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Powering the 12v port to run a fridge, can an app keep the Tesla awake?

bradtem

Member
Dec 18, 2018
24
5
Sunnyvale, CA
I am on a Tesla road trip with a 12v camping fridge. It uses about 500wh/day -- about 2 miles of range, but having Sentry mode on to keep the power going uses up 14 miles overnight which is not great. I have seen proposals to use camp mode with heat and AC off as much as possible, or Smart Summon standby, which is disabled in park. Anybody have loss figures for these?

Anyway, I had another idea. Is there an app which will deliberately poll your Tesla every so often to keep it awake? Used to be apps had bad vampire drain from polling too much and they scaled back. But now I want it deliberately. To be very clever, in fact, it could poll just enough to run the fridge for about 20 minutes every hour, which would keep it fine almost anywhere except a hot climate. That would be a cool feature, but until then, does anybody know an app that has "too much" vampire drain because it keeps waking up the car all night? As long as there is data, that would work. Or could a bluetooth app do it in a phone?

Until Tesla implements "fridge mode" that does the 1/3rd duty cycle wakeup or just 12v power all night.

No, I am not going to wire a connector under the seat while on a road trip.
 

GtiMart

Active Member
Nov 13, 2019
1,391
1,222
Quebec City, Canada
If you know how to program, you could use the Tesla API, the same that the Tesla app as well as TeslaFi and others use. You could force a wake of the car when you want, for example to run it "for 20 minutes per hour". What you cannot do is decide when the car falls asleep. It sleeps when it wants... sometimes I grab something from my car, which wakes it up, and it might fall asleep just a couple minutes after. Sometimes it decides it must charge the 12V and stays awake longer. Sometimes I just drove the car and it might spend 30-60 minutes drying the AC radiator. So at best your algorithm could be: it's been more than 40 minutes of sleep, I'll wake it up...
 

bradtem

Member
Dec 18, 2018
24
5
Sunnyvale, CA
If you know how to program, you could use the Tesla API, the same that the Tesla app as well as TeslaFi and others use. You could force a wake of the car when you want, for example to run it "for 20 minutes per hour". What you cannot do is decide when the car falls asleep. It sleeps when it wants... sometimes I grab something from my car, which wakes it up, and it might fall asleep just a couple minutes after. Sometimes it decides it must charge the 12V and stays awake longer. Sometimes I just drove the car and it might spend 30-60 minutes drying the AC radiator. So at best your algorithm could be: it's been more than 40 minutes of sleep, I'll wake it up...
Agreed it may find other reasons to stay awake, though usually in the middle of the night there should not be too many. When I first got the car. Vampire drain was a big issue, but of late it has been more tolerable which means it is keeping wake time under control. I hope they someday find a way to turn on the port without turning on the 250w computer
 

tstolze

Member
Oct 9, 2020
297
432
OFallon, MO
You could connect a power port direct to the 12 v battery just for your fridge... Believe the car would go to sleep, when/if the 12v battery reached the low voltage threshold the contactors would engage to charge the 12 v battery from the main battery.
 
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android04

Member
Apr 1, 2016
483
487
Southeast Nebraska
You can use the Tasker app to easily have it do various things. You can use the Tesla API plugin and make a routine that checks the status of the car every 20 minutes, therefore keeping the car awake.
 

jjrandorin

Moderator, Model 3, Tesla Energy Forums
Nov 28, 2018
10,852
12,578
Riverside Co. CA
You can use the Tasker app to easily have it do various things. You can use the Tesla API plugin and make a routine that checks the status of the car every 20 minutes, therefore keeping the car awake.

That would have the same effect as the person using sentry mode (which requires a lot less work). As @GtiMart said, the power sentry mode uses is from keeping the car awake, so anything that keeps the car awake is going to have the same power drain.

What this OP is actually wanting (which as far as we know, doesnt exist) is a command to put the car to sleep. Any number of things can keep the car awake, but it goes to sleep when it wants to, not when we want it to, not unlike a young child (lol).
 

dc443

Member
May 11, 2021
46
26
Taxachusetts
Pretty sure the best solution to this one is a direct tap on the 12V battery, because any other solution to keep the 12V accessory powered on will power on the car computers which will draw 5x more than your fridge (when it runs…)

If it’s only for the fridge then you’d only need wires that handle a few amps.

I have a fridge as well, and I will have to solve the same problem at some point.
 

bradtem

Member
Dec 18, 2018
24
5
Sunnyvale, CA
Yes. I have found that sentry mode, smart summon standby mode and camp mode will all drain about 2km (1.2 miles) per hour. This is a lot if you are on a road trip outside supercharger country. If you are charging on level 1, you will eat up 25% of the power you were hoping to add a few miles to the car. Include daytime stops and this is quite a lot, so i am using the ice "solution" (the whole point of a fridge is to avoid the many hassles of ice) when I don't plan to charge soon after the night.

I can't rewire the car on the road trip, unless I were to find a store to buy the needed tools and parts, which I did not bring.

However, the teslafi approach has promise.
 

TLLMRRJ

Active Member
Dec 19, 2019
2,034
2,432
Houston
Pretty sure the best solution to this one is a direct tap on the 12V battery, because any other solution to keep the 12V accessory powered on will power on the car computers which will draw 5x more than your fridge (when it runs…)

If it’s only for the fridge then you’d only need wires that handle a few amps.

I have a fridge as well, and I will have to solve the same problem at some point.

Not from what I've read that says directly tapping the battery confuses the charging system.
 
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DaSwede

Member
Jul 8, 2020
51
107
UK
Not from what I've read that says directly tapping the battery confuses the charging system.
I am on a Tesla road trip with a 12v camping fridge. It uses about 500wh/day -- about 2 miles of range, but having Sentry mode on to keep the power going uses up 14 miles overnight which is not great. I have seen proposals to use camp mode with heat and AC off as much as possible, or Smart Summon standby, which is disabled in park. Anybody have loss figures for these?

Anyway, I had another idea. Is there an app which will deliberately poll your Tesla every so often to keep it awake? Used to be apps had bad vampire drain from polling too much and they scaled back. But now I want it deliberately. To be very clever, in fact, it could poll just enough to run the fridge for about 20 minutes every hour, which would keep it fine almost anywhere except a hot climate. That would be a cool feature, but until then, does anybody know an app that has "too much" vampire drain because it keeps waking up the car all night? As long as there is data, that would work. Or could a bluetooth app do it in a phone?

Until Tesla implements "fridge mode" that does the 1/3rd duty cycle wakeup or just 12v power all night.

No, I am not going to wire a connector under the seat while on a road

I am on a Tesla road trip with a 12v camping fridge. It uses about 500wh/day -- about 2 miles of range, but having Sentry mode on to keep the power going uses up 14 miles overnight which is not great. I have seen proposals to use camp mode with heat and AC off as much as possible, or Smart Summon standby, which is disabled in park. Anybody have loss figures for these?

Anyway, I had another idea. Is there an app which will deliberately poll your Tesla every so often to keep it awake? Used to be apps had bad vampire drain from polling too much and they scaled back. But now I want it deliberately. To be very clever, in fact, it could poll just enough to run the fridge for about 20 minutes every hour, which would keep it fine almost anywhere except a hot climate. That would be a cool feature, but until then, does anybody know an app that has "too much" vampire drain because it keeps waking up the car all night? As long as there is data, that would work. Or could a bluetooth app do it in a phone?

Until Tesla implements "fridge mode" that does the 1/3rd duty cycle wakeup or just 12v power all night.

No, I am not going to wire a connector under the seat while on a road trip.
I think it is a bit of madness to start trying to defeat the power system to run a fridge since it would clearly void the warranty of the car as Tesla have said that the car cannot be used as a power supply.

Maybe better to buy a standalone battery to power the fridge rather than trying to create an API to defeat the car going to sleep...
 
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DaSwede

Member
Jul 8, 2020
51
107
UK
I think it is a bit of madness to start trying to defeat the power system to run a fridge since it would clearly void the warranty of the car as Tesla have said that the car cannot be used as a power supply.

Maybe better to buy a standalone battery to power the fridge rather than trying to create an API to defeat the car going to sleep...
Here is the limitation for the warranty (see the bullet at the end):
 

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focher

Active Member
Oct 15, 2013
1,166
1,932
Bay Area
I think it is a bit of madness to start trying to defeat the power system to run a fridge since it would clearly void the warranty of the car as Tesla have said that the car cannot be used as a power supply.

Maybe better to buy a standalone battery to power the fridge rather than trying to create an API to defeat the car going to sleep...
Umm, how would it “void the warranty of the car”? It has to actually break something and that ”something” would be the only warranty claim the manufacturer could deny.

In this case, the risk is to damage the 12V battery. Pretty much every car with a 12V system can support an appropriately sized power inverter attached to it without damage. The only consideration is making sure you don’t overdraw power based on what the battery can supply.
 
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tccartier

Supporting Member
Supporting Member
Oct 27, 2015
989
1,037
AZ.
I am on a Tesla road trip with a 12v camping fridge. It uses about 500wh/day -- about 2 miles of range, but having Sentry mode on to keep the power going uses up 14 miles overnight which is not great. I have seen proposals to use camp mode with heat and AC off as much as possible, or Smart Summon standby, which is disabled in park. Anybody have loss figures for these?

Anyway, I had another idea. Is there an app which will deliberately poll your Tesla every so often to keep it awake? Used to be apps had bad vampire drain from polling too much and they scaled back. But now I want it deliberately. To be very clever, in fact, it could poll just enough to run the fridge for about 20 minutes every hour, which would keep it fine almost anywhere except a hot climate. That would be a cool feature, but until then, does anybody know an app that has "too much" vampire drain because it keeps waking up the car all night? As long as there is data, that would work. Or could a bluetooth app do it in a phone?

Until Tesla implements "fridge mode" that does the 1/3rd duty cycle wakeup or just 12v power all night.

No, I am not going to wire a connector under the seat while on a road trip.

Camping mode? I've never used it but there is an option on my screen for camping mode maybe that would keep accessory power alive.? Just a thought.
 
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DaSwede

Member
Jul 8, 2020
51
107
UK
Umm, how would it “void the warranty of the car”? It has to actually break something and that ”something” would be the only warranty claim the manufacturer could deny.

In this case, the risk is to damage the 12V battery. Pretty much every car with a 12V system can support an appropriately sized power inverter attached to it without damage. The only consideration is making sure you don’t overdraw power based on what the battery can supply.
Well, the additional draw of the 12v battery will require the high voltage battery to kick in and recharge the 12v battery if you have a constant drain due to an added fridge. So, it will indirectly put more pressure on the charging circuit. My thought was that by connecting it to a standalone battery would keep it on the safe side from getting into any warranty breaches.
 

stopcrazypp

Well-Known Member
Dec 8, 2007
10,987
6,099
In any case as I said, whatever api calls you use would just keep the car awake, and that would consume the same thing as sentry afaik. Why not just use sentry?
He obviously doesn't really believe that it consumes the same. If there is an interim mode where the contactor/12V doesn't turn off yet and but the computer is asleep, then that would save power vs Sentry (and similar modes like summon standby. camping, etc). Then you can figure out the interval that maximizes the time the car stays in that mode without turning off the 12V, and just set the trigger to wake the car up on that schedule. Such a mode does not necessarily exist however.

Personally, I don't use Sentry specifically because the power draw is too great for parking long periods of time not plugged in. I instead run other cameras off two 12V 30Ah Lifepo batteries in the storage area under the trunk (used two due to them being on sale for $150 each, plus it gives me flexibility to leave one in the car while the other is charging). In my first iteration, I did have a cigarette socket connector on the cable I routed into the cabin so I can charge the batteries as needed with the car's 12V socket, but I have since removed that and am just charging them out of the car.
LiFePO4 12V 10Ah 20Ah 30Ah 50Ah 100Ah Lithium Iron Phosphate Battery

Two of them gives about 720Wh of capacity. Maybe @bradtem can consider for a next trip (not going to help for this one obviously).
 

cali8484

Member
Jul 8, 2018
282
161
California
Umm, how would it “void the warranty of the car”? It has to actually break something and that ”something” would be the only warranty claim the manufacturer could deny.

In this case, the risk is to damage the 12V battery. Pretty much every car with a 12V system can support an appropriately sized power inverter attached to it without damage. The only consideration is making sure you don’t overdraw power based on what the battery can supply.

It doesn't. Manufacturers can put whatever they want in docs but it doesn't mean it's legal. There is no automatic voiding of warranty legally allowed in the US. Check the Magnuson–Moss Warranty Act. If there is any damage manufacturers must prove it was caused by the add-on/replacement component to deny warranty claim.
 

focher

Active Member
Oct 15, 2013
1,166
1,932
Bay Area
It doesn't. Manufacturers can put whatever they want in docs but it doesn't mean it's legal. There is no automatic voiding of warranty legally allowed in the US. Check the Magnuson–Moss Warranty Act. If there is any damage manufacturers must prove it was caused by the add-on/replacement component to deny warranty claim.
Yeah, that's what I said.
 

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