MC running on one 4s or two 4s in parallel

[jetskier]

Hi guys, just got a MC from eBay but not here yet. All my batteries are 4s for use on my Revolt. My question is can I put or will it fit one 4s battery in front of the motor on a MC or can I put 2 4s batteries and re wire the ESC to parallel or will that be too heavy. Thanks

[BHChieftain]

Not sure the 4S will fit in front, but even if it could, that would mess up the COG. The boat really needs 2 packs on the sides towards the back. I'd give the 4S2P config a try before buying any new packs-- I bet that would work well and the extra runtime would be nice.
Chief

[petej]

Hi,

I run my MC with (2) Venom 4S 3200mAh 30C packs in parallel, on the sides as far aft as possible. Battery dimensions, L: 133mm, W: 42mm, H: 30mm, weight: 369g.

My MC configuration:
Leopard 4074, 2200kv
Seaking 180A ESC
Octura x642 prop, sharpened, balanced, raised slightly for bow-lift.

Running WOT: Mid-40s, 7-10 minutes.

The MC can handle light chop quite well, but is prone to sub-marine-ing, but will pop-up and run right away.

[jetskier]

thanks guys for the inputs. can't wait!!

[jetskier]

just tried 2 Grimracer 42000 4S batteries in the boat for balance only one plugged. Seems slower them my Revolt, cavitates during start up, and motor and ESC seems to run hotter them my Revolt. The struts is 3/16 off the table when resting on sponsons. how much should the cooling tube stick out from the bottom. Maybe the batteries are too heavy? This is my 1st cat, any inputs would be appreciated.
Thanks,

[petej]

What prop are you running?

When my MC was stock, using 14v (2S in series or 4S parallel), with a 42mm dia. prop, my records show hi-30s. The stock ESC is rated at 60A. After upgrading to a Seaking/Turnigy 120A ESC, both acceleration and top-end speed were much better.

[jetskier]

prop is Grimracer 42X55 same as my Revolt stock prop. I was reading some pass post that Grimracer suggest having the strut touching the table when resting on the sponsons, wondering is my strut too hi at 3/16"?

[petej]

MC strut is about 1/4" above the table top and the water pick-up tube is 1/4" below the transom bottom.

[Mjpcarbon]

running 4S

So am I to understand the stock setup will tolerate 4S ? with a prop change

[petej]

Yes, the stock motor, ESC and battery connection is configured for (2) 2S (7.4) volt batteries in series (14v total) and will support a Grim Racer 42x55 prop. I also used Octura x642 prop, 1.6 pitch, 42mm diameter, with good results.

[jetskier]

took you advice. so far, this is the my best setup with choppy conditions. two 4S 30C 4200mAh in parallel, strut touching table w/ +1 to 2 deg, and 5/32" brass cooling tube. motor and ESC runs much cooler now, and the extra weight helps keep it from blowing over.

Not sure the 4S will fit in front, but even if it could, that would mess up the COG. The boat really needs 2 packs on the sides towards the back. I'd give the 4S2P config a try before buying any new packs-- I bet that would work well and the extra runtime would be nice.
Chief

[jetskier]

http://youtu.be/MwWdxiK4sF0

here's a short clip of my stock MC running two 4S 4200mAh in parallel. pond is a little small, but still fun during lunch break.

[Mjpcarbon]

Well that looks pretty sweet, what is your run time and may ?

[jetskier]

I try to keep it under 10min. funny, boat looks faster in the video

[petej]

Very nice.