battery ??'s

[BigSki]

I'm ready to take the next step into making my rig a better comp machine. I need to use the front axle mounted batt packs. I plan to but them from cheapbatterypacks.com, but I honestly know almost nothing about what I need.

I've tried to read different threads from the search button, but I'm still really in the dark. I'm running the Rooster Crawler 55t motor/ ESC combo, so I don't want to fry that thing. Do I use the 2, 3 cell packs or the 4 cell packs? NiMH or NiCad? I really don't know anything about LiPo, so I'm not comfortable with even thinking about using them yet.

I have the basic, entry level 15 minute 'quick charger' for charging the stick packs right now, but I don't have any problems upgrading to a better quality charger.

Thanks for any help!

[BigSki]

should I have this moved to the electronics section?

[nuts5000]

if your running them on the front axle (servo in the middle)
then get the split 4 on one side 3 on the other..
you will like the 7 cell's

[BigSki]

thanks for the reply. A 7 cell pack puts me at 8.4 volts, right at the limit of what Novak recommends for the rooster setup. Is that going to cause me any 'melt down' issues?

The next comp is Aug 10th, so I only have a short amount of time to get parts and get everything dialed in.

[Georgerm]

the rooster will be fine at 8.4 volts. i do not think you will be able to charge the pack with your charger.

[BigSki]

good point georgerm. Maybe I should just go with the twin 3 cell packs, my cheapie charger will handle that.

[WVB]

If you plan on comps - then don't cheat yourself... You will be much happier with 7 cells. Also I noticed TCS states not to charge their pack higher then 1.5amps. I would check with your charger to see what the output is. CBP's sells the same cells (elite) as TCS so I would imagine that the charge rate would be the same...

[thetoptanner]

If you are gonna run packs on the front axle here what to do.

Check to see how many cells your esc can handle.

If it handles 8 use 4 cells per side

If 7, use 3 one side, 4 one side

if 6 use 3 per side.

Make sure you get the 2/3 A cells. Subs C cells are too big for the front axle.

You will need NIMH cells and a NIMH charger that charges about 1 AMP.

Some places say more than 1 amp for charging but just to be safe I go 1 amp .
Better safe than sorry right?

[bnoland]

I would also get you a good charger. I had a cheap one and it was killing the life of my batteries because it wasn't peaking correctly. I got the ICE charger for my birth day and it is much better and I am getting more run time from my battier because they are being charged properly.

[p01rogue]

don't be afraid to consider lipos.
Do a little research on them.
They are very safe and stable nowadays as long as you follow a few simple rules.

[nick f]

I have a question to ask. So everybody adds weight to the rims of the AXE (whether it 6-10oz per rim) and then goes and uses the 2/3 AA batts over the axel. If I wanted to run a custom sub c pack over the front axel, kind of an upsidedown "U" shape over the steering servo and not run any weights in the rim, do see any potential problems. Too much weight total? Weight not in the lowest position possible?

I know some people have done this before and the reason I ask is this. Are we losing some torque (power) running the 2/3AA cels instead of the sub C cells. Under heavy load are these 2/3 AA cells up to the task?. The best cells I've seen are 1.26v and 1800mAh. At 20c that s only 36 amps. I'm sure that a 45-55t lathe motor can pull more amps than that close to stall.

Any input, thanks

Nick F

[nick f]

Ttt

[j33pownr]

Running the upside down U will effectively raise your cog because the batteries will be higher up. Also removing the wheel weights will raise your cog as well. The U shape is deisreable from a quickly replaceable dead battery because its all one pack but the split packs put the weight where its needed, low and at the corners.

The sub c's are pretty light and if you remove the wheel weights as well, you wont have much weight over the front axle. How much weight you need over the front axle depends on your driving style and type of terrain. Its mostly personal preference but the general consensus is like you said 6-10oz in each front and 0-6oz in the rear. I personally have it more ballanced than all in the front because we do back up hills as well as climb them.

[goldmember]

I just purchased an Axial that came with ther upside down U sub c pack on the dront axle. I'm really not impressed with the weight dist. My truck is running the Rooster crawler combo and I have a great charger. If I switch to the 2/3AA split packs from TCS, how many cells can I safely run? 6, 7, or 8?

[BigSki]

thanks for the informative replies. I ordered a 6 cell pack from RPPHobby. Corey just started to carry them, he was actually unpacking the first shipment while I was talking to him, ordering more part$ for my AX-10.

I got MaxAmp 1600MA cells, they are already wired w/ the Deans connenctor. 2, 3 cell packs. Most of the guys at the last comp were running the same type of setups and everything seemed to work well, so I'm going to give it a try. The Rooster ESC claims a max voltage of 8.4 volts, so I'm in the safe zone with this setup. If it turns out that it isn't enough, I can always add another cell into each pack.

[goldmember]

Now I'm confused...what kind of charger do you need for 2/3a batteries? I was thinking these saddle packs were the same as my current battery pack just split differently.

[71CutlassS]

Goldmember, way to hijack the thread. You said you have a "great charger". What is it? If its anything decent it should charge a 2/3a battery pack split or not.

[goldmember]

I apologize if I hijacked, but I was talking about the same packs Bigski was. I just had additional questions.

I just sold my MRC977 charger as I had trouble with it and picked up a two Duratrax Onyx 230's. But I am new to the hobby.