which dual cell should i do, laymans, external, internal etc
 

I want to do a dual cell mod to my spare bit charg 2 speed.
I have two stock batteries right now, and i was planning on using them with a new 2.2 i have. I also have a spare new 4.2 but that seems a bit much for a dual cell. I will try it though.
I want to do an internal dual cell, but i think there are too many risks involved with that. I have heard that the laymans dual cell is good, but it has less ?amps? How does that affect the way the car will perform?
I might just do an external dual cell. I know how to do it, ive read quite a few tutorials on it. How much will my car roll with the cell up high?
My MS pro has the full pullback wheel mod, i could always take those tires and rims and put them on the dual celled car.
Or i could just use the stock tires, or i could do a fullsize wheelmod. I will do whichever doesnt flip too much.
I kinda want to keep the pullback wheels on my MS pro so i can still race with my friends with that.

So, should i do the internal dualcell(im afriad to do this) the laymans dualcell, or external?
And how much will the car roll with the external dual cell.
And what are the cons of the laymans dual cell vs the other two?
Thank you!

bump.
Will I always roll over with the external dual cell?

i havent done a dual cell but with a 4.2 in a single and stock tires all around i flip every turn so i'd assume so

but the harder tires give it a larger turning radius so you should just not be able to turn as sharp

The 4.2 with a dual works well, although I think I actually prefer the 3.8. But, in a booster car, I would only use the 4.2 pro. That motor will last longer in a booster. I've killed many a motor with a booster car.

I would absolutely, positively, only recomend an internal dual cell. If you get the batts low enough in the chassis, then it wont flip unless you hit something at the right angle to make it flip.

I've made a small army of internal dual cells. I've perfected the technique.

The picture is just a rough draft of how I do my dual cells. "A" is where I take out a rectangle piece of plastic, so there is a hole in the bottom of the bit. You'll have to make the hole just big enough to set the battery in it without the battery falling through or touching the ground. "B" is where I cut a chunk out of the wall that seperates the motor compartment from the battery compartment. That's not an exact science, just cut so it will sit back farther. I usually have to cut part of the cars right motor compartment out some. Don't cut both sides cause it might make it weak. I'll put another pic here about that. "C" is The wall part that I cut. Note that you an't cut too far down because you'll cut into where that back axle sits. And, you can't cut too far back, because you'll cut into where the middle geer's bar sits. Just go slow and be patient the first time. If you get it right, then you'll have a car with good balance, speed, and control.

I almost forgot. The red outlines are where the batteries sit.

And yes, the leymen's mod is a good mod, but lacks the amps to get the car up to it's full potential. So, a dual cell with 2 stock nicads will easily beat a laymen's mod even if the laymen's had 3 batts in it. I'm not sure about the laymen's with more than 3 batts, because I've never put more than 3 in a car. But I've heard a lot of people mention that a laymen's mod above 3 batts doesn't offer much increase in speed and lowers control value beacause of the extra weight. I also didn't notice much of an improvement from 2 cell laymen's to 3 cell laymen's.

Alright thanks, i guess i will do the external dual cell, then if i dont like it i will try to do the internal dual cell.

External isn't too hard, and you wont risk messing up the car. You'll want to get the extra batt to sit above the back wheels (I think) for balance.

I have a diecast ambulance that's top heavy. Most of the weight is in the back. I use oil coated slick tires. I loose acceleration, but it never flips. Besides, it's a diecast ambulance. I don't really care about acceleration with that. It might beat a stock. It is dual celled (internal). Although, I could always just try and kill the competition. It could probably knock a regular bit way off the track with a good hit. It's like a hot-wheels car frame that I dremmeled out to fit a bit. It's pretty heavy. Anyways, happy modding.

Also, if you are worried about damaging the inside, here's what I do. I disconnect all the internal wires, except the steering wires, from the chassis. Most of the wires, with the metal contacts, can be pulled out one way or another. Unscrew the steering comartment. Take all the pieces out of the steering compartment. Now move the PCB to the front of the car and secure it somewhere at the front of the car with a piece of tape or something to keep it from moving. The idea is to get the batt compartment free of all wires, so you don't risk damaging them. Now you should have a good clear space to dremel/cut away. If you cut too much, there's always duct tape and superglue. That fixes anything.:rolleyes:

The external isn't too bad. I think the internal dual cell on a bit chassis flips almost as easy. Heck my mosfet modded, single cell cars w/ pullback wheels flip if you hit the corner fast enough, anyway you go about it, you have to slow down for the the corners.

And the external gives you the added bonus of popping wheelies, if that's your thing. If not, then it only does it when you reverse it, then slam into forwards.

Actually, I'll have to admit that mine still flip sometimes on carpet. If I run them on a good flat suface like wood or cement, then they never flip.

I will do this sometime in the future, im too busy with school starting tomorrow and im working on my eagle project for boyscouts.

Heres what I'll be doing soon:

As is (current car specs):

-MS Pro
-4.2 Pro
-Stock gearing
-200mah single cell

Will do in close future

-Laymans Tri Cell
-Mosfets
-Wheelie & rollover bars (will be needed :p)



As is this car goes about 4mph, so wit these upgrades it should go...fast;)