No, because they do different things. At low and medium speeds, the vesc acts a bit like a DC-DC converter: The switching of the mosfets, combined with the inductance of the motor, effectively step down the battery voltage to whatever is required at a given time. It is entirely possible (in fact, incredibly common!) to have more current flowing through the motor, than is flowing from your battery.
That does not mean thereās some free energy, overunity bullshit going on. The voltage is proportionally lower, you are getting the same number of watts. This is why you see people with, say, 40 battery amps and 80 motor amps. At low speed, under acceleration, the vesc will pull up to 40 amps from the battery, and deliver up to 80 amps to the motor, simultaneously.
TLDR; Battery amps =/= motor amps. They are not the same. They are not directly related.
the upside of setting the motor max higher than the battery max is you have more torque available at low to mid speed, without exceeding the battery max
the downside of setting motor max higher than the battery max is the motor max setting sets the motor current and torque at full throttle, but at the higher speeds it takes almost an equal # of battery amps to supply the full motor max, but if you set the battery max lower than the motor max, the result is at higher speeds, you lose some higher end throttle range, and this effect becomes more pronounced the higher you set the motor max above the battery max
see the circled area of the chart below with 100a motor / 60a bat vs 60a motor / 60a bat
But inside the enclosure to take up space I use any closed cell packing foam from boxes that come in the mail. Pack as much of that shit inside as you can. I usually cut it into strips averaging 1cm x 5cm -ish and stuff them everywhere I can
prob noob question, but arenāt both 30Q and 40T both Liion? when you say go Lipo for more power, which cells do you mean? just looked up difference between lipo and liion and all i get is lipo is the newer technology and has smaller form factor and Liion carry more energy density but larger cells. sorry if asnwer is obvious, new to this stuff.
Yes Li-Ion
30Q are 18650ās (size)
And 40T 21700 (size)
40T are 40% bigger I think from memory.
This depends.
Lipo are know to have less sag then li ion but once they are empty they die.
Example;
So going up a steep hill all li ions will experience sag. Basically they can only give so much power for a given time before they need to limit it to avoid over heating and such.
But once you start using it normally again (the big hill has ended) the li ion will be back to normal and they do this all the way until a very low capacity.
Lipo tend not to have much sag until a certain voltage (much higher than li ions) then they are pretty useless and need to be charged.
Lipo are often used more in MTB but if you need range then li ion is better overall.
Li ion have 1/4 to double the charge cycles of lipos. It depends basically on what you want.
I donāt think Lipo are worth it personally. They are heavier compared to the same energy density for a Li ion.
Used right they can be great. Look at @Arzamenable Xpham build. He uses Tattu lipos.
I personally have never tried Lipo apart from a evolve board but that does not count coz they suck ass.
thanks for clarifing that. i wonāt go lipo i donāt think
iāve use the esk8 calculator to try and work out the different ranges iād get on the 30Q and 40T cells respectively. im at the research stage so havenāt bought hardly anything yet and so donāt know the data for the drive train section, but so far are these readings correct/have i filled in the info right??
I think I said it before but lipos really good for race boards or something light with low range. As soon as you want to get more than 10-12km range I would always swap to LiIon.
They are more light than, means more range for same weight and cheaper in the long term. Lipos usually do not hold on more than one year if you use them regularly.
LiIon is as well easier to handle. No need for storage charge etc.
If you do not want to build your own pack than ok, lipos are a good alternative, but in times of no solder packs and good battery pack vendors that shouldnāt be an issue to get a LiIon pack without to build it by your own.
One thing to add to the lipo explanation before.
Lipos have a different discharge curve. Means most time of the discharge you stay in the 4.2-3.7V area which as well results in the fact that you can longer drive faster. But as soon as you drop below 3.5-3.6V your cells do not hold a lot of charge anymore. If you do not choose your cut off voltage properly itās very easy to over discharge your pack and with it damage the cells.
i was wondering about damaging cells. had read about someone killing a whole battery because they let the discharge drop below a certain a level. would i have been reading only about lipos in that case? ā¦as in do Liions not suffer from damage if you run them below a certain discharge range?
If you discharge LiIon below 2.5V they take damage as well.
Lipos i wouldnāt discharge below 3.4V.
I had this one time accidentally happening and even with a low load on the bench I had some cells in the pack drop down to 2.7V super fast.
Luckily I noticed that fast enough and recharge them up to storage voltage again, but that did cost me for sure some charge cycles live span
