All Seven Alta Patents
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TonyWilliams
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What electrical innovations? The bike is very simple:
1) Panasonic or Sony 18650 cells in a container, like Tesla and other vehicle manufacturers. Tesla is now moving to the Panasonic 2170 cells with an advantage in energy density. Even the cell fuseable link is a Tesla design.
2) Battery Management System that can be purchased from many vendors
3) Chinese built vendor supplied charger
4) Custom built inverter - probably the single real innovative technology in this machine. Yes, it can be built “by anybody”.
5) Vendor supplied motor
6) Wiring harness - very conventional
7) Vendor supplied Hall effect throttle
8) Software to manage throttle
9) Software to manage battery, inverter and motor
10) Vendor supplied display
11) Lights, tail light, license plate light, horn, turn signals, reed switch on side stand
12) Vendor supplied coolant pump
13) Vendor supplied switches (key, horn, high beam, turn signals, kill switch, start switch)
Did I miss anything?
Redwolf
My dog thinks I'm cool
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12) coolant pump...
TonyWilliams
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12) Vendor supplied coolant pump
TonyWilliams
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13) Vendor supplied switches (key, horn, high beam, turn signals, kill switch, start switch)
Some paragraphs from my 2017 technical review. Although I've revised my detailed assessment regarding a few specifics my investigation opened my eyes on just how far electric motor and motor control technology has come in a relative short period of time and it's also absolutely clear that we've just scratched the surface. And it doesn't take a huge corporation with unlimited resources to develop. The future is clear and there's tons of creative people just like us working in small labs everywhere experimenting with and advancing this old tech. The possibility that an individual or small company such as Alta has developed the "next step forward" is very real. It was with this "possibility" in mind that I made the assessment below. While probably not 100% correct the real takeaway is that Alta probably does have some valuable IP hidden somewhere inside our bikes.
From 2017 . . . . . . . .
Alta needed a control system which would allow them to reshape the typical electric motor torque vs speed curve into something much more appropriate for the task. The electronic equivalent of turning a 250 trials bike into a fire breathing 250F with a few key strokes. FOC allows this “reshaping” to happen electronically. However, as with any IC engine, reshaping the torque curve is usually a compromise. To gain in one area means a loss in another. In other words, the “area under the curve” stays the same. If Alta wanted to improve on one major characteristic flaw of the IC engine this would be it!
That’s exactly where I think Alta has changed the rules by successfully designing and implementing a “variable flux memory motor system”. As discussed, a “variable flux memory” motor is one where the flux (magnetic strength) generated by the rotor permanent magnets can actually be controlled by changing the effective magnetization state of the magnets themselves. Wow, that’s a mouthful. However, by doing so I think it made the Redshift a viable option.
To this end, I believe Alta developed a specialized version of FOC which, when combined with a motor rotor incorporating the features explained in the motor section, can force some or all of the rotor magnets to become REVERSABLY demagnetized. Demagnification significantly reduces the performance damaging back EMF inherent with a PM motor, particularly at higher speeds, which otherwise limits the speed range of the motor. In fact, this type of system probably takes the motor from a rated 3000 rpm top speed to the advertised 14,000! That’s almost a 500% (5X) increase! And it’ll still have decent torque at 14 grand to boot. This significantly extended speed range also has a name, “Constant Power”. Since power is torque AND speed dependent this name suggests that as RPMs increase and torque decreases but power stays the same. This is perfect for fast and continuous acceleration all the way to top speed! At lower speeds when back EMF is not an issue, the same magnets can again be fully re-magnetized resulting in the higher(rated) torque production needed to accelerate from a standstill even at the VERY high final drive gearing needed for 60+ mph. It’s the equivalent of starting your 250F in5th gear and still being able to dig a trench out of the gate. Quite an achievement.
But there’s more. I think Alta also figured out a way to physically (rotor) and electronically (FOC) boost slow speed performance above rated torque as well. Again, I think the answer involves combinations of magnets whose magnetizing state has been selectively altered along with the more traditional (although less efficient) phase angle changes to produce a net torque from both magnetic and reluctance interactions that exceeds the maximum value of either one individually. Phase angle is somewhat analogous to ignition/valve timing on an ICE.
With this added capability the FOC system can reshape BOTH ends of the torque/speed curve without excessively relying on the inefficiencies associated with continuous field boosting or weakening. It’s a win –win! Instead, to change magnet states, the FOC system simply needs to supply a onetime high intensity “pulse” of current at just the right time to the right phase. The magnitude and direction (Pos or Neg) of the pulse determines the state (+/-) and magnetic strength of the PMs. At a minimum, I would expect 4 states; 100% mag strength, 50% mag strength, 0% mag strength and -100% mag strength. Pretty sweet if true.
The possible combinations of AC current control along with TWO flux controls (phase angle and PM magnet state) that can satisfy any particular operating condition (load) can get pretty complicated. However, when the requirement is to do so most efficiently is added the possible combinations reduce drastically. On an IC engine, this would be analogous to testing different combinations of ignition and valve timings at various throttle openings and loads and then looking for the combinations that offer the best performance at the best fuel economy. And like IC engines, this is where actual motor dyno work is necessary. By trying all the viable combinations of controls on the motor dyno the best ones for every operating condition can be found and combined into simple lookup tables. This saves the FOC a bunch of computing power and time. Again, not unlike the way timing and fuel injection is done on IC engines.
So, what does the ICE equivalent dyno chart look like after loading the optimized control mapping into the FOC? Well, based on information derived from Alta’s website it appears Alta front loaded the torque curve (constant torque) and then gradually reduces torque as motor RPM increased (constant speed). Frankly, not totally unlike that of an ICE engine but without the torque multiplying benefit of a transmission. In fact, based on data from Alta, if you connected the bumpy torque peaks for each gear of a typical 250F with a smooth fitted curve it would look very similar to the reshaped torque curve for the Redshift. Based on this it’s easy to conclude the Alta is superior on the “paper dyno” as there’s definitely “more area under the power curve”. Plus the Alta exceeds the 250F at every point along the curve! This squares with Alta’s goals to produce an electric bike that felt (throttle response, engine braking, speed, etc) like a typical ICE bike only better. I don’t have any efficiency numbers to quote but I suspect the average is above 90%. Therefore, on paper both power and efficiency are quite remarkable.
My following explanation on how FOC works is much simpler than it really is but it’s adequate enough for the purpose of this paper. FOC works by measuring specific real time motor currents and voltages along with the exact position (rotor angle) and speed of the motor’s rotor. An onboard FOC computer processes this information in a series of relatively complicated algorithms (Forward and Reverse Clark and Park Transformations) resulting in the two previously mentioned simple numerical values representing ACTUAL Torque and Flux. These values are then compared to the DESIRED values (throttle position) and if different will alter the voltages going to each motor phase until the two values match. It’s a closed loop system. This “process” happens literally thousands of time per second making for very precise speed control, even at very low motor rpms. Of course, the FOC computer can’t handle the motor’s high voltages and currents directly so a system for “scaling up” the motor control signals must be incorporated. This process is generically called modulation. In this case, a particular type of modulation known as Space Vector Modulation.
Space Vector Modulation is a type of Pulse Wave Modulation (PWM). It takes the control signals from the FOC systems and converts them into a digital form required by the Inverter to generate the desired high power 3 Phase sinusoidal waveforms needed to power the motor. The conversion is somewhat convoluted to explain but it involves several look-up tables and some fancy formulas/calculations. The speed and complexity of the process dictates that a specialized processor and associated circuitry be used. Again, there are several types of PWM to choose from, but SVM PWM results in lower switching loses and can utilize 100% of the bus voltage where others are around 85%.
Although not exactly new, the basic forms of SVM and FOC typically require quite a few physical interconnects along with the resulting losses in harness pin outs and wiring. I believe Alta has managed to combine many of the critical signals onto a very high data rate CAN network. This would be a relatively significant accomplishment as these kind of signals are typically hardwired due to current CAN (and CAN like) technology limitations. This all gets back to energy efficiency as discussed.
From 2017 . . . . . . . .
Alta needed a control system which would allow them to reshape the typical electric motor torque vs speed curve into something much more appropriate for the task. The electronic equivalent of turning a 250 trials bike into a fire breathing 250F with a few key strokes. FOC allows this “reshaping” to happen electronically. However, as with any IC engine, reshaping the torque curve is usually a compromise. To gain in one area means a loss in another. In other words, the “area under the curve” stays the same. If Alta wanted to improve on one major characteristic flaw of the IC engine this would be it!
That’s exactly where I think Alta has changed the rules by successfully designing and implementing a “variable flux memory motor system”. As discussed, a “variable flux memory” motor is one where the flux (magnetic strength) generated by the rotor permanent magnets can actually be controlled by changing the effective magnetization state of the magnets themselves. Wow, that’s a mouthful. However, by doing so I think it made the Redshift a viable option.
To this end, I believe Alta developed a specialized version of FOC which, when combined with a motor rotor incorporating the features explained in the motor section, can force some or all of the rotor magnets to become REVERSABLY demagnetized. Demagnification significantly reduces the performance damaging back EMF inherent with a PM motor, particularly at higher speeds, which otherwise limits the speed range of the motor. In fact, this type of system probably takes the motor from a rated 3000 rpm top speed to the advertised 14,000! That’s almost a 500% (5X) increase! And it’ll still have decent torque at 14 grand to boot. This significantly extended speed range also has a name, “Constant Power”. Since power is torque AND speed dependent this name suggests that as RPMs increase and torque decreases but power stays the same. This is perfect for fast and continuous acceleration all the way to top speed! At lower speeds when back EMF is not an issue, the same magnets can again be fully re-magnetized resulting in the higher(rated) torque production needed to accelerate from a standstill even at the VERY high final drive gearing needed for 60+ mph. It’s the equivalent of starting your 250F in5th gear and still being able to dig a trench out of the gate. Quite an achievement.
But there’s more. I think Alta also figured out a way to physically (rotor) and electronically (FOC) boost slow speed performance above rated torque as well. Again, I think the answer involves combinations of magnets whose magnetizing state has been selectively altered along with the more traditional (although less efficient) phase angle changes to produce a net torque from both magnetic and reluctance interactions that exceeds the maximum value of either one individually. Phase angle is somewhat analogous to ignition/valve timing on an ICE.
With this added capability the FOC system can reshape BOTH ends of the torque/speed curve without excessively relying on the inefficiencies associated with continuous field boosting or weakening. It’s a win –win! Instead, to change magnet states, the FOC system simply needs to supply a onetime high intensity “pulse” of current at just the right time to the right phase. The magnitude and direction (Pos or Neg) of the pulse determines the state (+/-) and magnetic strength of the PMs. At a minimum, I would expect 4 states; 100% mag strength, 50% mag strength, 0% mag strength and -100% mag strength. Pretty sweet if true.
The possible combinations of AC current control along with TWO flux controls (phase angle and PM magnet state) that can satisfy any particular operating condition (load) can get pretty complicated. However, when the requirement is to do so most efficiently is added the possible combinations reduce drastically. On an IC engine, this would be analogous to testing different combinations of ignition and valve timings at various throttle openings and loads and then looking for the combinations that offer the best performance at the best fuel economy. And like IC engines, this is where actual motor dyno work is necessary. By trying all the viable combinations of controls on the motor dyno the best ones for every operating condition can be found and combined into simple lookup tables. This saves the FOC a bunch of computing power and time. Again, not unlike the way timing and fuel injection is done on IC engines.
So, what does the ICE equivalent dyno chart look like after loading the optimized control mapping into the FOC? Well, based on information derived from Alta’s website it appears Alta front loaded the torque curve (constant torque) and then gradually reduces torque as motor RPM increased (constant speed). Frankly, not totally unlike that of an ICE engine but without the torque multiplying benefit of a transmission. In fact, based on data from Alta, if you connected the bumpy torque peaks for each gear of a typical 250F with a smooth fitted curve it would look very similar to the reshaped torque curve for the Redshift. Based on this it’s easy to conclude the Alta is superior on the “paper dyno” as there’s definitely “more area under the power curve”. Plus the Alta exceeds the 250F at every point along the curve! This squares with Alta’s goals to produce an electric bike that felt (throttle response, engine braking, speed, etc) like a typical ICE bike only better. I don’t have any efficiency numbers to quote but I suspect the average is above 90%. Therefore, on paper both power and efficiency are quite remarkable.
My following explanation on how FOC works is much simpler than it really is but it’s adequate enough for the purpose of this paper. FOC works by measuring specific real time motor currents and voltages along with the exact position (rotor angle) and speed of the motor’s rotor. An onboard FOC computer processes this information in a series of relatively complicated algorithms (Forward and Reverse Clark and Park Transformations) resulting in the two previously mentioned simple numerical values representing ACTUAL Torque and Flux. These values are then compared to the DESIRED values (throttle position) and if different will alter the voltages going to each motor phase until the two values match. It’s a closed loop system. This “process” happens literally thousands of time per second making for very precise speed control, even at very low motor rpms. Of course, the FOC computer can’t handle the motor’s high voltages and currents directly so a system for “scaling up” the motor control signals must be incorporated. This process is generically called modulation. In this case, a particular type of modulation known as Space Vector Modulation.
Space Vector Modulation is a type of Pulse Wave Modulation (PWM). It takes the control signals from the FOC systems and converts them into a digital form required by the Inverter to generate the desired high power 3 Phase sinusoidal waveforms needed to power the motor. The conversion is somewhat convoluted to explain but it involves several look-up tables and some fancy formulas/calculations. The speed and complexity of the process dictates that a specialized processor and associated circuitry be used. Again, there are several types of PWM to choose from, but SVM PWM results in lower switching loses and can utilize 100% of the bus voltage where others are around 85%.
Although not exactly new, the basic forms of SVM and FOC typically require quite a few physical interconnects along with the resulting losses in harness pin outs and wiring. I believe Alta has managed to combine many of the critical signals onto a very high data rate CAN network. This would be a relatively significant accomplishment as these kind of signals are typically hardwired due to current CAN (and CAN like) technology limitations. This all gets back to energy efficiency as discussed.
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That's what I kept telling you guys. That capacitor on top of the battery is a Flux Capacitor!
Butch
Poseur
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Awesome thread.
You guys are a bunch of geeks. I include myself, I suppose.
You guys are a bunch of geeks. I include myself, I suppose.
ElectricMoto
Well-known member
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Tony is correct in that "World-changing" Patents on a motorcycle even if they are electric is hard to obtain. As a Designer / Engineer I would say that Patents are mostly for the Investors as they have no understanding that there are multiple ways of designing something obtaining the same functions. Yes the Alta bike is very much "Advanced Brackets" between vendor-supplied components, however building a complete functional product isn't as easy at may seem (trust me I have done this) There is also a reason that Car manufacturers are very afraid of new electric vehicles as they've spent all their brain trust and money on building combustion engines hence BMW ( Bayerische Motor Werken ) engine tech is what has separated them from the others ( ok production and build quality as well) so what do you do when a Washing Machine company ( e.g. BOSCH) is better than you on building a "Drive train" ..., U shit yourself ,THIS is the reason they have badmouthed EV's for so long.
TonyWilliams
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You could probably do the first 90% real easy. It's the next 90% that always gets you.
leeo45
Geezer in denial
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For archive purposes, all seven detailed patent filings are now posted over in the Resource section.
AoF RESOURCES
AoF RESOURCES
ElectricMoto
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Remember we had 287 items on our BOM (Bill of Materials) and with 286 items (99.65%) good parts in stock still results in no products out the door
TonyWilliams
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Yep... I build shit. It’s exactly that, plus a bazillion dollars tied up.
TonyWilliams
User asked to be "deleted"
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I can do better than that with my perpetual motion machine. Infinity and beyond!!!
Honcho
Well-known member
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Hi all,
I know I've been mum in the forums lately and there are much more pressing things that everyone would like me to comment on... alas I *still* cannot. So in the meantime, I'll chime in here because I can.
I love all the effort to dig in and try to understand what we did and didn't do, and it is a nearly impossible task to get it all right from the outside in... so it's not surprising that the speculation is pretty far off. Maybe the two biggest misunderstandings are:
1) ownership of architecture vs design vs development vs manufacturing vs supply vs assembly, and especially in the understanding of what it takes to reliably and repeatably manufacture any of these systems.
2) the use of conventional (therefore relatively cheap, available, and of known properties) materials implemented very cleverly
Everyone thinks they're going to find some magic goo inside... some alien unobtanium that enables things never thought possible. That's the stuff that dies in laboratories. Good engineering finds clever and elegant ways to do things better with less material, less processes, and at a lower cost. It is hundreds of small ideas and careful implementation of tech that produces a reliable, robust, (relatively) affordable commercial product. I know that's not sexy, but we were never in the business of producing shiny prototypes that ran for an hour for the cameras and never made it to customers.
With that said...
The patent office wasn't as liberal with us as with some others, so we chose to maintain much of our technology as trade secret - especially the industrialized processes that enable us to build our pack. As I wrote Mark in an email, do not confuse very elegant engineering with simplicity or a lack of engineering. The battery pack is quite unique and very very difficult to replicate. There are several reasons why we have (had?) the highest energy density in transportation, all while maintaining anti-propogation resistance at and above automotive standards. If you try to pack high energy (3 Ah+) 18650 cells into a pack as closely as we have, and you don't do the things we did, you will have a very very dangerous pack. We were the first to be able to achieve permanent interconnects that allowed us to orient all of the cells in the same direction. We were the first to thermally couple to the base of the cell. These things are not trivial - many had given up on the approaches that we were able to implement repeatably and reliably. We had to build our own battery manufacturing plant in Brisbane to make the Redshift pack possible. Even though this ultimately is Alta's biggest competitive advantage, if I third party had been capable of building it, we would not have made that multi-year and multi-million dollar investment.
I'll address the others below, in line.
The reason I couldn't keep my mouth shut is we actually DID take the clean sheet approach, where nearly every other company in the space was more of a systems integrator. There is literally not a single sub-system from the rear axle to the headstock that wasn't a ground-up Alta design and development. Yes, we use third party components (e.g. chips, pumps, springs), but that is so very far from using third party subsystems (e.g. controllers, motors). There is not a line of code on the bike that wasn't written or rewritten by an Alta engineer.
Thanks for letting me vent. I look forward to talking about more important things sometime soon. Believe me, the wait is as excruciating for me as it is for all of you, and I'm really sorry that all of our customers, dealers, vendors have to go through this with us.
I know I've been mum in the forums lately and there are much more pressing things that everyone would like me to comment on... alas I *still* cannot. So in the meantime, I'll chime in here because I can.
I love all the effort to dig in and try to understand what we did and didn't do, and it is a nearly impossible task to get it all right from the outside in... so it's not surprising that the speculation is pretty far off. Maybe the two biggest misunderstandings are:
1) ownership of architecture vs design vs development vs manufacturing vs supply vs assembly, and especially in the understanding of what it takes to reliably and repeatably manufacture any of these systems.
2) the use of conventional (therefore relatively cheap, available, and of known properties) materials implemented very cleverly
Everyone thinks they're going to find some magic goo inside... some alien unobtanium that enables things never thought possible. That's the stuff that dies in laboratories. Good engineering finds clever and elegant ways to do things better with less material, less processes, and at a lower cost. It is hundreds of small ideas and careful implementation of tech that produces a reliable, robust, (relatively) affordable commercial product. I know that's not sexy, but we were never in the business of producing shiny prototypes that ran for an hour for the cameras and never made it to customers.
With that said...
The patent office wasn't as liberal with us as with some others, so we chose to maintain much of our technology as trade secret - especially the industrialized processes that enable us to build our pack. As I wrote Mark in an email, do not confuse very elegant engineering with simplicity or a lack of engineering. The battery pack is quite unique and very very difficult to replicate. There are several reasons why we have (had?) the highest energy density in transportation, all while maintaining anti-propogation resistance at and above automotive standards. If you try to pack high energy (3 Ah+) 18650 cells into a pack as closely as we have, and you don't do the things we did, you will have a very very dangerous pack. We were the first to be able to achieve permanent interconnects that allowed us to orient all of the cells in the same direction. We were the first to thermally couple to the base of the cell. These things are not trivial - many had given up on the approaches that we were able to implement repeatably and reliably. We had to build our own battery manufacturing plant in Brisbane to make the Redshift pack possible. Even though this ultimately is Alta's biggest competitive advantage, if I third party had been capable of building it, we would not have made that multi-year and multi-million dollar investment.
I'll address the others below, in line.
The reason I couldn't keep my mouth shut is we actually DID take the clean sheet approach, where nearly every other company in the space was more of a systems integrator. There is literally not a single sub-system from the rear axle to the headstock that wasn't a ground-up Alta design and development. Yes, we use third party components (e.g. chips, pumps, springs), but that is so very far from using third party subsystems (e.g. controllers, motors). There is not a line of code on the bike that wasn't written or rewritten by an Alta engineer.
Thanks for letting me vent. I look forward to talking about more important things sometime soon. Believe me, the wait is as excruciating for me as it is for all of you, and I'm really sorry that all of our customers, dealers, vendors have to go through this with us.
leeo45
Geezer in denial
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Honcho - Very much appreciate the insight from the inside out. Also great to know that you and some of the other ALTA gurus are still around here.
Rayivers - The resulting products are exactly why I never pulled the trigger to buy a Zero and why I ordered an ALTA as soon as the EXR was announced.
Wow, Honcho's comments got me thinking . . . . . . that means late nights researching for at least a week! LOL.
Thermally coupling the negative cell ends (the one area of a 18650 cell that's can support halfway decent heat transfer, relatively speaking) while maintaining electrical isolation is a tough nut to crack. See my comments here; Battery Pack Disassembled (Frustrating Weekend). Thinking out loud, if the cell's emergency burst vent is compromised to obtain good thermal contact area (or it doesn't even incorporate such a feature) some other form of cell side rupture prevention is required. Or is it? Maybe the geometry of the composite support structure is one key? The "venting shafts" I mentioned in the other forum link could also doubles as a stress riser, essentially a "designed in" weak spot where the side of the cell's canister is forced to fail in the event of an overpressure situation. If so designed and verified, it would allow for maximum possible thermal dissipation where it's most effective and efficient. In addition, if said failure occurred over the entire length of the vent shaft over a finite amount of time the corresponding escaping gas velocity would be much slower and more controlled, both very desirable in such a situation to prevent collateral damage and potential TR. I'd consider this to be clever as opposed to some magic goo.
Traditional rationale regarding the "same side" cell interconnects has always been the additional circuit resistance and associated heating that it produces. Alta either debunked this through analysis/test or figured out ways to mitigate it. Again. more food for thought.
Thermally coupling the negative cell ends (the one area of a 18650 cell that's can support halfway decent heat transfer, relatively speaking) while maintaining electrical isolation is a tough nut to crack. See my comments here; Battery Pack Disassembled (Frustrating Weekend). Thinking out loud, if the cell's emergency burst vent is compromised to obtain good thermal contact area (or it doesn't even incorporate such a feature) some other form of cell side rupture prevention is required. Or is it? Maybe the geometry of the composite support structure is one key? The "venting shafts" I mentioned in the other forum link could also doubles as a stress riser, essentially a "designed in" weak spot where the side of the cell's canister is forced to fail in the event of an overpressure situation. If so designed and verified, it would allow for maximum possible thermal dissipation where it's most effective and efficient. In addition, if said failure occurred over the entire length of the vent shaft over a finite amount of time the corresponding escaping gas velocity would be much slower and more controlled, both very desirable in such a situation to prevent collateral damage and potential TR. I'd consider this to be clever as opposed to some magic goo.
Traditional rationale regarding the "same side" cell interconnects has always been the additional circuit resistance and associated heating that it produces. Alta either debunked this through analysis/test or figured out ways to mitigate it. Again. more food for thought.
Silent But Dirty
Alta North
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Check out this article https://chargedevs.com/features/alt...ric-dirt-bike-has-world-class-energy-density/
Part way through there is some talk of the specific material they use for thermal conductivity. I can't find it again, but I remember reading somewhere that the pack had been tested to remain safe even with as many as 3 cells experiencing simultaneously thermal runaway.
Part way through there is some talk of the specific material they use for thermal conductivity. I can't find it again, but I remember reading somewhere that the pack had been tested to remain safe even with as many as 3 cells experiencing simultaneously thermal runaway.
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