Reviving the possibilities of onboard battery extender

[mongo]

Ok, then maybe in addition to those panels, your trailer in that circumstance needs to be carrying a tank of propane and the ability to convert that to juice. Or an additional battery like the pebble idea.
Point is still that the solution would be customizable to your particular range dilemma rather than force an entire fleet of cars to carry a battery as a solution which solves the problem for the one owner who chose to tow an 8x32ft trailer but not for those who have a different range problem to overcome like towing a boat to and from a lake which is not that close to a supercharger, or making it across BC to the next charger on an Alaska trip or making it to a remote job site with enough juice left to power your construction equipment etc.
Customize the energy supplementation to the particular problem.

Sure, and adding 48V LFP batteries to the trailer maximizes total payload.
Can also put the LFP in the truck bed and/or frunk.
5kWh per 100 pounds. Nice and modular. Super easy to integrate if you can deal with 11kW charge transfer rate (inverter to wall connector) or 7kW (inverter to mobile connector) while stationary.

Theoretically, the current PCS charger could handle 48V - 320V DC input and provide stationary or in motion charging (disables outlets though).

Otherwise add on 48V to 800V converter.

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[hemiarch]

Sure, and adding 48V LFP batteries to the trailer maximizes total payload.
Can also put the LFP in the truck bed and/or frunk.
5kWh per 100 pounds. Nice and modular. Super easy to integrate if you can deal with 11kW charge transfer rate (inverter to wall connector) or 7kW (inverter to mobile connector) while stationary.

Theoretically, the current PCS charger could handle 48V - 320V DC input and provide stationary or in motion charging (disables outlets though).

Otherwise add on 48V to 800V converter.

Does the mobile connector really max out at only 7kw? Didn’t realize that. Always imagined the limitation was the power source.

 

[mongo]

Does the mobile connector really max out at only 7kw? Didn’t realize that. Always imagined the limitation was the power source.

I truncated, 32A @ 240V : 7.68kW max
Early Tesla MC were 40A (80% derating of 14-50 50A), but they reduced it.
Jowua has a 40A MC.

 

[hemiarch]

I truncated, 32A @ 240V : 7.68kW max
Early Tesla MC were 40A (80% derating of 14-50 50A), but they reduced it.
Jowua has a 40A MC.

Good to know. Thank you. Still have the MC from our 2016 model x. It came in a round mesh-ish bag. Will carry that instead of the slimmer square soft case moving forward.

 

[CT_AZ_4x4]

Ok, then maybe in addition to those panels, your trailer in that circumstance needs to be carrying a tank of propane and the ability to convert that to juice. Or an additional battery like the pebble idea.
Point is still that the solution would be customizable to your particular range dilemma rather than force an entire fleet of cars to carry a battery as a solution which solves the problem for the one owner who chose to tow an 8x32ft trailer but not for those who have a different range problem to overcome like towing a boat to and from a lake which is not that close to a supercharger, or making it across BC to the next charger on an Alaska trip or making it to a remote job site with enough juice left to power your construction equipment etc.
Customize the energy supplementation to the particular problem.

Customizable energy supplementation is how I viewed the range extender. If Tesla is making batteries, like they do for Powerwalls, it would not be a gigantic leap to offer batteries as range extenders. I’m thinking comes down to where their focus is at.

Are they a robotics company? Are they an AI company? Is their real goal the transition to sustainable energy? Are they a vehicle manufacturing company?

It seems to me that Tesla as a business needs to hone its capabilities to a centrally focused business goal or two, instead of five or six goals.

And before the caterwauling begins, in my defense I’ve not said anything bad about anyone’s mother. I’m an Elon and Tesla supoorter. But this entire range extender conundrum is an indicator of larger issues.

How on God’s green earth is Chevy offering a pickup with 30%+ greater range than a Cybertruck?!? And we’re not even beginning to compare Chinese EVs with American-made EVs. Who is eating whose lunch? And the Chinese aren’t even at the lunch counter, yet.

 

[hemiarch]

I hear you and agree with all that Jay except for the ambiguity. Straight from the horses mouth, Tesla should be regarded as an AI and robotics company no?
Am I misunderstanding or misappropriating what he’s on record as saying?

 

[HaulingAss]

How on God’s green earth is Chevy offering a pickup with 30%+ greater range than a Cybertruck?!? And we’re not even beginning to compare Chinese EVs with American-made EVs. Who is eating whose lunch?

Wait...you're not talking about the Chevy pickup that has lower sales than the Cybertruck and loses tens of thousands of dollars for every one sold, are you? You know, the Silverado that doesn't come with a tonneau cover, let alone one that opens and locks automatically?

I don't generally refer to products that sell in very low numbers (and for less than they cost to manufacture) as eating anyone's lunch! Why would they sell them for less money than they cost to make? Oh, because that's all truck buyers are willing to pay for them.

And why do most Silverado buyers buy the shorter range versions?

 

[CT_AZ_4x4]

Wait...you're not talking about the Chevy pickup that has lower sales than the Cybertruck and loses tens of thousands of dollars for every one sold, are you? You know, the Silverado that doesn't come with a tonneau cover, let alone one that opens and locks automatically?

I don't generally refer to products that sell in very low numbers (and for less than they cost to manufacture) as eating anyone's lunch! Why would they sell them for less money than they cost to make? Oh, because that's all truck buyers are willing to pay for them.

And why do most Silverado buyers buy the shorter range versions?

What is your point? Be clear.

I think you are trying to say that the Cybertruck is an unmitigated success and that the technical ability of Chevrolet to give a pickup truck greater range means nothing.

And that Chinese EVs are not becoming superior technologies to anything American-made.

Or are you just looking to argue baselessly?

 

[YDR37]

If Tesla is making batteries, like they do for Powerwalls, it would not be a gigantic leap to offer batteries as range extenders. I’m thinking comes down to where their focus is at.

There are only 50,000-60,000 Cybertrucks on the roads today, and sales appear to be slowing down. Realistically, what percentage of CT owners would be prepared to pay $16,000+ for a huge battery that weighs several hundred pounds and eats up much of your bed volume and payload?

I'm sure there are some, just not very many. I think 10% is a generous estimate, and even in that case, we are only talking about 5,000-6,000 customers.

There are legitimate questions about Tesla's focus. But I'm pretty sure that it is not on those 5,000-6,000 people.

If Tesla still has any focus on vehicles, it's on the Model Y and Model 3, which collectively accounted for over 97% of global vehicle sales in 2Q 2025. The Cybertruck is just a tiny fraction (less than 1.5%) of Tesla's global sales, and the potential range extender market is only a small fraction of that tiny fraction.

 

[HaulingAss]

Realistically, what percentage of CT owners would be prepared to pay $16,000+ for a huge battery that weighs several hundred pounds and eats up much of your bed volume and payload?

I'm sure there are some, just not very many. I think 10% is a generous estimate, and even in that case, we are only talking about 5,000-6,000 customers.

Exactly! Not only do most buyers not have the money for a battery range extender, most wealthy buyers know they have no need for a battery extender, and don't want one anyway.

If Tesla still has any focus on vehicles, it's on the Model Y and Model 3, which collectively accounted for over 97% of global vehicle sales in 2Q 2025. The Cybertruck is just a tiny fraction of global sales, and only a small fraction of CT owners would actually buy a range extender.

Exactly! And all this crazy talk about the Chinese passing up Tesla in EV technology is just hot air that is contradicted by Q2 Chinese auto sales figures. The most recent sales data shows the Model Y is the best-selling vehicle in China, outselling every cheaper Chinese vehicle, gas or electric, by a large margin.

If we are to believe the negative narratives spread by the anti-Tesla crowd, the Model Y, a less advanced EV, is outselling more advanced Chinese EVs by a large margin, and all Chinese gas cars, that cost 1/4 to 1/2 as much.

Are we to believe Chinese new car buyers are ignorant? The false narratives being spread are incredibly prolific, both on forums and in the mainstream media, but they don't change the actual reality on the ground. They are just pathetic in their hate for Tesla when they hold Chinese automakers in higher esteem than the true leader in the EV space, both from a technological perspective and also in the ability to bring real value to new car buyers. Just pathetic.

 

[YDR37]

this crazy talk about the Chinese passing up Tesla in EV technology is just hot air that is contradicted by Q2 Chinese auto sales figures. The most recent sales data shows the Model Y is the best-selling vehicle in China, outselling every cheaper Chinese vehicle, gas or electric, by a large margin.

Seems like this thread is getting a bit off-topic, but out of curiosity, what is your source for Q2 2025 China car sales data?

 

[Outdoors]

It you are Tesla, it almost is that simple (plus a few contactors, DPDT switch, and monitor ECU) along with splicing in the thermal system.
Generic brand extender interface requires 40kW isolated bidirectional converter connected to the HV bus.

Last day trip to inlaws required > 92% SOC in summer to get from Supercharger back to Supercharger. No trailer, no weather issues.
Last fall, limped back to charger at single digit SOC by driving under the speed limit and bypassing the expressway.


You say that like it's a bad thing ?
Don't you calculate axle and tongue loads before (not) buying a trailer?

That's you driving on the freeway. Cybertruck with off-road tires and such. In my mind Cybertruck wasn't meant for freeways. Sounds like new in-laws are in order. Maybe ones that live on 35-45 mph dirt roads as I was stating. Range is really plus 300 in that world. Bypassing a freeway still is 55-65. Not 35-45 which I would say is more like epa. Yet we all know epa isn't real world. It is for me.

Maybe buy in-laws a wall charger...?

Nerds. No I don't calculate that stuff. I rely on trailer professionals to calculate my setup. Many people think they are experts on towing yet never had. Go to Internet and they calculate. That isn't smart. Having towed well over a hundred k. I am glad I let them inspect my rig annually when I used to tow...

 

[YDR37]

The 2Q 2025 Tesla earnings call is scheduled for tomorrow. Retail investors have been submitting questions for Tesla management. And the investors have submitted a surprising number of questions/concerns about Cybertruck range:

There is no assurance that any of these questions will actually be raised in the call, or that management will provide a straight answer if they do get asked. We'll find out tomorrow.

I didn't catch any news about the Cybertruck at all, either in the 2Q 2025 shareholder deck or in the earnings call transcript.

There was mention of "volume production of more affordable models" in 2H 2025. That could potentially include the RWD Cybertruck, although no specifics were provided.

 

[CT_AZ_4x4]

I didn't catch any news about the Cybertruck at all, either in the 2Q 2025 shareholder deck or in the earnings call transcript.

There was mention of "volume production of more affordable models" in 2H 2025. That could potentially include the RWD Cybertruck, although no specifics were provided.

The WSJ suggests that the stripped Cybertruck is at least one of the “more affordable models…”.

 

[YDR37]

It's not Cybertruck-related, but one bit of exciting news that did come out of the 2Q 2025 earnings call was about the "hyper-exponential" expansion of Tesla's autonomous robotaxi service:

Elon Musk: As we get the approvals and prove out safety, we will be launching the autonomous ride-hailing across most of the country. I think we will probably have autonomous ride-hailing in probably half the population of the US by the end of the year. That's at least our goal, subject to regulatory approvals. I think we will technically be able to do it. Assuming we have regulatory approvals, it's probably addressing half the population of the US by the end of the year. We are being very cautious. We do not want to take any chances, so we are going to go cautiously. But the service areas and the number of vehicles in operation will increase at a hyper-exponential rate.

At this point, most Americans have never even seen a robotaxi. And yet, if you live in the US and are reading this post in July 2025, there's a 50% chance that you will gain access to Tesla's autonomous robotaxi service from your home or work during the next 160 days.

It's almost unbelievable.

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