Tesla Model 3 Down: Won't Power Up, and is Inaccessible

[Evoforce]

tekdemon, While you are correct about most applications, the battery jump connection is not located by the battery for Model 3. It is up front by the bumper. There are no battery fumes at that location as it is outside of the front bumper where you pull the jump wires out. I do believe they already have the presented negative wire going to ground.

 

[JRP3]

a few 18650s

You'd need to make sure the cell chemistry is good for sub zero F temperatures. I'd probably go with a high quality small AGM lead acid, like an Odyssey. Charge profile would match up to the existing 12V system without dedicated control circuitry.

 

[TEG]

tekdemon, While you are correct about most applications, the battery jump connection is not located by the battery for Model 3. It is up front by the bumper. There are no battery fumes at that location as it is outside of the front bumper where you pull the jump wires out. I do believe they already have the presented negative wire going to ground.

That is just to trigger the frunk open mechanism. He is talking about once you get it open and the battery uncovered, a procedure to jump the whole car, not just the frunk opener.

 

[MP3Mike]

tekdemon, While you are correct about most applications, the battery jump connection is not located by the battery for Model 3. It is up front by the bumper. There are no battery fumes at that location as it is outside of the front bumper where you pull the jump wires out. I do believe they already have the presented negative wire going to ground.

Actually I don't think the wires in the front are the jump connection, they are just to open the Frunk. Then, according to the manual, you are supposed to hookup your jumper cables directly to the battery in the Model 3.

 

[TEG]

There could be a market for a "backup 12V" that you mount in the frunk with velcro. A simple control board to keep it charged and monitor the charge from the main 12V battery, a few 18650s, and a solid state relay. Upon detecting a below nominal current from the main battery, it closes the relay and "jumps" it for 30 seconds and turns off. Or, enough time to pop the frunk, open the doors, and maybe even get the car powered up. At the very least, it could be a fun way to void your warranty.

At that point I would be thinking about hooking up a nylon pull cord to the hood release and make it work like a Model S so you don't need any aux 12v to open it anymore...

 

[Evoforce]

Actually I don't think the wires in the front are the jump connection, they are just to open the Frunk. Then, according to the manual, you are supposed to hookup your jumper cables directly to the battery in the Model 3.

Being that we were initially trying to get in the car and open the frunk, So, then at that point, what he said generally would apply.

 

[MarkS22]

At that point I would be thinking about hooking up a nylon pull cord to the hood release and make it work like a Model S so you don't need any aux 12v to open it anymore...

True, simple is best. This is something I'm going to have to explore more when I get the car back. I'd feel much more comfortable knowing I had some way to open the doors or even power up the car where I can take it to a safe location.

You can have jumper cables or a backup battery in your Model 3, but no way to access it. It's highly likely you'd find someone to help you out, but I'd prefer to have some option to get back on the road myself.

 

[insaneoctane]

I was frustrated by this possibility and started this thread back in December...
If your 12V battery dies....

 

[arnis]

extremely unsafe way to jump a vehicle and can lead to a dangerous explosion

That's a myth. Old old myth. There must be gigantic hydrogen production for this to happen. And lead connection sequence doesn't change sparking.

There could be a market for a "backup 12V" that you mount in the frunk with velcro.

I do NOT recommend auxiliary lithium pack. This actually is a fire hazard. In case of accident, in case of charging error, in case of temperature etc...
12V lead acid battery that you recharge twice a year will do the trick.
Just keep it at home and if you go on a looong trip, take it with you.

 

[stopcrazypp]

Has anyone tried how much current is required to pop the frunk? Maybe one of those tiny 12V fob batteries is enough, so there is no point to go through all the complicated ways to put a bigger backup 12V in the car.

 

[FlatSix911]

That's a myth. Old old myth. There must be gigantic hydrogen production for this to happen. And lead connection sequence doesn't change sparking. I do NOT recommend auxiliary lithium pack. This actually is a fire hazard. In case of accident, in case of charging error, in case of temperature etc... 12V lead acid battery that you recharge twice a year will do the trick. Just keep it at home and if you go on a looong trip, take it with you.

There are many better options available for a portable 12V lithium power source with a jumper/booster

https://www.amazon.com/s/ref=sr_st_review-rank?keywords=12v+booster+pack&rh=i:aps,k:12v+booster+pack&qid=1518502840&sort=review-rank

 

[K-MTG]

would using a laptop charger (12V) or an equivalent DC power supply be a viable means of power to top off the battery in an emergency?

 

[cwerdna]

would using a laptop charger (12V) or an equivalent DC power supply be a viable means of power to top off the battery in an emergency?

Not sure how many laptop power supplies are 12 volts.

I'm looking at an 85 watt Magsafe Apple AC adapter (usable on Macbook Pros spanning many years) and my Lenovo w/the round plug for old Thinkpads, which work w/newer Thinkpads w/rectangular connector via a cheap adapter. Both have 20 volt output.

 

[AnxietyRanger]

I do appreciate your explanation of how I originally used the terminology, but I agree it became a bigger deal than it needed to be.

I think a historical issue may be that a number of actual attacks on Tesla in the early days made the whole company and many of their early followers wary and defensive in a way that still shows today and does not necessarily garner universal acceptance or appreciation anymore. I think that shows in the exchange.

An unfortunate accident of history.

 

[iwannam3]

That's a myth. Old old myth. There must be gigantic hydrogen production for this to happen. And lead connection sequence doesn't change sparking.

There were front clips of cars in auto shop that the instructor would disable the engine and the students had to figure out and start the engine. After cranking a lot a kid couldn't start it and yanked the battery charger cables off the battery in frustration and all 6 caps blew off and hit the ceiling.

Preventing battery explosions

 

[aarongldng]

Oh no.... here we go again. Maybe we should start a new thread voting on what to call them?

A humble request that us non-previous-owner-line-standers aren't included in the mundanes/muggles/whatever group!

Maybe we need a general terminology thread?

(Also more seriously, thank you OP for having the patience to see the issue through properly)

 

[buttershrimp]

I just went to my garage to make sure it's real... and it's... not... there. It was there this morning. At least, I thought it was... but I have no memory of driving it for days. Everything has been a blur. I see ice. And bricks. Even the title of this thread isn't what I remember typing. Is it Berenstein Bears or Berenstain Bears? What timeline is this? Desmond is my constant.

DANG DUDE! Now I have to cancel my order! Everytime I see the light at the end of the tunnel, Elon slams it shut. I have to cancel now.

 

[RayK]

That's a myth. Old old myth. There must be gigantic hydrogen production for this to happen. And lead connection sequence doesn't change sparking.

Yes, the procedure will not change the occurrence of a spark. That's not the intention. This is the recommended procedure when jump-starting a vehicle (connecting one charged battery system to a depleted one) as far as I can remember it:

1) Insure that the vehicles are not touching each other.
2) Connect jumper cable to positive terminal of donor car to...
3) Positive terminal of dead car.
4) Connect jumper cable to negative terminal of donor car to...
5) Unpainted bolt, frame or engine block of dead car and NOT the negative terminal of the dead battery.

The reason? When there is a spark then it's far away from the battery where there MIGHT be some hydrogen gas. You understand that H + spark sometimes equals 'boom', right?

 

[Drewflux]

Only specialized jumper pack batteries that have specific circuitry to prevent sparking (and which don't off-gas hydrogen themselves) should ever be connected negative to negative, when jumping with another car you should NEVER do connect the negative terminals to each other.
.

Unfortunatly most cheap jump starters will still arc if you accidentally leave them turned on. The internal relay is not ment to close the high current contact untill connection is made but you get what you pay for.

The other thing to think about is the positive lead can also arc. Not just the negative lead. Quite often the lead clamps are oversize and dont make the best connection

All you need for a spark or arc is a potential voltage difference.

 

[Candleflame]

The Model S and Model X have deep cycle batteries. I see no reason why the 3 wouldn't as well. Do you have some reason to assume it doesn't?

I totally agree a lithium 12v would be an improvement but it's totally out of the price range for the "cheapest Tesla ever".

i thought the 2013 Model S had some really cheap low watthour battery? (40ah or smth like that?)