Anyone care to school me on batteries? - RC-Monster Forums

Thirdgen89GTA · 12:53 AM

So, I've had the brushless itch for a while now. But it is a hefty price tag to convert, and honestly all of my RC sits involate because I'm just plain tired of glow plugs, and glow ignitors, bumpboxes, tuning, air leaks....etc the whole nitro shebang. The maintenance is getting expensive when its $8-$10 for a turbo plug here, and $33 a gallon for nitro there.

I've been helping my friend out alot lately on his new house. Tons of man hours, but he got an awesome deal on it. In thanks tonight, for an Christmas slash thank you gift he presented me with a MMM 2200kv combo for my truggy and a charger. I was blown away, its always been a tit for tat deal with us. We've always counted on each other to help out with projects, usually 1:1 car projects.

So as of the moment I have a Castle MMM 2200kv combo and a 6s traxxas charger. I know the traxxas charger is not the best. But being that it was a gift, and I didn't pay for it, I won't refuse it.

I'm a basher, I spend some time at the track, especially during winter, but its always open session and never racing.

Now though comes my lack of knowledge. I understand the whole Series rating and the C ratings, and how they work out mathematically. But I also have read about how MaxAmps has overstated specs. But I'm not sure what else to go with as far as battery brands go. I already know that my budget won't allow me right now to spend the $$$ on nice batteries, or even batteries that will let me achieve 55-60mph speeds for the run times I'd like. I have a budget of about $150 +/- a bit for batteries. Run time is more important to me, as long as I can reach 40mph or so.

The existing setup parts

Jammin X1 CRT Pro
Spek DS3 radio + servos
CC MMM 2200kv

Parts I know I need to order
RCM Jammin X1 CRT motor mount (still has the larger 62t spur)

Parts I am not sure on
?Batteries
?Battery Tray (single because of simplicity, prefer dual because of balance though) Can't buy this till I know what batteries I'm going with I guess.

I did a search for Jammin conversions, but rarely saw anyone use a twin pack setup for balance, is it just too difficult? Are there clearance issues, does the can hit the steering bellcrank? I measured out about 70mm and I think it'll fit that way if it mounts.

According to the Brushless setup guide this is what i get for a 10lb X1 CRT for a 15m runtime and ~40mph it recommends a 6s 25c 5000mah battery and a 10t pinion (read that the CRT mount may not let me use a pinion that small, can anyone confirm that?)

Quote:

Vehicle selected: Ofna Jammin X1-CRT
Differential Ratio: 3.31:1
Transmission Ratio: 1:1
Spur Gear: 62 tooth, Mod 1.0 pitch
Tires: 5.65" diameter, 1.99 lbs total
Base Vehicle Weight: 10lbs
Desired Top Speed: 40mph
Desired Runtime: 15 minutes
Selected Battery Voltage: 22.2V (6s)
Selected Brushless Motor: Castle Creations 2200 Note: If the motor and ESC chosen happens to be available as a combo, it is advised to purchase the combo rather than the separate components.
Selected ESC: Castle Creations Mamba Monster

Recommendations
Next, we`ll provide the recommended battery capacity/C rating, pinion size, and motor mount based on the above information.

Battery capacity & C rating (?): 5000mAh, 26C or higher (Click for technical information)
Pinion tooth count: 10T, Mod 1.0 pitch, 5mm bore
Motor mount: RC-Monster motor mount
Battery tray: RC-Monster vehicle-specific tray

Below are some vehicle-specific options, notes, and handy links to a few other items you may need:

Vehicle-specific options: (none)
Vehicle-specific notes: (none)
Be sure to check out our selection of battery packs and battery chargers.

brian015 · 12.18.2011, 08:16 AM

To go 40mph in a truggy, 4s is plenty - and will give you gearing options. So I don't think you need to use 6s for what you want (although you certainly could).

Will the CC Jammin X1CR buggy conversion kit fit the truggy? Or at least the battery trays? It's still available on clearance:
http://www.castlecreations.com/produ...sion_kits.html

For batteries, you'll get plenty of opinions. If you go with two 2s packs, these would probably my first choice (as a budget-conscious basher):
http://www.hobbypartz.com/98p-40c-50...se-direct.html
And you could get 2 sets of these on your budget.

E-Revonut · 12.18.2011, 09:01 AM

You will not get beeter balance out of dual packs, the motor and batteries come close to balancing each other out. Go to Hobbyking.com and get a Turnigy battery to stay in your budget. RC-Monster store also has some awesome batteries but they come with a bigger price tag. The Turnigy batteries will do just fine for you, 4s 5000mah would be a good battery. RC-Monster has some great battery trays so I would suggest ordering one with your motor mount, don't forget pinion gears, without doing the math I would guess about a 15T would be a good start, at least for the track.

Thirdgen89GTA · 11:26 AM

Quote:

Originally Posted by brian015

To go 40mph in a truggy, 4s is plenty - and will give you gearing options. So I don't think you need to use 6s for what you want (although you certainly could).

For batteries, you'll get plenty of opinions. If you go with two 2s packs, these would probably my first choice (as a budget-conscious basher):
http://www.hobbypartz.com/98p-40c-50...se-direct.html
And you could get 2 sets of these on your budget.

At the price of those batteries, I will probably just get 2 sets @ 6s. Thats well within my budget. That should satisfy my need for speed and co-exist with my wallet.

Quote:

Originally Posted by brian015

Will the CC Jammin X1CR buggy conversion kit fit the truggy? Or at least the battery trays? It's still available on clearance:
http://www.castlecreations.com/produ...sion_kits.html

Took a look at that kit, about the only thing that would fit would be the motor mount. The Truggy Chassis is wider than the buggy chassis, and so the mud-guards are excluded as the body meets the chassis with no gap, unlike the buggies.

Since I now know the size of the batteries I want, it makes it easier to choose a battery tray size. Looks like I'll be ordering the batteries, remaining parts.

I am finally excited to play with my RC cars again. They've been dormant for years.

Anyone want some nitro stuff?

I think the only tihng I'll miss will be the extremely cool nitro engine noise that a good 2 stroke makes when it comes on pipe.

I wonder how it will compare to my 1/8th buggy, which is currently the king of speed and acceleration. Still fairs favorably against all of the brushless combo's its run against. OS 30vg, JP-2 pipe, 30% fuel running a 17t CB and heavy duty clutch shoes it still 4 wheel drifts for a good 20ft mashing it from a standstill. Sometimes it wheelies too. The downside? Rip roarin' fun comes needs a pitstop after 8-10 minutes on a track, and bashing wide open in a field? 4-5 minutes if lucky depending on the tune.

The previous combon on the Truggy is a Novarossi 528XR hot-mods engine, JP-2 pipe, another 15t CB. Its almost as fast as the buggy but when the truggy falls off on the top end stopping at about 55mph or so, the buggy keeps on trucking to 62mph on the police radar guns. Its crazy how often the cops will stop in the parking lots and get those radar guns out.

Thirdgen89GTA · 01:08 PM

Much thanks to all. Parts are ordered. Now I just have to be patient.

Need to pickup some nitro cleaner. I stripped my CRT of everything and will be replacing all of the bearings as they are the original bearings from the MFG and its been several years. Might free up some power there if they are sticking/worn.

The wheels look horrid because I was in a hurry to get into a race and had to reglue them. Well, the superglue wasn't completely dry and as soon as it went out on track it was tacky enough to pickup all the clay and crap. So it was a messy and dirty glue job.

12.20.2011, 08:58 PM

Maybe these will help will some the basic knowledge of lipo batteries.

magman · 10:39 PM

If you only have played with nitro and never with Brushless set ups you are in for a treat. The electric version, BL, will be much quicker and more fun to drive.

A couple of things...

1. You will need to check your diffs for ANY play...eliminate the play with shims. Bl has so much more torque than nitro it will eat your diffs if not done correctly

2. your diff oils will change...in my mbx5t I run 20-100 -15 on a 5s set up and it rips. I only bash so I wanted to minimize balooning

3. speaking of ballooning, did you by chance tape the inside of your tires before gluing? If you didn't, next time to also help with pancake tires

4. try to keep your curse words to a minimum when you see the new power plant in action for the first time ;)

5. here is a link to a great resource tool.....provided by a moderator of this site....http://www.scriptasylum.com/rc_speed/index.html Just pick a category, plug in the appropriate numbers and you are off to the races

6. have fun!!!!

Thirdgen89GTA · 12.20.2011, 11:15 PM

Quote:

Originally Posted by magman

If you only have played with nitro and never with Brushless set ups you are in for a treat. The electric version, BL, will be much quicker and more fun to drive.

Quicker? yes. But not as much faster as many think. The only thing that held the buggy back was that I couldn't find a clutch that could hold up to the engines and gearing I wanted to run. I keep an old 21T clutchbell around as a reminder what happens when I try and exceed the ability of the clutch. Its coated with aluminum and filled with melted chunks from the 7075 aluminum shoes I paid $40 for and only got a single night out of. I was trying for 21/48 gearing it couldn't take it :(
http://home.comcast.net/~thirdgen89gta/rc/21t_cb.jpg

Quote:

Originally Posted by magman

A couple of things...

1. You will need to check your diffs for ANY play...eliminate the play with shims. Bl has so much more torque than nitro it will eat your diffs if not done correctly

That had to be done with the old Novarossi 528xr that was modded. I never stripped one, but the wear after a single season with that engine was crazy.

Quote:

Originally Posted by magman

2. your diff oils will change...in my mbx5t I run 20-100 -15 on a 5s set up and it rips. I only bash so I wanted to minimize balooning

3. speaking of ballooning, did you by chance tape the inside of your tires before gluing? If you didn't, next time to also help with pancake tires

Tires are already taped. Actually not tape. Cheese cloth with rubber cement is what i used because ductape couldn't take it. Essentially the same process as you'd use on a lexan body.

As for the differentials its already "brushless like" with 50k front, 100k center, 20k rear.

Quote:

Originally Posted by magman

4. try to keep your curse words to a minimum when you see the new power plant in action for the first time ;)

I miss insane stupid fast stuff. I haven't played with the cars in a long while because they got so out of tune, then the glow plugs fouled out from sitting for so long...etc. Brushless will make things easier.

This is my next conversion project, a Hyper One Seven Evolution. Based on the Hyper 7 chassis with its awesome pillowball suspension, but its super stretched coming in at 30" long. See the link in my sig for a size comparison. But here is the H1/7 next to the Jammin truggy, an Inferno GT and itself.

Look at all that wonderful room for Lipo's in that chassis. :)

_paralyzed_ · 12.22.2011, 01:58 PM

Hey 89gta: I'm a brushless guy. I have a buddy that insisted on putting the biggest motor he could find on his 1/8 buggy. Now he has a surefire .32 in his buggy.

Any recommendations on gearing or other setup advice? It has a 48t spur. I take it from your previous post not to try a 21t clutch bell!

Thirdgen89GTA · 12.22.2011, 02:57 PM

Quote:

Originally Posted by _paralyzed_

Hey 89gta: I'm a brushless guy. I have a buddy that insisted on putting the biggest motor he could find on his 1/8 buggy. Now he has a surefire .32 in his buggy.

Any recommendations on gearing or other setup advice? It has a 48t spur. I take it from your previous post not to try a 21t clutch bell!

I could happily run with a 17th clutchbell all day long using OFNA blue shoes and OFNA gold springs on a 3 shoe setup. But they would only last about 2 months being about 8, 8hr bash sessions. If I didn't drive the car much they'd last much longer.

Aka, the shoes my buggy has now with its OS 30vg engine are the same shoes its had for the last 3 years and they still hook strong, but they don't look much like the shoes I thought they were anymore.

I did some special prep though. I'd rough the inside of the clutchbell up with some 400grit sand paper to increase the bite. I used ceramic clutch bearings and a vented clutchbell to help town down the heat.

I once temped the clutch bell at almost 315* F before I figured out the gearing, clutch setup and prepwork.

The thing I most went through though was bearings. The clutch bearings would constantly wear out due to the massive heat. The Ceramic bearings were expensive but they lasted a long time so it was worth it.

The buggy is the following:
Jammin X1 FTE
OS 30vg engine bump start version.
Jammin JP-2 pipe
Vented flywheel
17th vented CB
OFNA blue shoes
OFNA gold springs

The above setup was good for hitting 55mph. But it was a gas hog, running wide open in a field resulted in 5 minute fill-ups with a 125cc tank.

_paralyzed_ · 11:08 PM

Awesome advice. I imagine it will be a gas hog. I've got an o.s. .30 in my LST. I preferred it for it's ease of tune compared to the surefire .32 I mentioned, that's why I sold it to my friend. The o.s. had all the power or more of the surefire. o.s. makes a damn fine nitro engine.