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[loinerlad]

Right guys I am in need of a bit of advice here please

I have recently bought an old boat which is approx 47" in length, it is fitted with a single Torpedo 850 motor and a 50A esc, the boat came with a 12v 7amp Lead acid battery which I used on the lake this weekend. the boat flew on the water and looked amazing! but when I brought it back and lifted the superstructure off the motor was red hot and yes there was smoke!!  the esc however was absolutely fine. I tried a 6v battery and the motor was cold but the boat had no speed to it.
Is the 12v battery far too big for this kind of motor?? if so what kind of battery would you recommend as I realise the Lead acid ones are a bit out dated now.

Chris

[boatmadman]

Hi,

Rather than going down the new battery route straight away, why not try a slightly smaller prop first. This will reduce the load on the motor, and, if you step down a little at a time, your speed reduction will be minimal.

Experiment with cheapo plastic props before you buy decent ones.

Ian

[nemesis]

Hi, You may have cooked the motor by now, do what has been suggested & prop down & it may pay you wrap a cooling tube round the motor once you are sorted with the first problem. nemesis

[loinerlad]

Thanks for your replies, I will definitely try a smaller prop as the one that is on is quite large, probably about 40mm! my local model shop sells the plastic ones for about a quid so I will get a few different sizes and as you say step down gradually 

[Andyn]

fitted with a single Torpedo 850 motor

I think I found the source of your problem

[Tug-Kenny RIP]

Which is   ????????????????????

[Andyn]

fitted with a single Torpedo 850 motor

 

[Tug-Kenny RIP]

You don't like the 850, I take it.

[Andyn]

It was a good motor 20 years ago...

Personally I would change the motors and fit some 900 motors water cool them and run on 24v for each motor using Nimh packs  and 55mm 2 bladed props this set up should give you a decent running time and going like a train

Dave

Says it all really

[Shipmate60]

So if it was good 20 yrs ago what has changed in the motor?

Bob

[Andyn]

Comparatively to what was around then it was good, but now it belongs in one place....

[dmn1]

Hi, If the motor is still working o/k and you are pleased with the performance fit a cheap computer fan, fit it close to the motor & run it off the 12 volt main battery, cheap & cheerfull.
Regards, Dave.
PS we can all spend loads a money on things that dont need it!

[Stavros]

If you MUST insist on using a very power hungry motor then may I suggest you do the following


Change the lead acid batt for a 12v stick pack...WHY..........less weight for the motor to move
Change the Prop up to a 55mm............WHY....................More efficient and is the optimum size for that motor
FIT a cooling coil...make one up using copper brake pipe fit a cooling pick up pipe IN LINE with the tip of the prop and obviously an outlet....WHY.......to cool the motor

Changing to the prop size downwards is a total waste of time been there had the tee shirt etc


Ultimately change the MFA850 for a 900 series motor 55mm prop 24v water cool it ............sit back and enjoy your model as it will fly

Dave

[loinerlad]

Thanks for your advice stavros  I have just had a quick look at 12v battery packs available on the net, I was thinking all along about replacing the lead acid battery with a pack to reduce weight of the boat but was unsure which to get, would you recommend any in particular? also I know nothing about these packs so will I get a decent run time out of the larger ones before having to re charge?

Chris

[DickyD]

Thanks for your advice stavros  I have just had a quick look at 12v battery packs available on the net, I was thinking all along about replacing the lead acid battery with a pack to reduce weight of the boat but was unsure which to get, would you recommend any in particular? also I know nothing about these packs so will I get a decent run time out of the larger ones before having to re charge?

Chris

More amps, longer run time.

Component shop for all batteries.

Good service, price and cheap P&P.

http://www.component-shop.co.uk/html/large_packs.html

[loinerlad]

Cheers pal, just seen the 12v 3700mah on the link you sent me, think this will do the trick??

[Stavros]

Thanks Richard you beat me to it ......Personally I would go a higher amperage if you can HIGHER the better.

With regards your run time SORRY to say this but with a 850 NO batt is going to give you a long run time as that motor is AMPS hungry,I have seen a current draw in excess of 20 amps with one and 30 plus on another both 850's thats why I suggested a 900 series motor.I used to regularly get 40 Min's on a 48inch Perkassa running 12v and a 55mm prop as I suggested.....Your choice


Dave