Regular 4.12 ESC and mini ESC4.20 comparison diagram.
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Don’t worry about the capacitor of mini ESC4.20, all works fine after testing.
In test lab conditions? 
It works even without them but there is reason why there is such capacitance in there…
Actually, we test it in the road, we circuit optimization for the mini ESC4.20, that the reason we can use his short capacitor. 
like I said u can connect no capacitor it will work but not good enough… Plus it pointless to argue with PR agent…
EDIT: those capacitors will not have enough capacitance to clear out current ripples and absorb voltage spikes and will probably end up blowing DRV… I would be careful with braking on these ones.
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@BarbaraZ Why is the flipsky VESC build with MOSFETs that have significantly worse cooling specs that the original 4.12 VESC ? The Rds(on) is twice larger with the FESC 6.6 than with the 4.12 VESC. The Rjunction-case is three times better with the 4.12 MOSFET. Both indicates that the flipsky 6.6 MOSFET (which are the same than the 4.20 ones) cooling specs are well behind the the specs of the original 4.12 VESC.
What was the reason for this choice (except for the price which is half for these new MOSFETs) ?
Furthermore if you compare it with the reference VESC6 with directFET, the differences will be even larger !
(This is a better place to ask these questions than in the groupbuy thread. I removed the other message).
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Price I’m sure is a large part of it. I haven’t looked at the gate charge difference on these, but an important point that a lot of people forget is that losses are not only dependent on the Rds_on. Switching losses can in some cases be much larger than Ohmic losses. I’m not sure if they’ve done their homework on this, but I have a pair of FSESC6.6’s sitting in my mailbox waiting for me and I plan to do some testing to see how bad it is, or hopefully how good it is. Price optimization of a product, from personal experience, is surprisingly difficult.
Edit: so having looked over the datasheets of the IRFS7530 (4.12), IRF7749 (VESC6) and the NTFMS5C628NL (FSESC6.6) I have limited conclusions.
The original 4.12 MOSFET has low Rds_on, but a fairly large gate charge meaning switching losses may be high. But they also have the lowest output capacitance… The VESC6 MOSFET has surprisingly high gate charge and output capacitance, but excellent thermal properties. Switching losses will be very high, but it can handle the heat. Finally, the FSESC MOSFETs have the lowest gate charge of the three and an output capacitance a bit lower than the VESC6 FETs. Switching losses will be lower. I seem to remember someone doing the math on switching losses and came to some conclusion, might be earlier in this thread.
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Man you just edited that as soon as I was reading the last paragraph
Haha gotcha! I was just adding a thought, nothing was deleted.
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There’s confusion about our MOSFETs from many people, according to the datasheet. Yes, it may not as good as directfet or the original 4.12 VESC mos, but according to our real test, the MOS we used now it’s good. Facts speak louder than words, later we will have a test video to prove the MOS performance.
Thanks for your answer.
Sorry, but I do not understand this part (english is not my native language 
):
the MOS we used now
Are you saying that you are not using the mosfets that are in your VESC description ? Are you using other FETs ?
May I repeat my question ? why have you chosen these new FETs and not the original ones (4.12) if the original ones were better ? Is ther an electrical argument ? Is it an availability issue ?
MOS means MOSFET, Sorry not make you clear, new FETs smaller and after we test, it 's same performance in FSESC as original.
Anybody knows FlipSky have a promotions " last week of August"? Come on, not miss "last week"again 
I know that MOS means MOSFET 
. From your sentence, I (wrongly) understood that you used other mosfets than those in the description of your ESCs.
OK, so the reason to use the new FETs is a casing issue. They are smaller than tho original ones.
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well i guess their fets run a bit hotter, but compensate that with a heatsink included. Would be nice to see a performance test vs a usual 4.12 Vesc. At least they reaaaally got the pricepoint down.
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So , where new dual 6.6 FSESC ?)
You mean Dual ESC6.6 90amp continue? Will available next week, sorry for the delay.
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If you haven’t realized this whole esc is on cheaper side, cheap mosfets, half capacity capacitors, I wouldn’t be surprised that expensive high voltage ceramic ones are missing as I haven’t seen any big ceramic caps on the other side…
Just be careful with experimenting with it… Run on comfy safe limits, I doubt this hardware support real alternative limits like original 4.12 or 6…
FSESC4.12 VS MINI FSESC4.20 test video, check on our blogs.
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@BarbaraZ Can you comment on the specific point of ceramic capacitors from @Kug3lis ? If I am correct, this point is not explained in the link. This has shown to be a crucial point of reliability in the VESC design (changelog from VESC4.7 to VESC4.12 and upgrade from Chaka relied largely on higher grader ceramic capacitors).