6-cell or 7-cell

[Kirker]

I recently got a new r/c boat (SuperVee 27 by AquaCraft) which I haven't run yet. The motor and esc are water cooled, have Dean Ultra connectors, and are rated at 18V, 45 amps. The basic setup is that it is powered by dual 6-cell battery packs. Just for some extra "gusto" I was thinking of running dual 7-cell packs in it instead. From the little that I know, and from asking others, I feel fairly confident that the hardware could handle it ((2) 7-cell packs = 16.8 volts). Is there anything in the "amp" equation that I am missing? Or, is there something else that I might be missing altogether?

The same idea from a couple other angles: Do you think that dual 7-cell packs, instead of 6-cell, is really going to give me enough added performance that it makes it worth "experimenting"? Or, given that this boat is supposedly twice as fast as my last boat, should I just take "baby steps" and try 6-cell packs first and then move up later if I want? That attitude makes perfect sense but there is the cost issue (more battery packs).

Any thoughts?

[TunaCan Charlie]

Just a thought...

Since this boat is new to you, take her out a few times with just the 6 or 7 cell packs in. Get a feel for the way it reacts to turns and accelleration before you torch it... :D

[Kirker]

LOL Tunacan!!! Yes, "baby steps"!!

[TunaCan Charlie]

^^^ great movie!!!

[Rex R]

the word that I've heard is 14 cells is pushing the esc limits. but considering that it will do 31 mph out of the box... keep in mind that your 'pond' is gonna seem kinda small(this happens with any boat that goes over 30 :)). run it on 12 till you get used to it & you get things adjusted to your liking.

[BoatDoc]

yup, keep it at 12 cells. you'll be happy with it.

[Fluid]

If you want higher speeds, rather than using 14 cells considering buying higher performance 12-cell packs. These will have higher voltages and lower internal resistance, delivering more power without over-volting the ESC. You will have to watch the heat though, the more power, the more heat is generated. Speed costs, in both money and run time.

Note: never run a pack of really good NiMH cells all the way to dump - this will cause cummulative damage. Use a stopwatch and bring the boat in before it dumps. This is kinda like bringing a nitro boat in before it runs out of fuel....

.

[Tuslow1]

If you choose to run the 7 cell packs, Please let me know the results? I want to try it but I'm chicken to smoke it... If your esc survives the ginueapig test.. I'll do test Number 2

[Kirker]

Thus far I've been chicken to.

[Kirker]

Hey wait a minute!...Weren't you the one that got a couple "scratch and dent" ones for cheap! That sounds like a prime canadate for overpowering! And you have video to record it. Tuslow Tuslow Tuslow!

:wave:

[Tuslow1]

the first(red) one I got was for my son, and the wife wants the second(blue) one cause nothing was wrong with it other than the prop, rutter and one chip in the paint... But the kid would love to see his boat run faster... fine I'll go 7 cells on his boat... you know I'll post the results with Vid to boot... Man he gonna be mad if I fry it...lol we just went through hell to get it running right... I'll order up some good 7 cell sticks over the weekend....

[Tuslow1]

LHS says they got some but only in 1900 mah... I'm on my way

[Kirker]

Now there's a trooper!

:D

[SouthJersey-FE]

If you want higher speeds, rather than using 14 cells considering buying higher performance 12-cell packs. These will have higher voltages and lower internal resistance, delivering more power without over-volting the ESC. You will have to watch the heat though, the more power, the more heat is generated. Speed costs, in both money and run time.

Note: never run a pack of really good NiMH cells all the way to dump - this will cause cummulative damage. Use a stopwatch and bring the boat in before it dumps. This is kinda like bringing a nitro boat in before it runs out of fuel....

.
Wait so it's not good to completely drain a Nimh pack down?????? I was un aware of this.

[roadrunnerdude]

tuslow.
go to www.offshoreelectrics.com
they have all the products you could ever need for your boat and other boats.
plus they will build you a great batterie pack out of your choice cells. in any configuration.

you cant beat the prices either..

[Tuslow1]

ok fellow rc boaters the verdict is in... The LHS had 7 cells packs in but only in 1500 mAh hump and 1900 str8s, I got the long ones because of more run time.. Because they are longer they don't seat right in the cell slots but the velcro held them steady all the same... I was a little worried at first so I told my son to run it... The boat came up on plane like nobody's bitness and ran like crazy!!! From the looks of it my BJ 26 aint got a chance in hell to catch it, yes it is wicked fast on 14 cells... if not too cold tomarrow I'll do some vid.... Holy Cow!!! I think I need to buy me one now... and to think we were on the water for about 10 minutes before we even noticed a slight drop in speed from the 1900's... I think they should have sold the SV27 as a 14 cell only boat!!! and I checked for heat after we were done running it and the ESC had no heat and the motor was just warm, nothing to worry about... In this months issue of RCBM they said the ESC is good for up to 15 cells.... Whos gonna try LiPo's???

[Kirker]

Check these e-mails:
> Date: Thursday, November 16, 2006
> Time: 06:14 PM
>
> Question:
>
> A few of us have been wondering if we could run dual 7-cell packs in our
> SuperVee 27's instead of 6-cell packs. With 18 V, 45 amp hardware, theory
> says it would work, (2) 7-cell packs would equal 16.8 V. Other people say
> that would be pushing the ESC to hard. What do you think? Also, do you
> have any plans in the near future for making a "hop up kit" for the
> SuperVee 27?


Yes you can. The esc is rated at 14 cells. We have some 7 cell sport packs
coming in that we ordered especially for this boat with the 7th cell on top
of the 6 cell pack.
There esc is at its limits for new motor for a hop up kit. We have other
upgraded items, like adjustable trim tabs, better flex shafts, and better
cooling jackets for the motor.

Thanks
Steven Vaccaro
www.OffshoreElectrics.com

I'm gonna verify! :D
I'll keep ya updated!

[Tuslow1]

Me and my son are out running our speed test on the SV27 with the GPS, so far 23.5MPH on 12 cells but you can notice that the boat runs slightly faster without the Garmin onboard...
http://video.google.com/videoplay?docid=-2090926446037414243

[Tuslow1]

Once again you can tell it runs just a tad faster without the GPS onboard but on 14 cells the SV27 ran 27.6MPH!!!!! Today our pond had a tiny chop in it but other than that the wind was calm and the water was mostly like glass.
http://video.google.com/videoplay?docid=8620325396515361467

[Kirker]

Check out the latest e-mails:


To: "Steven Vaccaro" <stevenv@gis.net>
Sent: Sunday, November 19, 2006 12:47 AM
Subject: Re: OffshoreElectrics Contact


> Ok, so let me hear what your saying: Yes you can run your stock SuperVee
> 27 with 14 cells instead of 12 with no undue harm to the ESC (although I
> know it would void the warranty)? Purchase of a up-grade ESC is not
> necessary?
> Also, these 7-cell "hump" packs your making, what will they be called (so
> we can order them)? Will they be IB cells and will they be avaliable in
> 4,200 mAh?



The 7 cell packs are ib4200wc. We have to test the fit before we sell them.
I should have them in about 2 weeks.

Let me put the esc situation this way. The esc is designed for 8 - 14 cells.
BUT ANY time you push something to the limits
there is a risk in burning something up. The SV is a well designed boat, but
one little
leaf in your water pick at the beginning of a run and poof the esc and motor
are toast.
This is the risk we all have to realize. If we are not going to understand
the risk of running
fast, we have to step back to slower rtr boats that don't run on the edge.

I personally push the limits on our race boats all the time.Sometimes the
results are good, and some
not so good. Its part of trying to win races.

Thanks
Steven Vaccaro
www.OffshoreElectrics.com