Yeah, I thought of that but I don’r really feel like rewiring my batteries. AND my vesc has been giving me shit by cutting out due to overheating, so more amps won’t be an improvement. I can always run my zippy’s.
I think if you want to keep the 12s format without parallel setup ( doesnt fit anyway on rosti mepal), you should try get those big capacitors and have them mounted. That should help reduces battery stress.
Otherwise get the graphene battery and test them. It has 45c or 65c rating which is great to reduce battery stress when only 1 pack is used.
You can load 4 3s 4000mah 65c in that box. Thats the best Ive seen by far with turnigy graphene setup inside rosti box.
I dont’t believe capacitors are of any use here. Based on what ?
why wouldn’t Caps be of any use? I reckon caps are a great idea.
People have had similar experiences like yours when they compare Zippys and Multistars in racing quadcopters. As other people have said, they last long and thats about it.
Its known that caps can help reduce cogging or stress during short burst discharge. This already help improve battery life during starting standstill or small acceleration.
It could also be that the low voltage cut off was too low everytime. But batteries die quick is always because of too much stress. This possibly have an impact to your vesc heating up. Strange that my esc doesnt even heatup while you’re with vesc+ heatsink have heat issue. Theres something wrong somewhere.
Please elaborate. How exactly will a capacitor help to overcome limitations of batteries not able to cope with current draw ? I’m curious.
Yeah right. Please allow me to serously doubt that statement. Please calculate for yourself how many amps a 2200uF cap can produce when discharged over an inducance like a brushless motor and report back. Let’s not have newbies reading this thread get the wrong idea. Capacitors over the battery leads are there to smooth out spikes in the voltage due to high frequency switching, not to provide amps when the battery can’t. If someone can prove the opposite using the laws of physics, please do and I’ll adjust my opinion.
Don’t they have something for car amps that help with the sag in voltage when they crank up the music? Would something like that work?
LOL yeah @Michaelinvegas they are called capacitors.
@trbt555 its not the caps alone, but the caps in conjunction with the batteries. caps can discharge quite a lot of amps in a short time and then charge back up just as fast, this is why they are useful. a cap by itself will run high current for like a split second. so no it physically cant run the motor alone, but when a battery is connected in parallel across the caps the battery can recharge the cap with as much current as the battery can provide.
it is only a short burst of current, but it does help.
do you know why a cap helps with ripple? because it can soak up high current spikes very quickly. (you know the arks when you hook them up?) they also do the opposite. you would be pretty naive to think that caps could be connected in parallel with a battery and not have some of the energy sucked out of them when the motor draws it.
I like to call them thingy-whatchamacallits
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Hi Tom you’re the physics man, theres no doubt that the caps wont help much within current draw as current is provided by the batteries anyway. But I meant int he previous comments was the surges, especially during startup. It smoothen out the power draw. I personally use 10000uF caps in addition from the VESC caps and or esc caps. Theres huge spark when connected without antispark.
Thats why I recommend to add parallel connections to the mutistar batteries. You can try and compare them if it works better or not compared to the all series connections.
I don’t want to be the wise ass here but as a scientifically educated person I feel I can sometimes help people understand how things work and why they work or don’t work. There’s no hocus-pocus involved.
Assume you have approx. 2200uF in caps in parallel over your battery leads, which is a typical setup in a lot of cases. Now let’s consider a fully charged 12S system: when charged at 50V, these caps can store 2.75 Joules of energy, you can look up the equation if you like. Suppose you want to accelerate uphill and your weaksauce-filled-Multistar-pack voltage sags to 40V, your caps will discharge 0.99 Joules of energy. Let’s say the voltage sag takes only one second: 0.99 Joules expended over 1 second corresponds to 0.99W of power (Power is Energy over Time) available to your system.
At 40V that equates to a whopping 25mA additional current during that ONE second.
Call me old-fashioned but that just won’t cut it.
So: I agree that caps help smooth out voltage ripple (which is in the millisecond range) but I stand firmly by my statement that they will NOT help with a battery that can’t cope, and we shouldn’t be leading people to believe so either.
(EDIT: thanks to @DerBrecher for pointing out a small error in the energy calculation which is of course quadratically related to voltage)
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Another thought: if you have room for a giant cap, then you have room for a longer cell, and longer cells have more amps. Assuming you’re running prismatics, which is what we’re talking when we say zippys and multistars.
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Caps help with surges only very small, so only during those initial acceleration. It has nothing to do when you already hill climbing for more than lets say 1 second. It all goes back to the batteries performance.
By further eliminating the surges, it should help expand battery life (not significant, but trying to rule out the options to fail faster).
The main problem is that you don’t have enough C rating / discharge capability. It stress too much your battery. You could try use those 45c / 65c rating lipo. Even if you don’t draw that much current as what the lipo could deliver, by not having it discharge near 100% / max rating, it would help alot with the life cycle. This is one of a few reasons why I want to get the graphene. I could do 12s setup but still have the power burst. High discharge capability boost the startup like crazy in my point of view.
Yeah, my caps will cover that initial 25mA surge the first second I accelerate. That really makes a difference 
Anyways, my Multistars are rated 10C, which corresponds to 52A continuous current draw capacity. I’ll be nice and subtract 30% CSI (Chinese Spec Inflation), which gives me 36A continuous. According to my power meter my peak current draw is always less than 30A and still the Multistars don’t seem to like it.
Mind you, there’s no tell-tale puffing, just diminished Ah capacity and wonky cell voltages.
Well, Today I made some test runs
I have multistar 8Ah 6s2p and a 213kv motor (max 10s @ 60A). So i have set in the vesc Option Motor max 60A, battery max 80A and watched the live data with my Smartphone. It always stays at max 60A, because of the Motor max setting -.- but Hey, 60A comes from ~25A is not so good. They are very slow but can reach topspeed and last quite long.
My new Motor did arrive today. I need to change the Motors and retest it with 12S. At least the multistar batteries are well… They are a bit slower compared to zippys. But they are lasting very long : about 20 km.
Is it normal that it will always stay at about 22 Volt shown in the Screenshot (63,7V=22,2)? Fully charged they are at 64,2=25,2V