Ahhh…I strongly disagree. A good pack design considers a large number of specific situations and then the builder decides whether to take those into account or not when designing the pack.
High/low temperatures, degree of water ingress, charge voltage and current, discharge voltage and current, vibration/shock magnitudes, frequency, and directions, ease of repair, etc., can all be considered.
What causes the changes to any of those things are irrelevant though. I don’t care what causes a temperature change or a particular physical shock. I don’t care why the voltage at the charge port is too high. I only care what is happening to the pack itself and whether I want to do what’s necessary for the pack to survive that particular abuse.
I agree though that human error, i.e., pack design/assembly that was done poorly or that did not anticipate the conditions the pack would actually operate in, is by far the more common situation. Crappy BMS’ and crappy harnesses are sold though, along with other things that can cause cell failure.
Minimizing the possible human error just requires a builder who cares and who has learned enough. Not always easy to do though.
Heat is indeed the enemy and we should always consider pack temperature. But for many packs, and many builders, the temperatures the cells will reach without any type of cooling just isn’t a concern. Either because the cells never get too hot, the builder just doesn’t care about cycle life, or the builder isn’t even aware that the pack might get too hot.
Heat-sinking a pack is very, very difficult and expensive. Most esk8 packs just don’t need it though IMO due to them being pulsed most of the time rather than run continuously (for most riders).
You can easily use a heat spreader in a pack, some sort of material to spread the heat more evenly, but getting the heat out of the pack (having a heat sink) is tough to do. The pack needs to be thermally coupled to the outside of the enclosure and that is not easy to do properly. As you mentioned, water ingress is an issue along with the amount of effort needed to get the heat from all the cells fairly equally to the outside of the enclosure.
That costs a lot of money and takes up a lot of room. It is often easier to just add more cells in parallel and/or limit the battery current in the ESC.
Just gonna jump in here and say that I build esk8 and other PEV batteries for a living, and every build I make is tailored for a client’s specific use case.
In my opinion if anyone is building batteries for someone without adequately understanding their use case, then they are not doing their due diligence and are potentially making an unsafe pack.
The range of applications for lithium batteries are so diverse that it’s impossible to say if one pack vs another will be safe without knowing the use case.
Take, for example, powerwall packs vs esk8 packs. A powerwall can often get away with no fish paper, no vibration isolating, sharp corners on nickel strips, etc., simply because they dont move during normal use. Where as our esk8 packs have to be built to a very high safety standard, taking into account high-vibrations and micro/macro flexing.
A battery which might be totally safe sitting in your garage storing the excess power from your solar panels would be a fireball waiting to happen if you were to put it in an esk8.
/rant
Anyway, thats all I have to contribute. Everything else, Mooch said better haha. Listen to him, he is smarter than 99% of folks on this forum when it comes to batteries.
Thanks for the reply. I didn’t realize that the Trampa is a single controller. On the site it sounds like Bejnamin Vedder helped build the thing:
“TRAMPA BOARDS LTD has teamed up with the internationally renowned ‘YODA of electronics’ (Benjamin Vedder) to bring to the world the most advance electronic speed controller ever to be produced!”
Now that I’m looking at it closer it looks like the Makerx-tech GO-FOC HI300/HV200 75V/100V 300A/200A ESC is also a single motor ESC, is that correct?
I need a dual motor ESC as my scooter has two motors. Is the Stormcore 100D the only VESC ESC available that will handle dual 1,600 watt continuous motors on a 72 volt system?
100D can handle upto 84v (18S) safely, so I would expect it to run fine with just 72v. unless u HAVE to run it at 72v, or else spintend ubox is also a great option, but it can only do 75v (<80v for peak)
Make sure you know what battery you have, because often folks use “xxV system” to not mean the actual max system voltage.
The best way is to say “20S” or “17S” — both of those can be called “a 72V system” whatever that even means. Easiest way is often to look at the charger, it will frequently have the real max voltage listed on it, and not just an average estimated number.
I have two sensored motors but I really don’t need them, I’ve programmed them to run sensorless…
Should I just leave the sensors disconnected from the vesc or should I desolder them off the motor’s mainboard?
unplug and hide away, keeping them soldered doesn’t really change anything except if u want to sell those motors in the future and the buyer might need those sensors
Any thoughts on how to get the belt to stop walking? From my understanding this is caused due to a misalignment of either the motor mount or maybe even the set screws torque?
For reference I’m using matrix II trucks.
The pulleys I have don’t have a flange so the belt will walk all the way to the wheel and if I carve the belt will pop off the motor pulley.
yes this also, i almost forgot
