In need of run times for big/huge electric hulls

**Peter A** · 08-08-2019, 03:29 PM

HI Mike
A valid and important question is what sort of speeds you are after as the faster you go, the shorter the runtime. If you are looking for 60 mph plus you are only going to get 2-3 mins. If you are looking at fast scale speeds the runtime will increase but much more than 5 mins would likely be unrealistic on 10000 mah. Any info offered up will only be a ball park as the drives you are running will have much bigger energy losses over flex shafts. You may find that going to 8s will be better depending on the speed you want and the props required.
Can we assume you are planning to run 10s 10000mah on each motor?
Are the drives 1/4" or 3/16" shaft? This will determine what prop sizes you will have to work with, i.e. 1/4" shaft means you will need larger size props 65mm and up.
There are a few guys with big hulls that may be able to get close to what you are wanting to know.
My own biggest is a 45" hull (ex gasser) running a TP 56110 650 kv. On 10s 5000mah and an X455/3 speeds are around 55 + mph and use around 3000mah for a heat race (I only race it). I have a 42" Osprey with a TP4070 440kv that runs for 20 mins on a prather 245 and 12S 20000mah, which I use for offshore endurance racing.
I know my boats are a fair bit smaller, but you do have the room to put more batteries in that hull for longer runtimes if you wanted.

**5150WS6** · 08-08-2019, 03:57 PM

Peter,
That's pretty much perfect as far as what I'm looking for. I know with boats there are soooooo many variables. But I'm just looking for ballpark numbers for sure.

And I should have clarified, I will be running a 10s 10000mAh per side. One for each motor. And yes, the hull is huge with lots of room so I can add more if needed.

The shafts for the props are 1/4".

I'd honestly be happy with 50mph. And if I could get around 15 minutes run time? I'd be over the moon happy. I'm hoping that's not too out there but we'll see. This is my first big brushless boat so.

I had a twin Zenoah set up to go in it with a gear box and the works. But I use a chair to get around so trying to pick up and maneuver that big heavy hull with that set up and not fall out of the wheelchair was a joke. The brushless setup just suits me for ease so much better. And it'll be nice not to end up covered in gas and oil crap! LOL!

Thanks again Peter for the response. Looking forward to more.

**Fluid** · 08-08-2019, 06:46 PM

One reason you don’t get a lot of responses is not because folks want to criticize you, it’s because very few boaters here have experience with what you want to do. Most here either race, or want very high speeds - not your goal. Too, because the boat exceeds the insurable length for most (60”) few run boats that size. There are a few who do, but specific experiences will, as you’ve discovered, be few. Lots of opinion though......

But to specifics, 15 minutes of run time on 10S means an average amp draw of 30 amps per motor. That won’t get you anywhere near 50 mph.

.

**MarkF** · 08-08-2019, 08:32 PM

I have built several big monos and a cat. But mine were for racing. I used a 680kv motor on 10s 10,000 and a big gas prop. I got 65 mph and 3 minutes with that set up but could have got more if I wanted to prop down. Your doing twins which helps a good amount with pushing a bigger boat. I don't know what prop your set up likes but I hope there big ones. Your going to have to build the boat and run the packs you have and see what you get. You will have to play with props too. I sell batteries and can make you some 5s 16,000 or 22,000 mah batteries for you to get some more run time if that helps.

**meangenesracing** · 08-09-2019, 12:10 AM

Originally posted by MarkF

I have built several big monos and a cat. But mine were for racing. I used a 680kv motor on 10s 10,000 and a big gas prop. I got 65 mph and 3 minutes with that set up but could have got more if I wanted to prop down. Your doing twins which helps a good amount with pushing a bigger boat. I don't know what prop your set up likes but I hope there big ones. Your going to have to build the boat and run the packs you have and see what you get. You will have to play with props too. I sell batteries and can make you some 5s 16,000 or 22,000 mah batteries for you to get some more run time if that helps.

Mark, so you make 5s 16,000 MAH Batteries? Would they be heavier than 2. 5s 5000 MAH revo lipos?

**MarkF** · 08-09-2019, 12:44 AM

Yes they would but you got a big boat.

**5150WS6** · 08-15-2019, 03:35 PM

Mark,
I’m interested in what you can do for 5s 22000mAh batteries. Mainly on price. I’d need 4 of those for 10s on each motor....and probably more like 8 so I can have more than one run. Also might have another buddy interested depending on cost. I know batteries aren’t cheap

**MarkF** · 08-15-2019, 06:07 PM

I can do $350. 00 each if you buy as many as you say. Normal retail is $425.
Specs are 52x92x200mm 2250g

**rscheffer** · 08-23-2019, 05:57 PM

Hi there i own a sv43 outerlimit scale model made in germany by Andy
Its a 1.80m 18 kg but light running stept big boy hull.
Motors are 2x TP 5850. 600 rpmv
Controllers 2x swordfish 300 a
Drives strut ( mtc from germany)
Running time 10s 5000 mah zippy flightmax per motor 4,5 min
When using my normal setup off 2x 10s 5000 mah zippy flight max ( budget lipo setup) per motor this ship weight is 18 kg and runs 95 kmh for 9+ min. running 6514/3 propshops. Alternative props i use are the octura x470 same speed ,better accelleration from start but little less running time.
Top speed with the same 1000mah per motor setup using only andy brown 7016/3 propshop props was close to 115 kmh but only for an few short speed runs because of the much higer amps
When running a non stept hull and also z drives the amps will be higer because of the energie loss in the drive and water friktion.
I hope this info can help you.

https://youtu.be/dS7zVzr9SHE

The hull corner handeling is what it is for a stept scale hull but also was not yet optimal trimmed in this video.
Here is another one exactly the same setup run by a guy in France , nice slomo video

https://youtu.be/3zpqacQQu9E
Greatings Ramon ( from the Netherlands)

**5150WS6** · 08-25-2019, 09:58 PM

Ramon!
Thank you for the post! And thanks for the video links.

Just to clarify, you are only running 5000Ah total or doubled at 10000mAh?

Very happy to see that some decent speeds and run times are achievable!

**rscheffer** · 08-28-2019, 12:36 PM

Normal 10000 mah per motor .9+ min running time
4x10s in total 6kg lipo’s

is my normal setup , i like the long runnig time

and its not as hard on the lipo’s
But the 5000 mah per motor is also very good 4.5 min running time

**madmikepags** · 08-31-2019, 02:40 PM

One thing that I want to know is, on the outdrives, are the props surface drive or are they submerged? With a surface drive you can run a a much bigger prop than a submerged drive, the submerged drive will draw a LOT more amps. A surface drive will be much more efficient and will offer better speeds and better runtimes.

**5150WS6** · 09-04-2019, 02:57 PM

Madmike—
That’s a good point. I know the MHZ drives run props semi-submerged. Not as much as a surface drive I’m sure but not completely submerged. So that will draw more amps out of the hole probably until get gets up on plane. Something I’m willing to deal with for the killer scale looks of the drives! :)

**RogerZ** · 09-08-2019, 01:50 AM

https://www.youtube.com/watch?v=oKaW_zZVLPw&t=40s

Roger

In need of run times for big/huge electric hulls

In need of run times for big/huge electric hulls

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