Salvage Car Owners Support Group.

[JRP3]

I didn't notice the one I linked to is 24V Found the data sheet, only -10C, (14F), operating temp, so might have issues if your car tries to charge it much below freezing.
https://cdn.shopify.com/s/files/1/0219/0154/files/BLF-1250A_User_Manual_rev_04_23_2019.pdf?209

 

[rooter]

They are honest with their specs and good to deal with. (I bought direct) I notice the data sheet is for the BLF-1250A, not the same as I have.

I'm in the Seattle area and have never had a problem.

What's the temp for LiIon? Lead-Acid?

 

[JRP3]

Most lithium chemistries have a similar limitation, except LiTiO2 which I think goes down to -40, about the same as lead acid.

 

[tyson]

Yeah as much as we accuse Tesla of doing "California engineering" the lead acid is actually a good choice as those of us that have highs in the single digits, sometimes negative, really need it.

 

[JRP3]

Lithium Titanate, LiTiO2, would be ideal, it can handle the temperature and has the highest cycle life, but it's the most expensive choice.

 

[tyson]

Yeah, if they could show a life cycle capacity that justified the cost then I'd be all for that.

 

[JRP3]

How does 20,000 cycles sound? Chart for Toshiba Scib, LiTiO2 cells

 

[tyson]

It sounds like a lot! Though it still needs to be tied back to cost and then compared. I'll do some research later

 

[Calvinb]

@Calvinb Yes that module is out of action, but it's not the main cause. Pack may just need rebalancing. (Charge to 100% and leave it connected for a day -- when over 93% it begins the rebalancing process)

What year? Firmware version? History of the car? Other errors on display?

You will be rooting sooner or later whether you like it or not. If you could put it in developer or factory mode you'd see errors detail.

No idea about the lid sensors since HVJB's have changed radically over the years, but you should never never open that box without taking significant precautions. 400vDC will kill you, dead.

"voltage supply too low" means the 12v battery. Get a charger on that. If you still have a C&D battery it may just be sulphated (end of life - more than a year old?) and can't provide the current the car needs. I've put in a Bioenno LiFePO4 ('Lithium-Iron'), of higher capacity than the C&D (50 vs 35), which nobody's heard of despite my yelling about it, and it has done me very well for years now. Should last 10x longer than the C&D and 2x longer than a LiIon, and can not (by its very nature) burst into flames like a LiIon can. It is expensive... but it costs out very well.

Thanks for the reply.

I have tried charging it but port won’t open. Opened it manually but still nothing when plugged in, tried 7kw and granny cable.
Year: 2015 Software: 19.32.2.2 I think most up to date available in UK.
I can’t get any history on car from Tesla due to GDP regulations. This is a joke as I am now the owner of the car.
Other error is ‘power reduced - vehicle systems shutting down’. See attached screenshot showing all errors.

Yes I have taken caution. We have a pair of 1000v insulating gloves, we are a car dismantlers including electric cars but don’t do any diagnostics.

I bought a new 12v deep cycle battery from Tesla, less than €50.
This new battery made no difference when I connected it. The HV pack won’t charge 12v, it drains and the car shuts off. This happened with the previous battery.
I connected 12v to our fancy snap-on 12/24v charger (on 12v of course), kept 12v topped up but still getting the ‘voltage supply too low’ error.

I thought if I got it into developer mode I could see the problem. I want to get the car rooted but I don’t really have enough experience to get this done. I am teaching myself using your guidance a few hours each evening when I’m free but is going to take a while.

 

[Meeshkra]

Looking at a car that is currently at the auction and has very minimal rear end damage and no airbags deployed. This picture from the auction site of the dash shows some red message on the instrument cluster but I can't decipher what the full text could be. Something along the lines of Service M..... ....eed Limit. Any ideas?

Thanks!

 

[bkp_duke]

SERVICE MODE

SPEED LIMITED


I believe that is the screen text.

 

[rooter]

I bought a new 12v deep cycle battery from Tesla, less than €50.
This new battery made no difference when I connected it. The HV pack won’t charge 12v, it drains and the car shuts off. This happened with the previous battery.
I connected 12v to our fancy snap-on 12/24v charger (on 12v of course), kept 12v topped up but still getting the ‘voltage supply too low’ error.

I thought if I got it into developer mode I could see the problem. I want to get the car rooted but I don’t really have enough experience to get this done. I am teaching myself using your guidance a few hours each evening when I’m free but is going to take a while.

I was afraid of this. Got heat and A/C? These are 400vDC. Does the pack contactor ever click? If all the above it's very possible that your DC to DC converter has blown a fuse. This converts 400vDC to 12vDC to charge the battery, run power steering, et al. Got power steering?

Before you pull the DC-DC though check all the big fuses. These are in the same box as the pyrofuse, below the air intake plenum on the right-side bulkhead. And check the pyro there just for fun. Loosening the fuse nuts means their screws will fall down (yaay Tesla), so you'll need to pull apart the whole fuse box to make it right. (Ask me how I know) Can never test a fuse while its in-line unless power is there. (12v on one side -and- t'other)

The DC-DC is on the bulkhead, right-of-center. Don't remember if there's anything above it, probably is. If you have air suspension you'll need to remove the accumulator tank. You can't have any bones in your arms if you want to get it out, and you have to be able to see around corners. Make sure to drop some nuts so you can go to the hardware store for metric replacements.

Be sure to disconnect + from the 12v battery and the emergency responders' cut-loop before you pull it.

 

[Calvinb]

I was afraid of this. Got heat and A/C? These are 400vDC. Does the pack contactor ever click? If all the above it's very possible that your DC to DC converter has blown a fuse. This converts 400vDC to 12vDC to charge the battery, run power steering, et al. Got power steering?

Before you pull the DC-DC though check all the big fuses. These are in the same box as the pyrofuse, below the air intake plenum on the right-side bulkhead. And check the pyro there just for fun. Loosening the fuse nuts means their screws will fall down (yaay Tesla), so you'll need to pull apart the whole fuse box to make it right. (Ask me how I know) Can never test a fuse while its in-line unless power is there. (12v on one side -and- t'other)

The DC-DC is on the bulkhead, right-of-center. Don't remember if there's anything above it, probably is. If you have air suspension you'll need to remove the accumulator tank. You can't have any bones in your arms if you want to get it out, and you have to be able to see around corners. Make sure to drop some nuts so you can go to the hardware store for metric replacements.

Be sure to disconnect + from the 12v battery and the emergency responders' cut-loop before you pull it.

Yes got both A/C and heat and have already changed the DC/DC converter (bought this from Tesla as I didn’t want to doubt myself with a 2nd hand one. Yes luckily I don’t have huge hands not long out of uni and was able to change this but with great difficulty). Have power steering when the car starts.
I do think the contractors close because coolant starts to run through the car only for a short period and then stops.
Checked all fuses in fuse box and changed the pyrofuse.
This is why I resulted in turning to opening the rear HVJB to continue my search for the problem.

I forgot to mention at the start, I had this car finished and was driving it, put over 1000 miles on it. One night driving home slightly over 100mph got warning ‘rear motor disabled - ok to drive’. I continued (sensible speed) home as I was only about 2 miles away. The rear motor warning disappeared and hasn’t returned since. I wanted to get diagnostics done before I go buy a rear motor incase turns out that also isn’t the issue.

 

[rooter]

Well; it's not magick. It's very important to notice the -clunk- -clunk- of the main contactors. If they don't stay closed we need to know.

And if you get that do you ever get ~14vDC at the 12v battery? To charge a battery you must always apply more than the rated voltage. If you don't see that trace it back to the DC-DC. You have PS so the DC-DC's not totally out of action, and with A/C and heat (400vDC) the contactors are making, at least at first.

The car is turning on. (PDNR), so is adequate charging voltage ever making it to the 12v battery? Are the contactors staying closed?

Beyond this you just need more info. (Dev or Factory mode)

 

[bkp_duke]

The contactors are an isolated component in side the HV pack. I've never seen them welded closed, although they can get locked into place if they are dying.

It would take an extraordinary amount of effort to weld the contactors closed.

 

[bkp_duke]

The vehicle gave a diagnostic code saying they were welded and the Pyro fuse blew

What model car, approximate VIN, and build date of car? Original pack? Contactors never replaced?

 

[MP3Mike]

Can a battery pack be isloated if the contractors are welded closed, i think a Tesla service centre have messed up my car and i need to get to the bottom of it.

Not that I am aware of. You would have to drain the battery and take it out and replace the contactors.

What do you think they did?

 

[bkp_duke]

That is a late enough VIN that it should not have the old Tyco contactors (which are prone to burning up and getting locked - usually in the disconnected position).

I've never heard of the Gigavac contactors burning out, but it is possible.

 

[Bubb1es]

I think the software was corrupted on the vehicle and they received an echo voltage before i discharged it. The vehicle wouldn't update software and i couldn't get it to give the outside air temperature or change the name.

 

[bkp_duke]

Thanks for that information. Totally stupid question but the 12v Battery connected to a trickle charge couldn't reverse charge the pack in anyway if it was discharged and the contactors were welded. I'm trying to cross out every possibility.

No, that would be like filling the ocean with a thumb dropper. The resistance would probably mean that anything that made it back to the pack would be lost as heat.