Battery VS Boat speed

[jbyers]

I have a HK Genesis running a Leopard 4082 2200Kv with a X645 prop and 5S. Im getting a max speed of right around 37mph according to the GPS and 43mph on 6s. Compared to what I read this is really slow

Im running mainly two 5s 2200mAh 30c batteries in P.

Could the issue be that Im just not getting the amps needed to push the higher speeds or do I need a more lifting prop. I was expecting closer to mid 50s on 6S and having to retrieve the boat in the middle of the lake upside down on 6S.

Any thoughts would be appreciated.

[Mattwarner]

somethings definitely wrong here, are you sure the motor is the correct kv? i had the same hull and motor (1600kv) and with an M445 and 6s was hitting high 50's no problem, youve got way more pitch and more rpm (too much as thats a 4s motor)

I would definitely recommend higher capacity 4s packs at least 4000mah in parallel and check your motor kv, also maybe post some pics of your strut height/angle as this maybe causing you running issues.

[jbyers]

Batteries VS Speed

The top of the strut was 1/8th of an inch below the top of the mounting bracket. I tried moving it up flush thinking that maybe it was the angle of attack for the prop but that made no difference. The motor has 2200Kv stamped on the side. At 5S the 180amp speed controller and motor both dont even get warm. The batteries are warm but not overly hot. Granted its frigide outside the last couple of runs. May be different in August. Ill take photos when I get home and see what you think.

[lenny]

Have any video's of how the boat is running ?
Sounds like it is running wet,
What are the temps on everything after a 1 minute run ?

[martin]

Your running a combination of very high rpm with a lot of prop & possibly to deep a strut, on 5s your running 40700rpm unloaded & 6s nearly 49000 rpm unloaded. A x645 is a lot of prop at those rpm, re strut depth with the hull sat on the ride pads the bottom of the strut needs to be 4-5mm above the ride pads. To check this sit the hull on a table & the bottom of the strut should be 5mm of off the table.

[jbyers]

Your running a combination of very high rpm with a lot of prop & possibly to deep a strut, on 5s your running 40700rpm unloaded & 6s nearly 49000 rpm unloaded. A x645 is a lot of prop at those rpm, re strut depth with the hull sat on the ride pads the bottom of the strut needs to be 4-5mm above the ride pads. To check this sit the hull on a table & the bottom of the strut should be 5mm of off the table.

Thats an easy check. I can follow up on it tonight. Most people make videos to brag about how fast thier boat is and I was more dissapointed then in a videoing mood. I can make one this weekend and let everybody take a look.

[jbyers]

Really dont want to run 6S. Only went that high due to lack of performance before. I have smaller props and feel that a X642 might be a better option. If its running correctly then a 645 may be faster then I want the boat to go. I want it fast but not upside down.

[larryrose11]

Aside from any hardware settup issues, that battery configuration is a problem
2.2 Ah *2p*30C = 132Amps by the generous battery specs.
The batteries voltage ill collapses, and Im guessing you have the LVC disabled on your controller.
Greater capacity batteries (4000 - 5000) and MUCH higher C rating (60+) will go a long way.

[jbyers]

Actually, I usually raise the LVC but my programmer has not made it in for the speed controller yet. So for now its at the default, 3.2 I believe.

I would imagine Im pulling well over 132 amps on the surges. For an experiment Ill wire up a third battery in parallel and see what happens. May not be a perfect test since Im adding weight but should give an idea before I drop 200$ on batteries.

[lenny]

The video's help to see how a boat is riding on the water for tuning.
That hull likes added weight and can run better with it,
If it is setup right at the start.
I run that stock hull with a sk180amp esc / neu 1515 1Y 2200KV motor / x442 prop on two 4s 40c 5800mah packs,
And it handle better and gained some speed at 58 mph gps.

[martin]

assuming its either a T180 or Seaking 180 they suffer from premature lvc, turn the lvc off & run it briefly to see if your speed increases. As said not the ideal battery set up either.

[Fluid]

Without a video it is tough to know the cause of the low speed for certain. I too suspect that you have inadequate battery power to supply the load of that "large" prop, you are probably pulling well over 150 amps out of packs which are lucky to deliver 100 amps without a major voltage drop.

First try a smaller prop - particularly on 6S. Let the motor breath and increase the voltage available from those tiny packs. The strut may be too high, hard to say. Where is the CG, too far forward and the boat will plow. What is the timing advance? Have you sanded the bottoms of the steps smooth and dead flat? These are all things which can cause a "slow boat".



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[iop65]

5 s is ok for that powerplant in a cat with GOOD hardware ,cheap junk won't last long ,but wouldn't go 6s or it must be top quality hardware ( example:h&m stuff!)

like been said :you need better lipo's , at least 5.5mm connectors a 180A esc ,....

[TristanJones]

I'm saying with that much load your dropping cell voltage under load below LVC and its cutting you back. get some better packs, turn off your LVC and time your runs
I have a m445 T180 2200kv hobbyking motor set up, mine has been 68mph....
Disable your LVC, run one 2s nannotech 5000 65-130c pack and one 3s pack of the same specs, put the 3s pack on the left hand side.
That x642 prop will haul ass on that thing, should get you into the 70mph zone easy.
An offset rudder is important as hell also use a very well sharpened, thinned and balanced prop.
The COG is VERY important in this hull start with it around the middle of the middle ride pad or step move it back till it is too loose then move it forward a touch.
here is a video of mine on 5s, with a rubbish 41.5mm 1.4p CNC prop (it was windy so I propped it down). If yours isn't running like this, there is something wrong.
P.S. Your going to need to reinforce the hull to keep the motor mount in it.... Ive put a lot of work into my hull to handle this.....

[f1rogers]

X645 @ 30,000 rpm =68mph X642 @30,000rpm = 63mph