What Alta REALLY needs to release is the software for reading the realtime and logged data from various controllers in the system. If you've ever used one of those simple "OBD2" (Onboard Diagnostics ver 2) interfaces to help troubleshoot your car's emissions systems you'll know exactly what I'm talking about. With access to data such as instantaneous current and voltage, motor rpm, etc, it wouldn't be difficult to write a simple script to determine torque and HP. Essentially, using the realtime or logged data as a "virtual" dyno! It would be analogous to measuring ICE parameters using OBD2 access such as airflow, injector time, and rpm to determine torque and HP but without the totally chaotic variable known as combustion to screw up the calculations.
In regards to this particular thread, having access to the battery management system (BMS) controller where individual cell data is kept would be truly eye-opening. You'd be able to see individual or groups of cell temperatures, voltages, estimated capacities, current status, etc, under both running and charging conditions. This data alone would help one understand how Alta programmed the system.
The next even bigger ask would be a communication system with WRITE authority for certain parameters. Alta, like any manufacture, must be very conservative in many design aspects for reliability and liability reasons. Since this tread is about battery packs, Alta must be concerned about individual and collective cell life and safety. Li-Ion cells such as the 18650 are like IC engines in many ways. There are MANY parameters under Alta's control even after the specific chemistry and construction are selected and the cells procured from the vendor. Lets call this particular cell a stock 250F engine. That stock cell was designed by the manufacture with certain performance and reliability claims based on specific operating conditions. For example, like an IC engine with a rev limiter set at 12,000. Want more performance, no problem, just operate the cell outside the manufactures recommended (and warranted) recommended operating conditions. Like re-programing the 250F rev limit to 14,000 rpm!
However, just like the ICE example, exceeding recommended operating conditions has risks, like a blown motor! The biggest risks for any individual cell is internal damage which leads to degraded capacity (cell life) or worse yet, thermal runaway. If you've never seen a battery pack made of dozens of 18650 cells in thermal runaway just google it, it's not a pretty sight. Cell life, while not as dramatic, is a major concern for any EV owner not looking to prematurely spend big bucks on a new pack.
But that doesn't stop tuners from modifying IC engines for "reasonable" performance improvements and it doesn't stop Alta from making similar "reasonable" modifications to the cells in their pack either. This process is always ongoing as Alta gains more user data and at each new cell design iteration. They want to push the envelop only so much, release it and see how it performs in real world conditions. That's why getting the latest software update is always important.
What parameters are typically tweaked? The BMS system controls most of these and very simply they can be divided into two categories, charging and running. When charging the BMS controls the max voltage each cell can obtain. The nominal voltage for a 18650 is around 3.6v, but the charge cutoff voltage is significantly more, 4.0-4.2v. Pushing the voltage higher means more capacity (like a bigger gas tank on the 250F), up to a point! After that all you get is a bunch of heat with the possibility of permanently damaging the cell. In any event, anytime you exceed the cell mfg recommended max charge voltage you run the risk of longterm degradation. Another charging related parameter would be max charging current. Increasing this results in quicker charge times but again you run the risk of longterm degradation.
An example of some running parameters would be cell maximum discharge rate and cell temp. Higher discharge rates is like a ported head on the 250F, more airflow. Discharge rates are typically tied to safe cell temperatures. Higher current rates typically mean higher cell temperatures just like higher HP means higher combustion temps in an ICE. High cell temperatures are associated with cell thermal runaway, definitely not a condition you want. Cell discharge rates and temperatures are closely monitored as you ride and the system will automatically limit power if these parameters exceed programmed limits. Continual operation at these upper limits also leads to the risk of longterm degradation. If you are the type of rider who's always on the verge of thermal intervention I suspect your pack will expire before someone who does not. Remember, the "industry standard" for needing a new pack is around 80% of the original capacity. It doesn't mean your bike wont work, it just means you'll only have 80% of the original range/performance. How quickly the pack dies (in charge cycles) after reaching the 80% point is another concern.
Back to the point, although Alta may not want to risk pushing the pack harder I think the owner should have the ultimate decision. With WRITE access we'd have the ability to modify certain performance parameters just like we have today with our ICE bikes. This has implications far beyond the battery pack; examples include user defined throttle response, performance maps, engine braking, etc. All done using a simple app on your phone. If pushed too hard our IC engines blow up. The risk is the same with our electric bikes. However, in the case of thermal runaway the expression "blow up" is an under statement!
In regards to this particular thread, having access to the battery management system (BMS) controller where individual cell data is kept would be truly eye-opening. You'd be able to see individual or groups of cell temperatures, voltages, estimated capacities, current status, etc, under both running and charging conditions. This data alone would help one understand how Alta programmed the system.
The next even bigger ask would be a communication system with WRITE authority for certain parameters. Alta, like any manufacture, must be very conservative in many design aspects for reliability and liability reasons. Since this tread is about battery packs, Alta must be concerned about individual and collective cell life and safety. Li-Ion cells such as the 18650 are like IC engines in many ways. There are MANY parameters under Alta's control even after the specific chemistry and construction are selected and the cells procured from the vendor. Lets call this particular cell a stock 250F engine. That stock cell was designed by the manufacture with certain performance and reliability claims based on specific operating conditions. For example, like an IC engine with a rev limiter set at 12,000. Want more performance, no problem, just operate the cell outside the manufactures recommended (and warranted) recommended operating conditions. Like re-programing the 250F rev limit to 14,000 rpm!
However, just like the ICE example, exceeding recommended operating conditions has risks, like a blown motor! The biggest risks for any individual cell is internal damage which leads to degraded capacity (cell life) or worse yet, thermal runaway. If you've never seen a battery pack made of dozens of 18650 cells in thermal runaway just google it, it's not a pretty sight. Cell life, while not as dramatic, is a major concern for any EV owner not looking to prematurely spend big bucks on a new pack.
But that doesn't stop tuners from modifying IC engines for "reasonable" performance improvements and it doesn't stop Alta from making similar "reasonable" modifications to the cells in their pack either. This process is always ongoing as Alta gains more user data and at each new cell design iteration. They want to push the envelop only so much, release it and see how it performs in real world conditions. That's why getting the latest software update is always important.
What parameters are typically tweaked? The BMS system controls most of these and very simply they can be divided into two categories, charging and running. When charging the BMS controls the max voltage each cell can obtain. The nominal voltage for a 18650 is around 3.6v, but the charge cutoff voltage is significantly more, 4.0-4.2v. Pushing the voltage higher means more capacity (like a bigger gas tank on the 250F), up to a point! After that all you get is a bunch of heat with the possibility of permanently damaging the cell. In any event, anytime you exceed the cell mfg recommended max charge voltage you run the risk of longterm degradation. Another charging related parameter would be max charging current. Increasing this results in quicker charge times but again you run the risk of longterm degradation.
An example of some running parameters would be cell maximum discharge rate and cell temp. Higher discharge rates is like a ported head on the 250F, more airflow. Discharge rates are typically tied to safe cell temperatures. Higher current rates typically mean higher cell temperatures just like higher HP means higher combustion temps in an ICE. High cell temperatures are associated with cell thermal runaway, definitely not a condition you want. Cell discharge rates and temperatures are closely monitored as you ride and the system will automatically limit power if these parameters exceed programmed limits. Continual operation at these upper limits also leads to the risk of longterm degradation. If you are the type of rider who's always on the verge of thermal intervention I suspect your pack will expire before someone who does not. Remember, the "industry standard" for needing a new pack is around 80% of the original capacity. It doesn't mean your bike wont work, it just means you'll only have 80% of the original range/performance. How quickly the pack dies (in charge cycles) after reaching the 80% point is another concern.
Back to the point, although Alta may not want to risk pushing the pack harder I think the owner should have the ultimate decision. With WRITE access we'd have the ability to modify certain performance parameters just like we have today with our ICE bikes. This has implications far beyond the battery pack; examples include user defined throttle response, performance maps, engine braking, etc. All done using a simple app on your phone. If pushed too hard our IC engines blow up. The risk is the same with our electric bikes. However, in the case of thermal runaway the expression "blow up" is an under statement!
