3foot 2" boat can't keep motors

[gmartin]

I made this boat and killed 2 lipo batts + 3 motors it moves great and turn well to. 1100 kv motor and 12 volt batt pb now but the motor sill gets to hot. The runtime is 20-28min 6-11 times out HELP. this is all home made and the kids and i have fun WHEN it's running.

[CornelP]

From the picture that seems to be a small outerunner, in the 24-28mm range... Waaaay to small for that boat. You should be looking at something in the 36mm, with a 60A or more ESC, batteries good to about 80A.
Just tell us what you have on it and maybe we can be more specific... but definitely too small motor.

[Flying Scotsman]

You could go old school and use a brushed motor with 2 to 1 transmission and 12V. What speeds are you looking for?

Douggie

[Ctonez]

nearly half an hour runtime? wow that's alot.
need more info to troubleshoot, but your running a small motor in a biggish hull for too long with possibly too much prop.

get a temp sensor, take shorter runs, and check temps.
try a smaller prop if yours is bigger than 30mm.
motor temp over 170 will fry the magnets.
too many amps from too much prop causes heat and eventually motor/esc and/or battery damage.
The boat doesn't look 3foot 2" to me...typo?

for more info we'll need:
motor specs/type
ESC brand/rating
prop size
hull size

whereabouts in WA are you?

[ReddyWatts]

20 to 28 minutes is a long run time for an electric boat. How are you cooling the motor and what is your cutoff voltage for the lipos? Which lipos are you using?

The longer you run an electric motor the hotter it will get. You might just need to limit your run time to save your motor and batts?

[photohoward1]

How hot is the water in the Hot Tub. Try cooling that.

[westbeach]

Motor looks way too small for that size boat. Needs a bigger motor.

[gmartin]

3 foot 2" boat

The old batt was a 30c 4000mil 11.1x2 lipo and now 120c 13.2-13.6volt pb x1. The boat is 3foot 2"long 13" wide at center and the prop is a 57mm ose-3bld-316. The gps speed is 28mph. Did i give you all what i needed to to help. The esc 60 amp


Thanks gmartin

[mappo]

Too big a prop to small a controller. pb battery?you will have problems.

[gmartin]

How hot is the water in the Hot Tub. Try cooling that



What you can't test it.

[Flying Scotsman]

This thread does not make sense 1100Kv motor..13V battery equals 14,300 rpm. 57MM 3blade 3.14 pitch that is a BIG prop
20 to 28 minute run time ???? 28mph ???? on the motor in the picture ???

What are the specs on the motor and the ESC you are running.

Douggie

[ReddyWatts]

If you were running the boat at wide open throttle for the entire run, this would be your setup specs.

Battery Mah rating (times) 0.06 (divided by) run time = average motor load in amps

4000 Mah rating (times) 0.06 (divided by) 20.0 minutes = 12.0 amps

4000 Mah rating (times) 0.06 (divided by) 28.0 minutes = 8.57 amps

13 volts * 12.0 amps = 156 watts

need more info:

motor brand/type/model

How many mah was it taking to recharge your batts?

[gmartin]

The pb batt takes 6.5 to 7.2 mah and is 5.3lbs and it can run with 2 but the boat drags a lot and slows down to around 17-20mph . The motor was so hot on a full run the water that hits it steam off. The flymate 60a esc. the help is greatly appreciated on this.

gmartin

If you were running the boat at wide open throttle for the entire run, this would be your setup specs.

Battery Mah rating (times) 0.06 (divided by) run time = average motor load in amps

4000 Mah rating (times) 0.06 (divided by) 20.0 minutes = 12.0 amps

4000 Mah rating (times) 0.06 (divided by) 28.0 minutes = 8.57 amps

13 volts * 12.0 amps = 156 watts

need more info:

motor brand/type/model

How many mah was it taking to recharge your batts?

[gmartin]

Will this work for water cooled with what i have 3600 KV RC Water-Cooled Brushless Motor IM294

[ReddyWatts]

Since it is getting an 1100 kv motor to hot with your setup, it will definatley not work with a 3600 kv motor.

If they are 4000 mah batts the 6.5 mah charge input cannot be the correct reading.