Motor amp draw

[jjl5590]

Hi all,

I'm curious about the amp draw for different motors, and was told that the values posted by manufacturers can not always be trusted.

In my Kraton I was previously running a SSS 4092 2140kv motor. It was great, temps were always low, speed was good and I got about 20 mins out of my 6s lipo. After the run, the cells would be around 3.2-3.4v.

I then got a Rocket 4092 1650kv motor and it was a similar story.

However, I wanted a bit more speed so picked up a TP 4070 2080kv motor. This time I only got 15 mins runtime, and when I went to charge the lipo I saw two of the cells were below 3v. I've always had my Max6 lvc set to Intermediate.

Does this mean the TP is drawing more amps? My other option was to get a Hobbywing 4985 1650kv, but I don't want to if it's got a similar amp draw... I'll just go back to the Rocket

 

[Malice]

Your rocket 4092 1650 is rated to draw 160. That TP4070 2080 is rated at 300. If going by manufacturer specs that is a 140 potential increase in amp draw. Testing of motors is done in a lab type setting. I think you will find variances in rated vs actual in kv and amps amongst them all.

 

[jjl5590]

Your rocket 4092 1650 is rated to draw 160. That TP4070 2080 is rated at 300. If going by manufacturer specs that is a 140 potential increase in amp draw. Testing of motors is done in a lab type setting. I think you will find variances in rated vs actual in kv and amps amongst them all.

True - i guess for the minimal gains the TP brings, it's not worth the greater cell stress and shorter battery life, imo. Unless I go to 8s...

 

[jondilly1974]

True - i guess for the minimal gains the TP brings, it's not worth the greater cell stress and shorter battery life, imo. Unless I go to 8s...

If you go 8S on a 2080kv motor, you’re gonna have heat issues. TP motors arrived really made for street racing. Drag and speed runs. They aren’t ideal in a basher IMO. The Rocket and SSS motors you had were better off.

 

[jjl5590]

If you go 8S on a 2080kv motor, you’re gonna have heat issues. TP motors arrived really made for street racing. Drag and speed runs. They aren’t ideal in a basher IMO. The Rocket and SSS motors you had were better off.

Yup I'm starting to realise this :') I thought originally they were just good-quality boat motors

 

[LibertyMKiii]

It is also worth noting you are comparing 40x92 motors to a 40x107
TP's motor ratings for voltage are based on rpm and not if the motor would run cool or not.

 

[jjl5590]

It is also worth noting you are comparing 40x92 motors to a 40x107
TP's motor ratings for voltage are based on rpm and not if the motor would run cool or not.

Yeah, well the TP's much longer and has much stronger magnets so I suppose it's only logical that it'll draw more amps and be harder on the batteries

 

[olds97_lss]

I'm lucky if I get 17 minutes out of the max6/blx2050kv in my outcast or my ERBEv2 with 5000mah packs. I just ran my ERBEv2 the other day at the grass bmx and hit LVC at 15:05 with 2 x HRB 5000mah 3S 50C. I was running it pretty hard though. Trying out the stock ERBEv2 talon ext tires. They spin/slip a lot more than the trencher 3.8's I had on it and it was slower due to the smaller OD. I bumped the pinion up 1 tooth when I got home for next time.