Mono First Run

[Eggo83]

hey all

i posted pics of my first mono build about a month ago, since then i have run it for the first time today...

it went ok. well sort of

-the battery puffed (3s 2200mah 11.1v 12c lipo)
-and the boat cut out for some reason after a small amount of run time

so i guess does anyone have any ideas why on both issues?

i am running a 120amp esc and a HXT 36-56 2700kv brushless with a Graunper K series 40 carbon prop, any input would be greatly appreciated.

cheers

[Mich. Maniac]

what brand pack? what hull was this in again? were any of the items hot? too hot that you couldnt touch and hold your hand on them?

[RMZDADDY]

If you're running 3s1p, I'm thinking a 2700kv motor and a 40mm prop is too much for a 2200mah pack with only a 12c rating. That comes out to 26.4 amp cont. rating.

[SJFE]

Tim's numbers are right on. Depending on the hull I'd bet you where twice the amp rating of thos packs.

[Eggo83]

thanks heaps for the help, but i have no idea how to work the amp draw and stuff? im still learning and you guys on here are the best to learn from!! its a 30'' hull also. any help is good help....

[Eggo83]

and also how do you choose a battery that can handle more amp draw?

[RMZDADDY]

I would buy a 25-30C pack with at least 3300mah capacity. A 25C 3300 pack would have a 82.5amp cont. rating. A 30C 3300 pack would be rated for 99 amps cont.
As far as explaining the math I think Reddywatts says it all in post #10 in this thread titled "Ideas on building a reliable BL system by Reddywatts" Many questions can be answered by reading this thread.
http://forums.offshoreelectrics.com/...read.php?t=271

[NorthernBoater]

Check this sight http://www.rclipos.com/RCL.html. You want to be running about 30-40 amps of what your packs are rated for. For just sport running I would recommend paralleling the packs and the packs will last longer.

[Eggo83]

thanks all for the help and links i greatly appreciated it!!!!! i will let everyone know how i go! cheers again

ps: building a new boat 32'' mono! will show picts as i go

[Jeepers]

On that large of boat 4s would be a better voltage range swap the motor for a 9XL and a 42mm prop it will run good.

[peells]

Well 12s That is a bunch of voltage I hope your speed control did not fry,
Well if you still have the battery packs plug in your balancer and when you find the one which acts abnormally try and remove the protective covering (if you are savvy to being careful) expose the soldered connections and take a look there!! you may just find melted solder which connects the cells into series, what I have been doing is jumpering the center connection with a 12aug piece of wire and changing the output leads to 10aug after you do that, I wrap some tape around the top forming a dam in the shape of the battery and fill it up with high temp silicone and let dry for a couple of days then if you do not over heat the batteries you should be good to go. Now I do not know how many you can use in series but I do know I use 2 -3s in series and so far so good. BUT bear in mind you need to be careful not to arc the connections or short out the pack IF YOU ARE UNSURE OF YOUR ABILITIES DO NOT DO THIS, AND IF ANY OF YOU KIDS TRY THIS HAVE ADULT SUPERVISION, I really do not want to see anyone hurt so please be careful this does work I have salvaged two packs so far and with the cost and all you guys know where I am coming from, Good luck and be safe.
also check out my blog, http://boatsbypetere.blogspot.com/

[ace028]

he means 12c not 12 cells. 12c is 26.4 continus amps for that particular pack. I agree with using a high mah and c rating battery, a hull at 30" is too much for a 3s pack at only 2200 and 12c discharge rate.

[Eggo83]

awesome help guys! pity i never asked first and i wouldnt have fried my lipo

[peells]

I t seems like everyone here just wants to see you have a good time because they know you spend a lot on these projects!!

So did the connection inside your lipo melt away? and you really do need to bump up to a 25-30c continuous discharge rate. And get as much Mah as you can afford.