16v Lithium battery Weber State Video

Just released is a detailed, but not overly technical, video about the 16v aux lithium battery for those who have it in newer Teslas.
The video has timestamps for easy access to pertinent information. Of most interest might be:

1:50 The jump-start terminals of the Model 3
2:18 Owner's manual jump-start cautions
4:18 Mislabeled 16V batteries
5:29 MUST SEE: Differences between 16V Li-Ion abs 12V Lead Acid battery
7:45 MUST SEE: The push-fit battery 16V electrical connector
8:55 The jump-start terminals of the Model Y
9:28 The Internal self-protection mode of the 16V battery
11:10 MUST SEE: Conditions for the MOSFET to open in protection mode
15:17 What alert is displayed with a bad 16V battery?
15:42 How to recover a 16V battery with an open MOSFET
16:08 The owner's manual method of recovery
17:47 The service manual method of recovery
18:15 Disconnecting the 16V battery
21:12 The Toolbox 3 and service mode methods of recovery

My model 3 is of the legacy 12v system, I found this video quite fascinating and informative.

 

[jjrandorin]

I dont mind the debate back and forth, but the quasi personal attacks need to stop. I am making this as a general statement because there is more than one person doing it.

Debate, sure, but leave the other stuff out (and yes I plan on enforcing this request).

 

[n2mb_racing]

True. All I had to do was click on your link.

View attachment 927049

Pro tip: When making up garbage and pretending to know things that you clearly don't, don't use words like "are" in bold lettering. Instead, use words like "maybe" and symbols like "~" and "?" to indicate that you are just speculating about a possibility.

I don't see the economizer numbers posted there, but here's another contactor with a built-in economizer.

http://www.thunderstruck-ev.com/images/companies/1/Switch-Relay/EV200%20Kilovac.pdf?1660688661072

It's only rated for 500A, so that would need scaling up to match the Model 3 contactor, but it only consumes 1.7W of hold power. I'd say hold power of <5W per contactor would be reasonable.

 

[gearchruncher]

Here's a solid video from Bjorn where he discusses the sleep vs sentry battery draw:

He calculates 14W for an asleep Tesla, in terms of actual loss from the battery cells. Which means some of this is BMS power and other internal battery loads. I just walked down to my own car and it's drawing 0.6A from the 12V battery while it's asleep (current clamp on the +wire from the battery). That's about 8W @ 13.5V.

So if there's a "trickle" charger, it's supplying less than 6W, assuming all 14W is outside the battery. Seems like 6W for the BMS is reasonable. So it's interesting to try and identify where the trickle charger is, and what kind of power it can source if it's capable of 6W or less but not 14W.

Also, here's an image right from Tesla's own service menu. Notice that it shows the contactors as inline with the PCS, and there's no "small" DC/DC that bypasses the contactors. There is just no evidence that Tesla can "trickle" charge the 12V/15V battery without the contactors closed, and all the loads associated with that.

 

[DM231191]

Hi, I have a question. Do you know if I can safely use my devices with the power socket in my Tesla Model Y with a 16V Li-Ion battery?

I'm talking about a Belkin Car charger which you normally connect to a 12V socket. And I also have a fridge, a Mestic MCC-35. Can I use this fridge safely in my Model Y ? I can't really find any information about it.

 

[n2mb_racing]

Hi, I have a question. Do you know if I can safely use my devices with the power socket in my Tesla Model Y with a 16V Li-Ion battery?

I'm talking about a Belkin Car charger which you normally connect to a 12V socket. And I also have a fridge, a Mestic MCC-35. Can I use this fridge safely in my Model Y ? I can't really find any information about it.

It depends on the device. You have to look up the max voltage for each one. Most will work.

 

[DM231191]

It depends on the device. You have to look up the max voltage for each one. Most will work.

Neither of these devices specify 16V. Only 12V or 24V.

 

[n2mb_racing]

Neither of these devices specify 16V. Only 12V or 24V.

They usually have an operating range listed on the specifications sheet, including a maximum voltage. The charger will be fine.

The fridge, looks like it should work since it says it will work on 12V or 24V.

https://www.mestic.nl/bestanden/artikelen/1/105_1502940M.pdf?1651834596=

Automotive electronics are supposed to be designed to tolerate up to 24V inputs, in case someone jump starts their car from a 24V truck. Some inverters will shut down at 16V, though.

 

[DM231191]

They usually have an operating range listed on the specifications sheet, including a maximum voltage. The charger will be fine.

The fridge, looks like it should work since it says it will work on 12V or 24V.

https://www.mestic.nl/bestanden/artikelen/1/105_1502940M.pdf?1651834596=

Automotive electronics are supposed to be designed to tolerate up to 24V inputs, in case someone jump starts their car from a 24V truck. Some inverters will shut down at 16V, though.

Hmm.. still not convinced..

 

[n2mb_racing]

Hmm.. still not convinced..

Plug it in and find out.

If you have something that is low current and needs exactly 12V, best bet would be to use the UBS-C plugs. There are USB-C PD cables that will deliver 12V for small stuff.

The fridge needs to go direct to the 12/16V power outlet.

 

[gearchruncher]

Automotive electronics are supposed to be designed to tolerate up to 24V inputs, in case someone jump starts their car from a 24V truck.

This isn't true. I dare you to hook 28V (the actual voltage a 24V system runs at) to your car and run it for an hour.

The overvoltage jump start condition is considered the most extreme case to handle, and is only required to be handled for 5 minutes. It's also voluntary, and particularly for devices not built into the car, there's zero reason to assume they would adhere to this standard.

https://m.littelfuse.com/~/media/electronics_technical/application_notes/varistors/littelfuse_suppression_of_transients_in_an_automotive_environment_application_note.pdf

For instance, there is no way that a 12V incandescent light bulb would survive this. Simple resistive devices will draw 4X the power at 24V, and none of them will survive that.

There's really only two ways to know if an accessory made to plug into a "12V" cigarette lighter will survive a "15V" circuit:
1) Have the manufacturer tell you via a datasheet
2) Try it.

But I do also agree it's highly likely to work. Even "12V" systems are actually almost 15V. An AGM battery at full charge can be 14.8V. The extra ~1V that the newer Tesla architecture has is unlikely to break a "12V" device. But you can't 100% be sure.

 

[n2mb_racing]

This isn't true. I dare you to hook 28V (the actual voltage a 24V system runs at) to your car and run it for an hour.

The overvoltage jump start condition is considered the most extreme case to handle, and is only required to be handled for 5 minutes. It's also voluntary, and particularly for devices not built into the car, there's zero reason to assume they would adhere to this standard.

https://m.littelfuse.com/~/media/electronics_technical/application_notes/varistors/littelfuse_suppression_of_transients_in_an_automotive_environment_application_note.pdf

For instance, there is no way that a 12V incandescent light bulb would survive this. Simple resistive devices will draw 4X the power at 24V, and none of them will survive that.

There's really only two ways to know if an accessory made to plug into a "12V" cigarette lighter will survive a "15V" circuit:
1) Have the manufacturer tell you via a datasheet
2) Try it.

But I do also agree it's highly likely to work. Even "12V" systems are actually almost 15V. An AGM battery at full charge can be 14.8V. The extra ~1V that the newer Tesla architecture has is unlikely to break a "12V" device. But you can't 100% be sure.

That's why I said tolerate.

I design automotive electronics and I designed mine to tolerate 24v without damage.

 

[Tom_JS]

John Kelly is the MAN! I especially loved his series on the first mass produced Automatic Transmission. The Gm Hydramatic. It’s amazing how those guys basically invented these parts from nothing and most of those parts and concepts are still used in todays transmissions! Plus he explains everything perfectly.

 

[rrolsbe]

Yeah, I thought 10kW was a bit absurd. The Kona’s DC-DC draws around 200 watts off the traction battery including the contactors, plus whatever it takes to support the 12V system load.
There must be trade offs between aux battery capacity and the frequency of cycling wear on the charging hardware.
I suggested to John over at Weber Auto that a 24 h 16V system voltage log would be an interesting talking point.
Has anyone tried a BM2 logger on their 16V Tesla?
The primary advantage I’m seeing of Tesla’s 16V system is that its BMS can request support as needed rather than having to rely on a timed query which may be too late to save an auxiliary battery.

Yes the Bluetooth voltage monitor/logger does work connected to the 16V battery. Since it draws appox 2ma the car can sleep almost five days as opposed to six plus days not connected. My 2018 Model 3 never slept more than 31 hours.