without being MacGyver.

Mr.Tesla | December 25, 2017

Propane generators are the best. Those tanks won't leave any fumes or spills, and the propane doesn't go bad, like a can of gasoline would. Plus, propane burns much cleaner than gasoline.

jefjes | December 25, 2017

How about using additional 12v batteries that you've pre-charged at home? You may even be able to hook them up parallel in the frunk and connect them to the 12v charging system for the car's 12v battery to charge/keep charged on the way to the location you plan to use them. Depending on the size, they may last for awhile using an inverter but depending on the inverter load/size, I would disconnect them from the car during use to avoid any problems.

stevea137 | December 25, 2017

By the sounds of it, the DC-DC converter in the Tesla is quite limited (12A continuous at 12v is only 144W) and is really only meant to recharge the 12v battery and not a lot else. It could probably run one of those devices from your list at a time, minus the AC saw (or the CPAC, no idea what that is. Did you mean CPAP? it would likely run that no problem).

About the best you could do is use the Tesla to slowly charge your solar system on cloudy days, assuming you can limit its draw to less than 140W. Or keep the solar system's battery topped up during the night.

In simpler terms, think of your Tesla as providing about as much power as the solar panel in your solar generator system and then use it accordingly.

I Wanna Go Fast | December 26, 2017

@garyeop, why would you want to go there :P

@Frank99, I understand the numbers, but you can lose 200mi range overnight with the cabin heater on to keep you warm while you play the PlayStation. To continuously draw 12V power means to continuously have the high voltage system fully energized and consuming energy to support. The lower the device current, the more wasteful the vehicle architecture is when parked idle.

Rocky_H | December 26, 2017

@stevea137, Quote: "By the sounds of it, the DC-DC converter in the Tesla is quite limited (12A continuous at 12v is only 144W) and is really only meant to recharge the 12v battery and not a lot else."

I don't think it's that. It's the fuse in the path to where you can access it from the 12V socket. That generally uses a 10A fuse. So drawing the most you can through that, and using an inverter to switch it to AC makes 12V 10A into 120V 1A. That is just not much energy to power 120V style devices. Sure, electronics like a laptop or something will do fine, but larger stuff is going to pull more than 1A.

Regarding the Mitsubishi Outlander having it, yes, I think it's a feature that some people want, and it's kind of useful, and it is a little weakness that Tesla doesn't have it. But not every car has every single feature people want.

giskard | December 26, 2017

I would have been interested in this as well as I plan to use my Model 3 as an occasional "camper" (the only thing I don't like about camping is trying to sleep in the heat). I have a portable camp fridge/freezer that I do plan on running off of the 12v socket, too. It would have been nice if Tesla included a 12v socket in the trunk are - as it is I'll probably have to get an extension of some sort up to the center console.

Who knows, maybe the aftermarket will come through. It will depend on whether or not they think there's a market and how difficult it is to get access to more power from the main battery.

Coastal Cruiser. | December 26, 2017

There's a lot of good suggestions here. Picking up on one of them, I think the DYI approach I personally would investigate if I needed a good supply of either 12v DC or 120v AC would be to construct a frame that would fit in the Frunk and be populated with a few 12v Optima BLUE TOP maintenance free batteries. The auxiliary batteries would be wired in PARALLEL.

Then there are TWO ways to use the battery pack.

1) The easiest and most surefire way would be to simply connect one or more 12v outlets, or a beefy inverter, to the positive/negative terminals on the aux batteries. That's it. No connection to the car.

2) The other way would be to connect the aux batteries to the car via the port on the Model 3 for jumping a dead 12v onboard battery. This would require making up a wiring harness that would plug from the batteries to the jump port. The idea here is that you would simply be augmenting the onboard battery with additional run-time. This might be the least intrusive solution in terms of connecting to the car.

The advantage of the latter solution is two-fold; You could use the onboard 12v "cigarette" outlet, and it would simply have much greater run time. Secondly, you _might_ be able to charge the aux batteries when the car is operating. That would pave the way for multi-day road trips. It's probably a warranty killer, but may be technically possible. The aux batteries would simply charge as the car charged the native 12v battery (slower of course).

One caveat for the charging aux battery scenario: You would want to buy the same type of 12v battery used in the Model 3... flooded lead acid, AGM, or Gel Cell (I don't know which type Tesla is using). Each type of battery uses a different charging voltage and the Model 3 12v charger will be tuned for one of those three types.

I would want to learn more about that jump port as well... a) Is it a two-way connection? Will it feed power OUT as well as in. b) What is the current carrying capacity of the wires connecting the port to the battery? Probably not an issue, but you would then know what size fuse to use on your wiring harness that plugs into the port. (safety first).

Gotta love that Frunk!

Daryl | December 26, 2017

I bought an after-market kit for my Volt that includes a 2000 W (3000 peak) inverter that could power my refrigerator in an emergency. I've never had to use it, though I've tried it out to make sure it works.

stevea137 | December 26, 2017

@Rocky_H et al, an important difference to keep in my is the difference in ICE vs Tesla 12V supply.

An ICE 12V battery can supply stupid amount of amperage (think hundreds of amps), mainly to power the starter in short bursts. The alternator in the average ICE vehicle itself can provide 100 amps continuous, and upgrades to 200+ amps are not uncommon. In these cases the 10A fuse to the cigarette lighter is to protect the wiring and socket (which was never designed for high amperage continuous draw).

The Telsa is different however. The 12V battery is just there to power auxiliary low voltage DC systems. The most current demanding of these is probably the window motors. Also, there is no 100+amp alternators for recharging. There is just a DC-to-DC converter. These are not cheap or simple little devices, especially when you are stepping down to 12V from 400V. And they also run at peak efficiency when running at near peak output. So, for example, designing in a spare 50A of capacity that most people would never tap into would reduce overall efficiency by some percentage.

But in the end I am just guessing based on informal EE training and from the "12A continuous, 16A peak" rating on the 12V socket. I'm not going to push it to see what melts first, the 12V socket, fuse, or DC-DC converter ;)

johnmann | December 26, 2017

Maybe you could use a generator powered by the Teslas drive wheels. Like the generators that some bicycles use to power a light. I’ve seen these used at backcountry construction sites powered by a truck with one wheel jacked up and placed on the generator’s rollers. I’m not sure whether they are a commercial product or a homemade horror violating nearly every known safety regulation.

Coastal Cruiser. | December 26, 2017

stevea137, apologies, but I'm not sure that comment adds to the conversation. Most people likely understand the 12v battery in a Tesla is not designed for the rigors of starting an ICEmobile.

Keep in mind the that the purpose of the DC-DC converter is only to charge the battery. It _converts_ ~400v of the battery pack down to a voltage just above 12v in order to charge the 12v battery. It is likely NOT used to power the "cigarette" outlet. There is no need because it is a 12v to 12v connection. That style of outlet is only rated for so much current, and the fuse does as you stated; it protects the socket and the wiring.

If you have specific knowledge that the Model 3 uses the DC-DC converter to power the 12v outlet then please state such and I will withdraw my objection to your comment. ;>

stevea137 | December 26, 2017

No worries @Coastal_Cruiser, just a conversation about what we could get away with powering off the 12V socket (i.e. could you power a camping fridge off it?).

So charging the 12V battery in the Tesla works like it does in any ICE vehicle. When the vehicle is off, the battery is the power source and provides power for the entire 12V sub-system including 12V sockets. When the vehicle is running, the alternator (ICE) or DC-DC converter (tesla) is providing the power for the entire 12V sub-system. In effect, the 12V battery becomes a drain while the car is on because is it charging. If a large load is put on the system, the battery and DC-DC converter can both provide power to meet the demand until the battery is discharged too far, then the load falls entirely onto the DC-DC converter.

Given the engineering I have seen on some tesla tear downs, I would assume there are breakers or resettable fuses to protect the DC-DC converter rather than letting burn out.

casun | December 26, 2017

who doesn’t have a solar powered generator?

Rutrow | December 26, 2017

FYI. From the owners manual, page 106:

"Caution: Do not use the Battery as a stationary power source. Doing so voids the warranty"

:-O

Coastal Cruiser. | December 26, 2017

Thank you Mr. Rutrow. I nominate you the official "when all else fails read the manual" officer. :>

stevea137 said: "...When the vehicle is running, the alternator (ICE) or DC-DC converter (tesla) is providing the power for the entire 12V sub-system."

Actually you got me interested in the specifics of how this works and I was looking up some info on the Tesla 12v battery. We are down to the "devil is in the details" level, but as you may agree this is a necessary level if one is to really understand what the hell is going on.

I found a few Model S forum threads on the battery. The Model 3 may or may not follow this. One member asserted that the car's electronics are _always_ powered by the 12v battery. When the 12v battery reaches 50% discharge the contactors to the main battery close and the converter simply charges the 12v battery. So that may be exactly what you said, in that a certain amount of current from the main battery finds it way to powering the 12v load, with the 12v battery acting as a buffer. Not too different from an ICEmobile, with the exception that the Tesla 12v battery may drop to a lower voltage before the converter is activated.

RETURNING TO THE OP, given what Rutrow said, i think an external solution to run CPAP machines and the like will need a totally external solution, like one of those portable power units you see for sale that contain a battery and inverter. Only wacko DYI types may attempt the other solution I suggested.

It will be interesting to see if someone finds a nice beefy external power supply that tucks nicely into either the Frunk or the compartment below the trunk. The latter may be the more workable solution in that you could more easily route the power cable to the equipment inside the car.

Coastal Cruiser. | December 26, 2017

Here is an example of an external power unit on ebay:

ebay
.com/itm/Poweradd-Power-Inverter-100W-12V-dc-to-110V-120V-ac-car-RV-50000mAh-Generator-/282405423230?_trksid=p2385738.m4383.l4275.c10

It puts out 5 amps at 110VAC. It also appears that you could charge it off the car's 12v power socket during the day while the car is in operation.

The seller did not include the dimensions, but the unit looks pretty tiny. may well fit in the frunk/trunk well.

Just an example....

stevea137 | December 26, 2017

lol, nice find @Rutrow. When all else fails, RTFM.

Interesting info @Coastal_Cruiser, you just blew my mind. I dug around also and indeed Tesla is letting the 12V battery discharge to 50% SOC while the car is off before recharging it. Even with a deep cycle lead acid battery, that is nearly abusive to the battery. Hopefully they have addressed this somehow in the M3, cause I don't feel like having the 12V battery replaced every 12-18 months!

Back to OP, on top of what @Rutrow stated from the manual, DO NOT use your Tesla as a power source unless you like replacing it's 12V battery very often!

Coastal Cruiser. | December 26, 2017

I came across several threads of Model S owners getting the blues for having to replace the 12v battery fairly regularly.

In another thread a guy did a fairly deep analysis of why the failure rate was so high. He came to the conclusion that the 12v battery was cycling a LOT, may not be getting charged fully, and of course we have just learned about the 50% discharge before being recharged.

That last one of course is maybe due to a balancing act to keep the main battery from over discharging, but when you add it all up it doesn't take a rocket scientist to understand why the 12v battery failures were/are so high.

Coastal Cruiser. | December 26, 2017

here is the link to the guy who troubleshooted the battery issue...

syonyk.blogspot
.com/2016/10/tesla-model-s-12v-battery-analysis.html

stevea137 | December 27, 2017

Thanks for the link, interesting read. Almost makes me wonder if the had the Lithium flunky work on the 12V charging scheme...

giskard | December 27, 2017

Very interesting discussion on something I hadn't considered too much. Hopefully Tesla has come up with a better strategy for the Model 3 to make the 12v battery last longer. However, if they haven't, does anyone know what kind of battery it is and how difficult it is to get to? In other words, could I run to an auto store (or Walmart), pick up a new battery, and install it without having to disassemble part of the car? I'm sure the Tesla rangers will be up to the task but I would prefer to not have to rely on them for something that might be relatively common (especially given how far I am from the nearest Tesla service center).

johnmann | December 27, 2017

I've heard of other electric cars having this problem, including ours. We've had to replace the 12 volt battery in our 6 year old Leaf twice. I wonder whether lead-acid batteries are just not well suited to the application or if they haven't quite figured out the best charging schedule for them yet. Maybe a 12 volt lithium battery might be a better choice.

Also I don't quite understand the references above to the recharging not starting until the battery reaches the 50% discharge point. If the battery has a nominal voltage of around 13.5 volts does that mean it doesn't start recharging until it gets down to 6.75 volts. Hardly likely. I'm assuming that it means that charging will start when it gets down to 12.75, halfway between 12 and 13.5.

Coastal Cruiser. | December 27, 2017

giskard, In a forum topic on the Model S battery (which I can't find right now) there was discussion about self replacement of the 12v battery. consensus was that it is possible to change it yourself, although if under warranty you must have Tesla do it.

As far as the Model 3 goes, probably by the time anyone needs to change the 12v battery we will know a lot more. I saw a reference months ago that the battery was in an easier to reach location than the S. Also, I don't know if they are still using lead-acid or not.

johnmann, the link I posted earlier addresses your question as to why the batteries are failing sooner than one would expect. Although Tesla (at least in the Model S) uses a "deep cycle" battery, which is designed to cycle far more often than say a conventional starting battery, it none the less is limited in how many cycles it can tolerate over its life, and the application in the Model S seems to cycle the battery a lot.

Although most people discussing the topic of getting away from a lead-acid battery suggest switching to Lithium-ion chemistry, a better choice may be Nickel Metal Hydride. That's the chemistry used in most hybrids to power the car down the road. Nickel Metal Hydride is not as energy dense as lithium-ion, but it is tolerant to a wider array of temperatures. Having said that, Tesla likely had a good reason to use lead-acid in the Model S. Again, I have not seen confirmation of what is used in the 3. Keep in mind that per Elon, the 12v battery may go away in the next generation of vehicle they produce.

Regarding the 50% discharge, your latter assumption is correct I believe. However, taking a lead -acid battery down to 50% of charge (say 12volts), greatly reduces the life of the battery. In solar applications the consensus is to never take the batteries down more then about 30%.

https://www.teslarati.com/understanding-tesla-12v-battery-service-warning/
https://forums.tesla.com/forum/forums/12v-questions

giskard | December 27, 2017

Good to know - thanks for the info (I don't hang out in the Model S forums). As you said we should know a lot more by the time this might be an issue for us.

SUN 2 DRV | December 27, 2017

This all underscores why people who drive a lot have to replace their 12v batteries less often than the drives with lighter usage.

Driving replenishes the 12V battery before it get's deeply discharged, and during driving the HV DC-DC converter handles all the 12V loads and thus the 12V battery is less taxed than if the car was off and just sitting, because the 12V battery has to power all the 12V systems by itself.

I drive my MS 1.5-2 hours twice a day and have only had to replace my 12V battery once in 102k miles. Other MS owners have had to change it at much shorter intervals.

johnmann | December 27, 2017

Thanks for redirecting me to Syonyk's battery page again, Coastal_Cruiser. I had seen it in your earlier post, but didn't have time to read it and then forgot about it. I now see the problem that Tesla and others face in keeping the battery healthy. Since the vampire drain is so high the battery has to be topped off frequently. It would be best if the car could keep it in a float state instead of cycling it. The way the DC-DC converter currently works requires that the car be turned on, or "energized" for lack of a better word, so it isn't practical to do that. Maybe there could be a way to have a 12 volt tap on the traction battery that could maintain the 12 volt battery. This wouldn't require any voltage conversion and would be much simpler than the DC-DC conversion. The problem is that the cells would become out of balance, but the car could re-balance them when it was turned on again. Maybe the cells used for the 12 volt tap could rotate so that the same ones weren't always being used. At the very least, as pointed out on Syonyk's page, they shouldn't be cycling it while the car is plugged in. Then it would only be a problem when the car is sitting idle and not plugged in. It would be yet another reason why a plugged in Tesla is a happy Tesla.

Frank99 | December 27, 2017

I'm hoping that the 12V subsystem has been redesigned for the Model 3. My understanding is that it still has a lead-acid battery, but hopefully some of the improvements suggested by others in this thread have been implemented.

I'd also like to see a change in chemistry - NiCd, NiMh or LiFePO4 might be really good. Here's a link comparing lead-acid and LiFePO4:
http://www.pse.nl/media/datasheet/lithium-ferro-phosphate-batteries-vs-v...
Newer LiFePO4 chemistries are up to 5000 cycles...

Frank99 | December 27, 2017

Actually, what would solve the problem almost 99% would be a change in computer system design. If my phone can do everything that it does for two days on a 10 w-hr battery, imagine how long it would last on a 720 w-hr lead-acid or small 100 w-hr LiFePO4 battery?

After all, what does the car computer need to do when it's not running the car/charging?
- Listen for the key fob/Phone Bluetooth to come in rage (My phone does the same thing)
- Measure cabin/battery/exterior temperature. This takes 0 power on any rational measurement scheme, and If the temp requires turning on the heater/AC, then the contactors have to close and the battery can be charged.
- Listen for commands over LTE for downloading logs/updating FW. My phone does this as it's primary purpose.
- Retain the main computer state so that when the owner shows up, the car is immediately ready to go. This must be the main source of current draw when the car is off - but should also be able to be handled easily using techniques similar to current laptops/tablets.

And that's about it. The car should be able to sit for weeks without needing to charge the 12V battery, and yet still be immediately ready to go when the owner shows up. And by implementing things like not cycling the 12V battery when power is connected or the car is running, Tesla should be able to extend battery life to multiple years.

And, yes, I'm an engineer, and customers hate it that our product takes 50 microamps rather than the 10 microamps that they'd prefer while measuring temperature and sensing the user to determine when to perform it's main function.

Frank99 | December 27, 2017

"to come in RANGE".

Coastal Cruiser. | December 27, 2017

I think those following this thread will now be well equipped to understand why the Model Y (or some future model) will come sans the 12V battery. Without taking the time to look it up (chance for error), I do recall that at the same Musk stated he wanted to dump the 12v battery, he also talked about greatly reducing the wiring harness.

It will be interesting to see how that all works out. Will we have 400 volt accessories, such as 400v headlamps? Or will we have a series of DC-DC converters scattered about the car?

Ooooooooooooor ... does anyone remember what Elon said he was studying as an energy solution for electric cars before he locked on to Lithium-ion cells? CAPACITORS. It's been several years since he abandoned that notion. One has to wonder whether the latest capacitor tech could maybe pull of keeping things running while the main battery is asleep....

Inquiring minds want to know.

Carl Thompson | December 27, 2017

@Coastal_Cruiser:
"I came across several threads of Model S owners getting the blues for having to replace the 12v battery fairly regularly. In another thread a guy did a fairly deep analysis of why the failure rate was so high. He came to the conclusion that the 12v battery was cycling a LOT, may not be getting charged fully, and of course we have just learned about the 50% discharge before being recharged."

It's definitely not just Teslas. In my previous Coda EV and my current BMW i3 I've averaged maybe 18 months before needing to replace the 12V battery. My Volt did not need a new battery in the 3 years I had it so maybe GM is doing something different with it.

@SUN 2 DRV:
"This all underscores why people who drive a lot have to replace their 12v batteries less often than the drives with lighter usage. Driving replenishes the 12V battery before it get's deeply discharged ..."

I don't think this is true. These cars don't have alternators so I'm not sure that driving makes any difference in how much or how often the 12V is discharged. And I've driven my EVs plenty (60 mile round-trip every day) so that didn't seem to prolong my 12V battery life (but those EVs weren't Teslas).

stevea137 | December 27, 2017

I think given how often the 12V battery is cycled a day (calculated to 6 or more times a day) driving it an hour a day twice day is likely only going to save it a cycle or two a day. Not a lot in the long run, but the float charging while the car is on may help desulfinate the battery, which would help extend the battery.

I think the extra killer in addition to the frequent cycling is the odd 15.8V pulses noted in that one analysis. There is really no reason to do that to an AGM, nor is an AGM going to tolerate that long before it gases off all the electrolyte.

The reason they wen't for lead acid is it is extremely stable and abuse tolerant over a wide range of temperatures. It will resist freezing down to almost -90F when charged and can be float charged with no ill effect. NiMh would be the next best choice, but those aren't easy or cheap to get off the shelf(and might still require a heater). And Li Ion and LiFePO4 aren't nearly as abuse or temperature tolerant.

Even if they would have limited the depth of discharge to 60%, it would have greatly increased battery lifespan. A more conservative 75% or slightly larger battery would get years of lifespan. Strange weak point in the Tesla design.

Rocky_H | December 27, 2017

@Carl Thompson, Quote: "I don't think this is true."

Yes, it absolutely is true. It has been monitored and measured, and the data confirms it. That is what reduces the number of and depth of discharge cycles of the 12V battery.

Quote: "These cars don't have alternators so I'm not sure that driving makes any difference in how much or how often the 12V is discharged."

That's like arguing whether it's called hay or straw. They're the same thing. When the car is on, the DC to DC voltage converter circuit is running, keeping the 12V battery topped up and not draining. It is serving exactly the same function as an alternator. The more frequently the car is on, the more it has that maintenance charge and the less amount of downtime there is for the 12V battery to keep getting drained down low enough where it has to get refilled again.

Carl Thompson | December 27, 2017

@Rocky_H:
"When the car is on, the DC to DC voltage converter circuit is running, keeping the 12V battery topped up and not draining."

Ah, I didn't realize it worked like that. I thought the DC to DC converter came on when needed regardless of whether the car was being driven or not.

At any rate in my experience (with other EVs) driving didn't help battery longevity. I drive about 3 hours every day and I still have needed to replace the 12V battery in my EVs about every 18 months or so.

msmith55 | December 27, 2017

I think someone makes a Li-iron replacement 12 V battery for Tesla cars, perhaps you should look at using that if you're going to use a lot of 12 V power. Then you don't have to worry a out frequent discharges to 50 percent.

msmith55 | December 27, 2017

Element3batteries.com. $439 each.

stevea137 | December 28, 2017

Interesting product, but I wouldn't put that in a Tesla which is still under warranty.

Also would not use that replacement if you live anywhere where it drops below freezing on a regular basis. Charging lithium batteries (LiFePO4 included) below 32F/0C can cause major irreversible damage in a single charge.

greggwon | July 8, 2018

I understand from a post about installing a dash camera, that the 12v battery is accessible via a firewall grommet/passthrough in the top left corner of the passenger side foot area. If this pans out, it should be possible to install larger wires to a larger inverter to get above 10amps out of the battery, or another larger capacity 12v source outside of the car. PowerPoll connectors on a feed line form the battery would allow you to switch the source to a larger 12v power distribution system. The battery type installed in the model 3 appears to be similar to the aux battery in the Prius. I have a 400watt inverter in my prius connected with #10 wire running from the front of my prius to the aux battery in the rear. Any place you run high amperage source wiring requires adequately sized fuses on both ends to avoid wire heating that could create a fire.

Elon has posted that there will be a 240v inverter system available in the new pickup truck for working in the field, all day, without worries. They are making progress on improving battery storage and charging speed based on what I see, so it would seem probable that the pickup would be more readily usable in this kind of environment.

jslloyd9 | October 1, 2018

Old thread, I know. OP wanted 110V electricity while camping / boonies. My suggestion is one of the better LiOn storage batteries from GoalZero or Inergy. IMO, the best of the lot is the Inergy Kodiak line. Not cheap, $1500 (street price) and up. GoalZero Sherpa 100AC at the low end (storage-wise) is a really nice product at $300. Their Yeti line of larger units are also really nice units. My local Costco carries the Yeti 1000 for, you guessed it, $1000.

Iwantmy3 | October 1, 2018

I picked up one of these.
https://www.amazon.ca/gp/product/B019PSB6YG/ref=oh_aui_detailpage_o08_s0...
It is useful in powering a laptop or other items with limited power needs.

gabrielfair | December 30, 2018

I got some updates on this. You can pull 180watts. What would be best is to find a way to not have to convert to AC but to use your devices with a DC->DC converter.

"the main battery DC to 12V DC inverter (to charge the 12V battery) is fused for 250 amps"
https://forums.tesla.com/forum/forums/specification-dcdc-converter-tesla...

"the 12 v “cigarette lighter” power connector is fused for 15 amps"
http://teslatap.com/undocumented/

gballant4570 | December 30, 2018

I used to go camping. I used to go backpacking. It was all very enjoyable, resulting in unforgettable experiences. Now I stay in hotels. All I want is destination charging at hotels and vacation rentals. I can already charge my cell phone in my Tesla....

In other words, a 110v power outlet isn't an interest for many Tesla owners/prospective customers.

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