Medusa V2s and MMM/MM - Need some advise!

Thanks Finnster, totally forgot about that formula :D Makes sense now.
I could do 8S a123s easily, as that just needs me to series up the 2 4packs, but I'm pretty sure that's more volts than the MMM can handle :(

Oh, I also forgot the most important reason that I switched to 2p config - runtime.

We run 6min races at my local club, and they're starting to add in 10min mains now, so the 1p config meant I couldn't finish races.
The reason I dropped from 5s2p to 4s2p was weight.

Also, someone just pointed out in another thread, could my uber long motor wires (almost 20cm) have something to do with the higher amp draw with a 1p pack?

And another question; for arguments sake, what would happen in my setup if I changed out the 8XL with say a 6XL (ignore that the Feigaos are only rated to 30k RPM). The 6XL would be higher KV and so in the same setup what would happen? I assume the car would go faster and I assume pull more amps, but what else? Just trying to get my head around what the pros/cons are :D

[BL_RV0]

Originally Posted by cdis

Thanks Finnster, totally forgot about that formula :D Makes sense now.
I could do 8S a123s easily, as that just needs me to series up the 2 4packs, but I'm pretty sure that's more volts than the MMM can handle :(

Oh, I also forgot the most important reason that I switched to 2p config - runtime.

We run 6min races at my local club, and they're starting to add in 10min mains now, so the 1p config meant I couldn't finish races.
The reason I dropped from 5s2p to 4s2p was weight.

Also, someone just pointed out in another thread, could my uber long motor wires (almost 20cm) have something to do with the higher amp draw with a 1p pack?

And another question; for arguments sake, what would happen in my setup if I changed out the 8XL with say a 6XL (ignore that the Feigaos are only rated to 30k RPM). The 6XL would be higher KV and so in the same setup what would happen? I assume the car would go faster and I assume pull more amps, but what else? Just trying to get my head around what the pros/cons are :D

Yes, motor wires do cause more resistance, so that would increase amp draw. The 6xl would run much hotter than the 8xl- check out the thread entitled "Alternative Motor" in the brushless section. One of those models perhaps the ~2370kv model would run well on 4s2p. (That's the kv of a 7xl, approximately. If you have to stick with feigao, get a 7xl, and try 5s2p, if the weight is unbearable, consider moving components to the motor side, or adding small weights to help counterbalance some of the battery's weight. I think you should try one of those 3674 motors, for only $46 it's worth a shot.

[Finnster]

Originally Posted by cdis

Thanks Finnster, totally forgot about that formula :D Makes sense now.
I could do 8S a123s easily, as that just needs me to series up the 2 4packs, but I'm pretty sure that's more volts than the MMM can handle :(

Oh, I also forgot the most important reason that I switched to 2p config - runtime.

We run 6min races at my local club, and they're starting to add in 10min mains now, so the 1p config meant I couldn't finish races.
The reason I dropped from 5s2p to 4s2p was weight.

Also, someone just pointed out in another thread, could my uber long motor wires (almost 20cm) have something to do with the higher amp draw with a 1p pack?

And another question; for arguments sake, what would happen in my setup if I changed out the 8XL with say a 6XL (ignore that the Feigaos are only rated to 30k RPM). The 6XL would be higher KV and so in the same setup what would happen? I assume the car would go faster and I assume pull more amps, but what else? Just trying to get my head around what the pros/cons are :D

Yes, pull more amps and heat up pretty bad. Its better to make power w/ volts rather than amps. In your 8XL setup you are pulling ~120A. You have to have a 2p config. 6XL would pull maybe 140-150 i would guess. It may stress the 2p a bit even if you drive it hard. It may be fine depending how you drive, or you may thermal in mins. Really depends.
I have doubts you can make 10 mins on 7 cells tho. In my Revo I was pulling 1600mah out of a 10 cell pack during a 10 min race. I wasn't driving really hard either. If you scaled the motor to the voltage, I can see 8 cells being enough total energy, but 7 would be close. There are certain holes in configs a123s just don't cover well. You may just have to bite the bullet and get lipos rather than buying tons of motors to try to get the a123s to work.