Novak HV MAXX

[Hotti]

Hi.

I have novaks hv 6.5 set in my emaxx.Manuals says that esc can take 6-14cells/2-4s lipos,and motor 6-14cells.I wondered that can it take two 3s lipo packs in series(22.2V)?Or is the maximum two 2s packs in series? :roll2:

[kufman]

2 2s lipos is series is a 4s lipo. No, it cannot take 22.2V (6s lipo).

[Hotti]

ok...i was thinking of that but want to make it sure.

[ElectricThunder]

You can do a 2s on the one lead that feeds the BEC, and a 3s on the other lead for a total of 5s, but that's definitely out of warranty. Team Novak themselves did such a setup (running the HV4.5, albeit in a touring car) at the world's fastest rc car challenge.

IMO, 4s is plenty for that motor (especially considering it's a 4.5 turn and already spins some high RPMs).

[GSMnow]

Why not just run the two 3S packs in parallel for 3S2P and get huge run time along with the 3S power? You will actually have a bit more p[unch with the greater current available, so you can trade off some of the huge run time with a bigger pinion gear. 4S will be a bit faster on top speed, but this won't be a bad setup at all.

[SpEEdyBL]

You can do a 2s on the one lead that feeds the BEC, and a 3s on the other lead for a total of 5s, but that's definitely out of warranty. Team Novak themselves did such a setup (running the HV4.5, albeit in a touring car) at the world's fastest rc car challenge.

IMO, 4s is plenty for that motor (especially considering it's a 4.5 turn and already spins some high RPMs).

Hes running a 6.5 turn. 5s won't hurt it but its not covered under warranty.

[ElectricThunder]

Hes running a 6.5 turn. 5s won't hurt it but its not covered under warranty.

Oops...:D I thought I saw 4.5 turn somewhere. Eh...

[Hotti]

Yes..ill run 6.5...

so i just ordered two 2s2p 8000mah lipos.What will the run time be in series connection?I will also get someday 4.5 motor and 3s 8000mah lipos.Run time,parallel, with 3s 8000mah?

[SpEEdyBL]

There is no point in running the HV4.5 on 3s. The HV6.5 will be about the same speed but will pull less current and be easier on the controller.

[GSMnow]

It would be nice if Novak continued rating their motors with KV and maximum rpm (voltage). The HV (long can) motors will have a much lower KV than the same turn Velocity (short can) motor. With ALL brushless motors, the higher turn, lower KV, running at a higher voltage to make the same rpm will make more power. Low turn (high KV) motors are just a way to get more power out of a low supply voltage but they require more current to do it. More current means greater losses in the batteries, wire, ESC, and even the motor windings. Using a higher voltage is always better unless you are limited by rules, max rpm (practical gearing), or ESC limits.
The Novak Velocity series was built around a 6 cell rules limit so they use very low turn (high KV's) and handle high currents. Not the most efficient way to make power, but they do make great power within a 6 cell rule. The HV series on 4S LiPo with a 10.5 turn would make alot more power than even the 3.5R. And it will do it at a lower rpm with a ton more torque. The HV6.5 on 4S will even turn about the same rpm as the 3.5R on 6 cells but with far more torque.

[ElectricThunder]

They have Kv ratings though. The HV6.5 is 3100 kv, and the HV4.5 is 4800 kv. They suggest max voltage at 4s for the system, but since the HV4.5 is spinning at almost 70k RPM under load, I would assume the motors are good to around 65+k RPM under load. The rotors are nickel plated, so I doubt they'll fly apart from centripetal force unless you're spinning at a crazy high RPM above 100k for very extended periods of time.:D

[CharlieS]

http://www.teamnovak.com/products/brushless/motor_spec_chart.htm

[GSMnow]

Thanks for the chart, the numbers are pretty close to what I suspected. The sintered rotor should lower the KV and bit and it seems to have (SS8.5 Pro has only a 5000 KV). But why does the bonded SS5800 and EX8.5 also have a 5000 KV then? Shouldn't it be more like 5800? I know my brothers SS5800 seems a little slower on top end with the sintered upgrade, but it has a TON more torque and runs much cooler so he can pull alot more gear and still have a longer run time. The odd thing is, the ESC even seems to run a tick cooler. I didn't expect that. His friend is running a similar touring car with a stock bonded SS5800 and when they geared for the same top speed, the sintered pulls much harder in the mid range, about the same from a stop (wheel spin limited, I guess) and at the top end, the bonded looses torque slower, the sintered pulls hard right up until it is just about topped out and then stops accellerating, sorta like my Mamba Max 5700. Which is also a sintered rotor setup.

Brushless is the only way to go. Sensored / sensorless, who cares? Lose the brushes. Last night I won my 7 minute main because the faster brushed 4wd guy had his batteries dump at the 5min 30sec mark (he had about 1 lap on me) and I drove around a lap for the lead and put on 2 more full laps before the end. AND I had enough battery left to run another 5 minutes. I could gear faster, of course, but on our tight track with just 2wd, I could not use it like the 4wd could.

[CharlieS]

The original 5800 and 4300 numbers were not as accurate as our current numbers. This is also why we stopped calling the numbers by their KV number. How you measure, calculate or check them can done slightly differently. KV is just one part of a bigger formula.

The numbers we have now were measured by us with a constant load and a very very large power supply.

Sintered rotors are stronger magnets, so they may have less RPM under no load, or lower loads, but you're right, they pull more gear and end up the same speed. They will run cooler and have more runtime then a bonded rotor because they make the motor more efficient and have more torque at the same time.