View Full Version : electric r/c boats


Kirk
08-13-2006, 04:50 AM
I am a disabled person, wheelchair bound and decreased motor skills, but I love r/c's, ecspecially boats. I would love a gas boat because of the power but with my limited fine motor skills I just can't physically do the constant and detailed tinkering that is required of them. Thus, electric seemed like the better option for me. I have a rtr, hobby shop bought, electric boat now and it's pretty cool but I'm ready to move up.

My question is can you have modified/have built/buy a electric boat that is fairly bad a**? I know it won't rival gas but say 20 mph+? If so, where would you start? Would you buy a good rtr boat and go from there or would it be better/cheaper to start from scratch (remember, I'd probably have to pay for the labor)? What are the most important aspects for electic r/c performance? Am I just barkin' up the wrong tree altogether?

I don't want to be a pain in ya'll's rear, I just want to enjoy the sport the best I can given my situation. Therfore, ANY and ALL advice/tips would be appreciated. Even if that means tellin' me to find a way to make gas work or tellin' me to hang it up altogether and take up cheekers! :o

Thanks in advance,
Kirk

nomobux
08-13-2006, 08:50 AM
you mite go to Tower Hobbies and take a look at the Aqua Craft line. They are RTR and affordable. Use good high cap batts and a good charger. I have their Reef Racer and it's a fun lil pond boat. Also, self righting.

trackman
08-13-2006, 09:34 AM
What do you have now???

Does it us AA /AAA or sub-C pack batteries ???

How many batteries in the pack??? ( pack voltage )...

What size electric motor is in your previous boat???

When you say step up ,what will you be stepping up from???

There are different size electric motors 180 ,280, 380, 540 , 550, and probably some I missed...

If your system now uses AA or AAA, you could move up to a sub-C battery system and use bigger motors... Another alternative is to add more cells to the battery pack for more voltage...

OvalTrucker
08-13-2006, 11:43 AM
Kirk,
There's plenty of things you can get to enjoy r/c boating. I would stay with electric though unless you have a buddy that can help. If a nitro boat flames out in the middle of the lake, you'll probably need someone to help retrieve it. With an electric boat you will notice the battery going down and be able to get it back to shore.

Faster motors, bigger batteries/more cells will make them faster.

Check out www.towerhobbies.com like nomobux said.

Kirk
08-14-2006, 12:06 AM
To answer Trackman's question, the boat I have now is by ABC Hobby. It is has a 550 motor powered by a 1500mAh, 6-cell battery. Like I said, it's pretty fast (14 mph) but I'd like to fillet a couple trout while I run! On the battery thing, a guy told me if you get the upgraded batteries all you really get is a little longer run time but power is about the same, any comments? The cell idea is interesting. Do they make battery packs that are more than 6-cell?

One boat I was looking at is by Traxx. It's has twin 550 motors and needs 2 battery packs. Two motors, two batteries but also more weight. Do you think I'd see much difference in performance?

Thanks to nomobux and OvalTrucker for turnin' me on to Tower Hobbies (man do they got alot of cool stuff on there). Their 'mac-daddy' boat right now is a single prop AquaCraft. It has a B36-56 motor pushed by two battery packs. Is a B36-56 a fairly high end motor? Is it badder than a 550? The two battery packs, is that a run time thing or does a B36-56 need two batteries to push it?

Thanks in advance for the input,
Kirk

P.S. Nice pic on your profile there OvalTrucker!

hockeyman2
08-14-2006, 03:32 AM
traxxas boats

SuperXRAY
08-14-2006, 11:40 AM
Kirk,

Traxxas makes good RTR boats, but they really aren't the best performers. A professional boat will cost you more and require quite a bit more assembly time. That decision is all up to you. As for the 1500mah batteries and what someone told you...You can get 3800 and 4200mah batts now. Along with having better discharge currents, they will last longer, no doubt. You don't quite get a linear 'run-time' curve, but it is close, so a 3000mah pack will last almost twice as long as a 1500mah pack if kept in good condition (using a good charger and storing them properly).

Although I am not a boater, I have friends that are, and rarely do I see them running 6 cells. Most run twin motor, twin battery combinations of 14-28 cells total. Because of the strain of boats, I would look into a brushless system with a good boating speed control that will let you run whatever number cells you want. It's all about money and what meets your demands.

I hope you enjoy whatever you get! I have a friend who is quadriplegic who races nitro monster trucks with me and he loves it. Doesn't do half bad in the sportsman classes either. :)

trackman
08-14-2006, 02:34 PM
Kirk ,

The number (1500, 1900, 2400, 3000 3800 and so on )mah on the battery is considered to the run time when drawing a particular amp from the battery pack ,Such as a 1157 taillight bulb draws approxmately 2 amps for a certain length of time ...

The voltage is accummilated with how many cells you have in your battery pack... Such as 6 cells equal 7.2 volts , 7 cells equal 8.4 volts , 8 cells equal 9.6 volts ... A single cell rechargable aaa/aa and sub-c battery has 1.2 volts , where as a standard alkaline battery has 1.5 volts ...

But when using more cells for more voltage there is a faster draw of charge on the battery ... For example , A 1900 7 cell battery pack will give you more voltage and speed, but run time will be roughly equivalent to a 1500 6 cell battery pack ...( being used in same conditions and circumstances)...

There are two ways to say it; SPEED COST ...#1. How fast do you want to go???, or #2 .How much do you want to spend??? They both say the same thing!!!

Most standard esc's can handle up to 7 cells , and some can run more cells than that ...Check description before your purchase ... ESC's also have certain motor limit's such as size of motor ,how many motor's and number of turns in the motor...Also check those descriptions before purchase ...

Then your charger(s) has to be able to charge these battery packs ...
If you have twin motors you will also need 2 like battery packs charged at the same time...

The MRC super brain 959 battery charger can charge up to 8 cells AAA/AA and SUB-C (we find this charger to be a great all around charger )...

Kirk
08-14-2006, 06:42 PM
Thanks for the input SuperXRAY and trackman. I think I'm getting it, more cells = more power but burns a charge faster. Just like a supercharger on a car, more hp but burns more fuel, makes sense.

Ya'll mentioned ESC's. One boat I'm looking at is a single motor powered by 2, 6-cell batteries, the ESC is 45A. If I ran 7-cell batteries in it instead of 6-cell, do you think a 45A ESC could handle it?

Trackman, on another thread I saw you recommended a Digitrax digital peak charger, you also mentioned a MRC-959 which I noticed also has a digital readout. Is a digital readout really that important or does it just look sexier?

Over and over I read people saying get a 'good' charger. What constitutes a 'good' charger from a 'cheap' one (other than price)?

I read somewere about the pros and cons of Ni-Cd versus Ni-MH batteries but I can't find it now. Anybody want to give me the cliff-note version, pros, cons, fish stories, etc.?

Thanks in advance, ya'll are awesome,
Kirk

trackman
08-14-2006, 08:25 PM
Hey kirk ,

I think your talking about the 45 amp 18 v system with the b 36-56 brushless motor...

Amps would be what the motor is drawing and would probably draw that amperage whether it was 6 cells x 2 (12) or 7 x 2 (14) cells ...

I believe that esc can handle 18 v which would be up to 15 cells...

The mrc 959 and the duratrax digital peak piranha charger are both versatile and a very good buy for both Nicad and MiMH batteries ,AAA/AA and SUB-C batteries and both will do up to 8 cells ...

The MRC 959 will charge up to 8 cells at up to 4.5 amps on it's own without a power supply...

The digital piranha peak charger is a little more versatile on manual settings and will charge up to 8 cells ,(I believe it to be a little better charger than the 959) but it will charge up to 6 cells at up to 5.0 amps, But here is the catch , When you are charging a 7 or 8 cell pack with this charger it will only do so at 3.0 amps or less unless you buy a 14 volt power supply with at least 5.0 amps per charger you want to use ... When looking at power supplies you need to look at voltage and amps... For instance we have 2 novak N- power amps that each have 14 volts @ 10 amps each... We can run 2 digital peak chargers on each one of these ...

But then again you could look at the the Mrc 989 >>> I do not know any thing about it but it will do up to 25 cells Nicad and NiMH and will do Up to 8 cells lipo if you ever decide to go lipo...

To me a good charger should be a peak ,versatile, adjustable, linear charger capable of charging Nicad and NiMH batteries (Some prefer the new Lipo batteries but to exspensive for me) ...

Nicad 's to me are becoming a thing of the past due to less run time ( lower MAH) and are to me a little more maintance and are more pron to getting a memory ...By memory I mean a 1500 mah battery can easily become a 1000 or 1200 mah battery if you do not maintain it properly ...

You will need somekind of discharger for battery maintanance weather it be NiCAD or NiMH battery ... And also remember when drawing 45 amps, that amperage will melt a standard tamiya battery plug ... You would have to go to a better battery plug like the w.s. deans type... I also believe at that ampreage draw you can forget using NiCAD's and would have to go with a battery that can handle that amperage draw...

baih
08-14-2006, 11:49 PM
i have a traxxas villian ex. since its just for fun it works good. but i leave it stock because i can get parts from traxxas. but there are so many brushless motors now i might go to brushless motors.
http://www.aeromarinerc.com/
http://www.offshoreelectrics.com/MainPage.htm
http://www.funrcboats.com/category.aspx?categoryID=40
http://www.bbyracing.com/
http://www.hobby-lobby.com/ this site also has jet drives for boats.

check out the locations for the boat races. the one here in south el monte has an area just for r/c boats
http://www.namba.com/content/schedule.asp?RaceID=19