Fair point. I made sure the inverter ground was not connected to the negative. I was worried about the DC-DC positive shorting to the chassis anywhere, so I connected it directly to the inverter and taped it carefully
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How many amps can you get from the 12V system for emergency situations?
- Thread starter marcmerlin
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n2mb_racing
Active Member
Fair point. I made sure the inverter ground was not connected to the negative. I was worried about the DC-DC positive shorting to the chassis anywhere, so I connected it directly to the inverter and taped it carefully
Good reasoning. I don't know if mine is isolated from the case. I'd have to check...
Slightly off topic, sorry guys, I'm may be getting a ledbar highbeam on my model 3.
Its pulling 126 watts ( 8.8 amps at 14.4volts ) .
Would the DC-DC battery charger be able to keep up with this load while the car is "running" ? or will it slowly discharge the 12v battery ?
Obviously it wouldn't be on constantly but just thinking worst case.
Its pulling 126 watts ( 8.8 amps at 14.4volts ) .
Would the DC-DC battery charger be able to keep up with this load while the car is "running" ? or will it slowly discharge the 12v battery ?
Obviously it wouldn't be on constantly but just thinking worst case.
My guess is that you should be fine. I'm pretty sure there is some circuit between the DC-DC bar and the standby battery and therefore you can't just pull a bunch of amps, but 8A should be fine while the car is awake.
The car will tell you if the standby 12V battery is dipping too low (although if that happens you need to do a full reset by unplugging it and plugging it back in, as the car assumes the only way this happened is that your battery became bad).
The car will tell you if the standby 12V battery is dipping too low (although if that happens you need to do a full reset by unplugging it and plugging it back in, as the car assumes the only way this happened is that your battery became bad).
n2mb_racing
Active Member
That's fine, just don't connect it to the battery directly. Use one of the other 12V circuits. Someone suggested the subwoofer amp circuit is rated for 30A.
That is a very bright light! Where are you going to mount it? And why?
n2mb_racing
Active Member
Supposedly on the model 3 the 12V battery charging current is only 6A, so pulling 8A is probably not a good idea.
Yeah, I couldn't find good info on that. However my main concern is you'd be constantly discharging the battery while the car is running and it'd be constantly trying to charge it. As long as the charging system stays on all the time, current should pass through and you should be fine.
But there is potential for things not lining up somehow.
If you cannot find 12V power coming from the main DC system (switched power) in the frunk, then try it, monitor the battery voltage and see if it works. Worst case, you could damage your frunk battery and have to replace it.
Trying to biump this one a bit
Anyone knows of a switched 12v source in the frunk area so I can connect my powerhungry (120w) ledbar to without having to fish a wire in to the cabin?
I would need about 8-10 amps depending on voltage
I want to avoid connecting directly to the 12v battery to avoid draining it and possible get an error code thrown at me
Anyone knows of a switched 12v source in the frunk area so I can connect my powerhungry (120w) ledbar to without having to fish a wire in to the cabin?
I would need about 8-10 amps depending on voltage
I want to avoid connecting directly to the 12v battery to avoid draining it and possible get an error code thrown at me
You should fish a wire from inside the cabin and connect to the electrical system properly as shown below.Trying to biump this one a bit
Anyone knows of a switched 12v source in the frunk area so I can connect my powerhungry (120w) ledbar to without having to fish a wire in to the cabin?
I would need about 8-10 amps depending on voltage
I want to avoid connecting directly to the 12v battery to avoid draining it and possible get an error code thrown at me
Thanks, I've seen that one. Just wish there was somewhere in the frunk area to use so I don't have to fish
With the change to the electrical architecture from Model S to Model 3, there is much less electrical stuff in the Model 3 frunk area.Thanks, I've seen that one. Just wish there was somewhere in the frunk area to use so I don't have to fish
I appreciate all the information on this thread; special thanks to marcmerlin. Hopefully my experience could be helpful to some. I built the exact circuit marcmerlin described in his blog, but it didn't work for my specific inverter (see below for components). It occurred to me that the basic concept of this type of inrush limiter circuit is probably very specific to the type of inverter. My inverter has an electronic switch and a remote and would never achieve an appropriate voltage to trip the 12v relay. So, I created a new type of inrush limiter circuit that works with my inverter and should work with every inverter.
The basic concept is a larger relay that delivers approximately 4-5 amps (voltage variance) to the inverter during a time delay period. After the delay, 10 seconds in my setup, the timer relay closes the main 12v relay. The timer relay automatically starts when it detects voltage; so when the DCDC converter turns on.
Here is the basic info:
Components:
GIANDEL 2200W Pure Sine Wave Power Inverter - https://amzn.to/37z5FG2
UCTRONICS DC 12V Time Delay Relay - https://amzn.to/36C9Amf
Cutequeen 2PCS 100W Watt 3 Ohm Resistor - https://amzn.to/39BDLMk
ZOOKOTO 150 Amp Circuit Breaker - https://amzn.to/37wreqS
Notes:
- I wouldn't recommend the circuit breaker. It trips at around 60A under load.
- I used 14 gauge AWG wire
Let me know if any other info would be helpful.
The basic concept is a larger relay that delivers approximately 4-5 amps (voltage variance) to the inverter during a time delay period. After the delay, 10 seconds in my setup, the timer relay closes the main 12v relay. The timer relay automatically starts when it detects voltage; so when the DCDC converter turns on.
Here is the basic info:
Components:
GIANDEL 2200W Pure Sine Wave Power Inverter - https://amzn.to/37z5FG2
UCTRONICS DC 12V Time Delay Relay - https://amzn.to/36C9Amf
Cutequeen 2PCS 100W Watt 3 Ohm Resistor - https://amzn.to/39BDLMk
ZOOKOTO 150 Amp Circuit Breaker - https://amzn.to/37wreqS
Notes:
- I wouldn't recommend the circuit breaker. It trips at around 60A under load.
- I used 14 gauge AWG wire
Let me know if any other info would be helpful.
I appreciate all the information on this thread; special thanks to marcmerlin. Hopefully my experience could be helpful to some. I built the exact circuit marcmerlin described in his blog, but it didn't work for my specific inverter (see below for components). It occurred to me that the basic concept of this type of inrush limiter circuit is probably very specific to the type of inverter. My inverter has an electronic switch and a remote and would never achieve an appropriate voltage to trip the 12v relay. So, I created a new type of inrush limiter circuit that works with my inverter and should work with every inverter.
The basic concept is a larger relay that delivers approximately 4-5 amps (voltage variance) to the inverter during a time delay period. After the delay, 10 seconds in my setup, the timer relay closes the main 12v relay. The timer relay automatically starts when it detects voltage; so when the DCDC converter turns on.
Here is the basic info:
Components:
GIANDEL 2200W Pure Sine Wave Power Inverter - https://amzn.to/37z5FG2
UCTRONICS DC 12V Time Delay Relay - https://amzn.to/36C9Amf
Cutequeen 2PCS 100W Watt 3 Ohm Resistor - https://amzn.to/39BDLMk
ZOOKOTO 150 Amp Circuit Breaker - https://amzn.to/37wreqS
Notes:
- I wouldn't recommend the circuit breaker. It trips at around 60A under load.
- I used 14 gauge AWG wire
Let me know if any other info would be helpful.
I did almost the same thing - although essentially manually. Momentary on switch passes through a current limiting resistor to charge the inverter and after that activate the relay and release the momentary on switch.
I meant to say the basic concept is that a larger resistor, with less resistance (3 ohms), delivers approximately 4-5 amps (voltage variance) to the inverter during a time delay period.
TimothyHW3
Active Member
According to the manual from October(it is the 2020 model 3 or up manual, because it doesn't have the auto trunk in the manual) it should get 12A continuously and 16A peak. Maybe they upgraded.
JCtx
Member
To revisit the original title, the 12V socket is good for 12A then? I need to check my little compressor, but I think it should be good with 10A, but 12A would be safer, to prevent the breaker from tripping (there're no fuses on our cars, right?). By the way, the 12V battery is a 51R, which it not a motorcycle battery, but probably the smallest car battery I've seen. And it's not AGM, which can also be confirmed by Tesla's price of $85 . Oh, and we shouldn't attach anything directly to the battery, correct?
Finally, I couldn't snap back the clips on the battery cover next to the frunk opening. The whole thing is so flimsy I was afraid to break something, so left them unsnapped. The side ones and upper ones did snap, so that's enough, but not amused by the build quality. Had a snap missing, so next time I remove the thing will relocate one of the useless ones to the right side.
. Oh, and we shouldn't attach anything directly to the battery, correct?Finally, I couldn't snap back the clips on the battery cover next to the frunk opening. The whole thing is so flimsy I was afraid to break something, so left them unsnapped. The side ones and upper ones did snap, so that's enough, but not amused by the build quality. Had a snap missing, so next time I remove the thing will relocate one of the useless ones to the right side.
So based on this one could safely tap 10amps for a ledbar continously from the posts on the 12volt battery ?
Do you have a link or screenshot from this manual ?
TimothyHW3
Active Member
Just Google Tesla Model 3 manual and search in the PDF for 12 or 16.
But it could be for the 12V outlet only.
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