Reviving the possibilities of onboard battery extender

[Oden's Beast]

I believe the "off-grid camping" scenario I was responding to was separate from the long-distance towing scenario. It was @Oden's Beast who put forth the idea that staying within 100-120 miles miles of a Supercharger when in the backcountry was a big limitation. When I'm in backcountry areas I'm generally on roads with a maximum speed limit of 50-60 mph and my Cybertruck gets well over 300 miles of range from a full charge overnight. I responded to the towing limitations separately. People who tow a big trailers a lot, anywhere but short trips, know enough to buy a 3/4-ton to 1-ton truck (or heavier) depending upon the exact application.

The fact that the Cybertruck handles exceptionally well towing heavy trailers right up to it's rated limit (unlike other 1/2-ton trucks), does not automatically make it the right tool to tow big trailers over the open road. IMO, not even the Silverado EV with the 220 kW battery is good at doing that. People who know what they are doing already know this. I'm not sure why @Oden's Beast seems to think a range extender would make a dent in the problem. If the 220 kW of the Silverado can't make it good for towing travel trailers long distances, why does he think a battery range extender would?

It makes no sense.

I'm so glad Tesla didn't try to accommodate a niche use case (heavy, long-distance towing) that would have automatically disqualified it from being a good off-road truck. The Sierra/Silverado's with the big battery are literally incapable of traversing difficult terrain that is a cake-walk for the Cybertruck. This is not hyperbole, it's the honest truth, they are complete dogs off-road, even the Trail Boss that pretends to have off-road aspirations. The Cybertruck is the real deal.

Exactly what Mongo just said, and…

Oh, now you’re omnipotent, and assuming I’m even talking about hauling large travel trailers(?). I’ve been purposefully talking very generally about its towing ability, I never mentioned hauling a max load rated trailer across the country (?). But hey, if you feel it helps sell your narrative and your use case as to why it is absolutely the perfect “truck” as it is…. feel free to say that I’m hauling something at max capacity, please go for it.

By the way, if I was actually hauling a 35’ travel trailer across the country, I’d use a truck rated to match it.

For reference, one of the things I do haul is a Keifer Built horse trailer, a two horse unit. Empty weight is right at 3,000 pounds, with two of my horses and tack, it comes in at just over 5,000 pounds. Hardly F-250 or 350 Territory. This trailer loaded, is less than half the rated capacity of the truck. Is that enough safety factor for you? I am lucky to get 100 miles from 100% state of charge, just over 80 miles from a 80% charge (it’s a sail). I went to Ocala National Forest to ride them with my wife, that’s normally only a three and a half hour drive for me, roughly 230 miles. My drive time literally doubles hauling with this “truck”. So now, I have horses stuck in a trailer, nearing the max time that they really should even be in the trailer. That extra 25% range would eliminate one of those stops completely, and cut my travel time accordingly. I don’t think that’s a big ask. I literally used this trip as one of the use cases in my calculations to buy.

Yes, it was me talking about overlanding. Here again, that extra 25% enables multiple more days on the trail without having the extra anxiety of “will I make it back out“… “let’s cut our trip short…so we can go charge”. That alone was worth its price to me. Now I’ll likely be bringing in generators and listening to their hum rather than nature. Yay! Or more likely, using a different vehicle.

Also, for driving down maintained or partially maintained forest service roads, I agree, the CT is awesome for this. But honest to goodness hard core off roading, with its long wheel base and overhangs (see Jeep, Broncos, Toyota/Lexus, Land Rover, G wagons, etc) and its heavy weight, it is hardly the perfect vehicle for doing this at any extreme either.

It’s a compromise for the extremes, it does most other things extremely well, they did great trying to get the best possible outcome for each, and it does them really good.

It seems (maybe I’m wrong) that you also feel that me wanting a longer range vehicle is somehow going to affect Tesla’s profits(?). Is that your position?

You do understand that I was (and still am) willing to pay them a substantial amount of money for this option, I was not asking for a subsidy from them, you realize this right?

Tesla is not shy at all on ensuring they sell vehicles or accessories at a profit. I was, and still am, willing to pay their asked price for this option, not sure how this negatively affects their financial performance or risks shareholder value,

I guess I’m just missing the point on this one too, above my pay scale. Silly of me to think they, a global manufacturer, would have the engineering and management skill set, to actually BOM cost out an option and determine it’s profit margin and sale price before launch. How naive of me.

All I wanted was to pay them a lot, for a little more range, but I guess that’s not reasonable of me to now ask for. I’m truly sorry that me still asking them for this true ER option, upsets you so much.

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[hemiarch]

So I know this thread is about the range extender battery, but didn’t Elon talk multiple times about adding solar mechanisms like a “solar tonneau” that would slow how quickly the battery gets drained?
If you’re towing a trailer, doesn’t that also mean you’re adding a bunch of roof surface area to the rig which can be covered in solar? Let’s think outside the battery box here for a second.
All they would really need to do is produce an input mechanism with adequate specs for plugging a fair amount of solar into the truck while driving.
MPPT inputs are pretty standardized and can accept a whole range of voltages and currents depending on how they are set up. They can even potentially accept energy generated through combustion and turned into electricity. How many videos are there out there of people using propane and gasoline/diesel generators and such in Alaska? What if hydrogen becomes more prevalent and people start selling generators that work on that? So why not make this party BYOES? (Bring your own energy source).
Meet the input specs or go home type scenario.
The barrier right now as I see it, is that there is no way to get that energy into the HV battery while driving. This is a barrier that can be engineered away though. They would have had to do that for the battery extender anyway.
In my opinion it would be an even better solution than more battery capacity because it means you don’t have to haul around the extra battery and live with the decreased bed space or generator/solar weight or increased aerodynamic resistance when you’re not towing.
So…just because they cancelled the range extender doesn’t necessarily mean they have abandoned any possibility of increased towing range on the CT.
Maybe I’m too much of a glass half full kind of guy and maybe I’m giving Tesla too much credit because I’m gullible but that’s how I choose to look at it.

 

[HaulingAss]

Oh, now you’re omnipotent, and assuming I’m even talking about hauling large travel trailers(?).

Forgive me if I assumed you were talking a large trailer because you said the Cybertruck would only have a maximum range of only 120 miles when towing. Based upon what I know, that implied a large trailer.

I get you point, but as someone in that minority, who actually would like to tow his trailer further than 120 miles, or actually go off grid camping for multiple days at time (and not have to hyper calculate or always be within 100-120 miles of a supercharger).

If you can only get 120 miles of range out of a Cybertruck while towing a lighter, mid-sized (non-travel) trailer, then I would suggest you check your setup to see what's wrong. Or maybe you just need to slow down a little bit.

It seems (maybe I’m wrong) that you also feel that me wanting a longer range vehicle is somehow going to affect Tesla’s profits(?). Is that your position?

Absolutely not, your wants and desires don't affect Tesla's profits at all. Not even a little bit. That's personal to you and you alone. Tesla is not trying to be everything to everyone, they are trying to hit the sweet part of the market. Every other EV truck maker loses money, a lot of money. The ones with the biggest batteries lose the most money per truck. So tell me why Tesla should do what YOU want them to do, instead of what the sweet part of the truck market wants them to do.

You do understand that I was (and still am) willing to pay them a substantial amount of money for this option, I was not asking for a subsidy from them, you realize this right?

You don't have enough money to incentivize Tesla to do something they wouldn't otherwise do. Tesla is not in the business of filling niche market needs, they are a mass-market manufacturer/seller of high volume vehicles. As it stands, even the mass market version of the Cybertruck is on the margins of what I would consider a mass-market vehicle and they have made the decision that a range extender is not going to improve the volume metrics enough to make it worthwhile. Just because you have a "substantial amount of money" doesn't mean they have to cater to your personal needs. They are the ones that decide how to invest their capital in the most productive manner. When you are in charge of your own auto company, then, and only then, do you get to deploy capital how you see fit.

Tesla is not shy at all on ensuring they sell vehicles or accessories at a profit. I was, and still am, willing to pay their asked price for this option, not sure how this negatively affects their financial performance or risks shareholder value,

I can tell you have never been a manufacturer of large, complex items, like vehicles and batteries. You simply fail to understand the business, including the risks and potential rewards. Tesla is very good at this, that's why they get to make the call, not you. It's not even your capital that would be at risk should Tesla decide to start to catering to relatively niche needs that most people don't want or need. That's why you don't get to decide how they deploy capital.

I guess I’m just missing the point on this one too, above my pay scale. Silly of me to think they, a global manufacturer, would have the engineering and management skill set, to actually BOM cost out an option and determine it’s profit margin and sale price before launch. How naive of me.

On that we agree! Because profit margin and price are dependent upon volume of production/sales. This is what I think you must be missing.

All I wanted was to pay them a lot, for a little more range, but I guess that’s not reasonable of me to now ask for. I’m truly sorry that me still asking them for this true ER option, upsets you so much.

It doesn't upset me at all that you are asking Tesla to give you an option to pay a lot of money for a little more range. But it's beyond disconnected if you think that simply asking for something that most people don't even want or need, entitles you to it. What is it that you don't understand about "no"? It's Tesla's call, not yours.

 

[hemiarch]

None of my business but while almost everything you are saying is true @HaulingAss , this is a little colored by the fact that they DID actually offer a range extender and they DID take peoples money for it implying they were going to do it . Many peoples decision to buy the Cybertruck was influenced (apparently pretty heavily) by this.
That’s hustle no matter how you look at it and I understand why many are pissed.
I still think this problem is solvable without a huge battery addition though.

 

[HaulingAss]

So…just because they cancelled the range extender doesn’t necessarily mean they have abandoned any possibility of increased towing range on the CT.

Historically, Tesla has often increased the range of their vehicles after their initial release. Sometimes it's simply fine-tuning things to increase drive efficiency, sometimes it's because they have access to batteries with a bit higher energy density at favorable prices. Technology continues to improve and batteries are on a long slow cost decline, adjusted for inflation especially.

The only thing Tesla has cancelled is the initial concept to have an add-on range extender that sits in the bed. I think it's very unlikely that they revive that idea, even if it's theoretically still possible. I think they determined the cost curve (price to volume) did not intersect the demand curves at those prices and volumes. I suppose it's possible that could change, but I think the real cost issue they ran into probably involved the cost of supporting such a low volume product. And, it's kind of a "hack add-on", not really as safe, effective or reliable as simply having a bigger traditional battery integrated into the chassis and utilizing a more unitized battery thermal system. I never really thought an add-on battery made a lot of sense, considering the complexities involved with software and coolant thermal management connections, high-voltage connections, cargo load management and it's impact on tongue limits, etc.

Kludging on an extra battery is not as simple as connecting the red wire to the positive and the black wire to the negative.

 

[hemiarch]

I get that. I’m just saying as I stated above that I’d rather have charging access to the HV battery while it’s working through a charge controller than any sized add on battery.
That would mean I can tailor my solution to my specific range problem and also makes it less of a niche solution.
Agree, they are not going to bring the extra battery idea back but I don’t think that necessarily means they have abandoned the towing range problem. There are other ways to solve that.

 

[HaulingAss]

None of my business but while almost everything you are saying is true @HaulingAss , this is a little colored by the fact that they DID actually offer a range extender and they DID take peoples money for it implying they were going to do it . Many peoples decision to buy the Cybertruck was influenced (apparently pretty heavily) by this.
That’s hustle no matter how you look at it and I understand why many are pissed.
I still think this problem is solvable without a huge battery addition though.

As I already mentioned, there is nothing wrong with cancelling a product before it reaches production ramp and refunding any deposits. And if people thought that Tesla was obligated to produce the range extender, no matter how the market changed, or what they learned about the true cost to release such a product, well, I would just suggest they must be a little green behind the ears. Common sense says their is no guarantee an announced product, will pan out. In fact, I cautioned against that possibility shortly after Tesla announced the concept and was actively taking deposits for reservations. If you read the reservation agreement, you will see the product was never guaranteed to be made available. The only remedy was a refund of the deposit money.

What do people not understand about this and why do they feel entitled to things the reservation deposit did not grant?

 

[hemiarch]

I certainly understand that. Those deposits were essentially kickstarter money.
That said, there is a relationship between the range extender panning out and some people’s decision to shell out $100k for the cybertruck itself.
I don’t agree with that but that’s what they are claiming. “I wouldn’t have bought it if I didn’t think there was going to be more range available eventually”

 

[Outdoors]

I have been trudging around the wet mountain west for the last 3 weeks in my @cyberttruck co. Mostly below 25-35mph. All off road and two track and using a Eco Flow Delta to power everything else.

See very little need for a range extender. Most that talk boondock just want to drive and drive, and are scared cats of being out in the woods without an extra hundred miles of range when they hit destination. I think many are just calculating nerds. The truck does fine for range if one is traversing like a cybertruck should.

Would I have enjoyed the range extender? Sure, as it would have been not DIY as all the crazy ideas I see here. Would still be able to puyt a Eco Flow in the back and have more.

I certainly understand that. Those deposits were essentially kickstarter money.

Tesla needing kickstarter money. Good one for a laugh. Did you really type that?

 

[hemiarch]

I have been trudging around the wet mountain west for the last 3 weeks in my @cyberttruck co. Mostly below 25-35mph. All off road and two track and using a Eco Flow Delta to power everything else.

See very little need for a range extender. Most that talk boondock just want to drive and drive, and are scared cats of being out in the woods without an extra hundred miles of range when they hit destination. I think many are just calculating nerds. The truck does fine for range if one is traversing like a cybertruck should.

Would I have enjoyed the range extender? Sure, as it would have been not DIY as all the crazy ideas I see here. Would still be able to puyt a Eco Flow in the back and have more.


Tesla needing kickstarter money. Good one for a laugh. Did you really say that?

Yes I did. Glad it entertained you. I don’t think they needed it but why not take it if people are willing to offer it for a niche product that may or may not work out.
Also, I agree with the rest. Planning properly for this is no different than carrying an appropriate amount of gas in an ICE vehicle.

 

[hemiarch]

So you have the cyberrruckco camper? How do you like it? I’m very tempted by it.

 

[Outdoors]

Yes I did. I don’t think they needed it but why not take it if people are willing to offer it for a niche product that may or may not work out.

It was a demand estimator. Putting the word kickstarter just diminishes. Tesla can't just put a checkmark and just say. Hey might ya want it? We might make it. One has no obligation. So we will make it, then everyone says no. It is the same process as ordering A F-350 with some option yet to be made. It might be in the advertising specs, and then doesn't make it to production. Yet because it is Tesla it is some type of failure. That is why the term Kickstarter is kind of disingenuous.

Many automakers offer line items, and then don't produce. Look at them. Most here may not be used to it. They just call you up and say. Option X isn't available on your order for the limited car you want. Would you call that a kickstarter too? Sucks it was post purchase, but there was no obligation to build.

 

[hemiarch]

Fair enough. I was just trying to convey using the word kickstarter that it wasn’t necessarily a commitment for them the way people interpreted it. Tesla doesn’t need my help diminishing its own reputation recently it seems.
I still think they are a fantastic company, I’m just not sure what they are thinking in terms of public image as of late.
Anyway, this isn’t really an issue I feel that strongly about because I honestly never needed the range extender myself.
I am still curious as to your thoughts about the camper if you’re using it.

 

[mongo]

Kludging on an extra battery is not as simple as connecting the red wire to the positive and the black wire to the negative.

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.

What do people not understand about this and why do they feel entitled to things the reservation deposit did not grant?

It not necessary understanding, it's the difference in expectation between buying a $140k truck that gets you there and back versus a $120k truck that doesn't...
Or, based on timing/ selection a $72.5k truck that doesn't.

The truck does fine for range if one is traversing like a cybertruck should.

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.

I think many are just calculating nerds.

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

If you’re towing a trailer, doesn’t that also mean you’re adding a bunch of roof surface area to the rig which can be covered in solar? Let’s think outside the battery box here for a second.
All they would really need to do is produce an input mechanism with adequate specs for plugging a fair amount of solar into the truck while driving.

It's questionable if that works on a daily driving basis. 8ftx32ft trailer = 20m² * 20% * 6 hours * 1kW = 24kWh: 24-48 miles per day additional .
Good for stationary camping though.

 

[hemiarch]

It's questionable if that works on a daily driving basis. 8ftx32ft trailer = 20m² * 20% * 6 hours * 1kW = 24kWh: 24-48 miles per day additional .
Good for stationary camping though.

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.

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