R/C fan-addict

Hey guys, so I'm in the process of purchasing my next R/C which will be a jammin crt.5 pro roller. I'm using the RCmonster electric motor mount and a tekin battery holder. I'm buying the truck used from an RCU member so as far as I can tell from the description the battery holder was used for 2s packs, but it looked like the edges were bent in to hold the pack from sliding forward and back, but I think I can just bend it back out and mount 3s packs which I plan to run. So I will be using a Castle Creations sidewinder ESC for this truck and a TBD motor (any suggestions?) Originally I was thinking to go for the 5800 on 3s, but I've heard that it doesn't do so well on the crt.5 since it does get a little heavy after all the electronics are on board (a lightweight one might be 4lbs, but that's probably using a 2s pack, they can get as heavy as 4.5 or 5lbs! [X(]). I also want to try a different motor from all the well known R/C manufacturers are try perhaps something like a feiago or other... anyway, this post is about batteries so I'll cut to the chase. I want to run 3s, with 3000mah+. That's really the lowest I'm considering, since I want good runtimes and I only want to get one pack, leaning more towards 4500ish budget permitting. I'm willing to spend about $100, perhaps a little more if the cells are really nice, but I'd prefer to stay below $100. And the further under that mark the better, for a quality pack that is : )
I've also been hearing a little that the maxamps packs are not such good quality, I would prefer to have 25c discharge rates over 20c, and the maxamps packs are way too expensive. I would be able to solder a pack if it's considerably cheaper to purchase loose cells. I have a duratrax ice to charge em with, and the heat sensor too, so I think I'm pretty safe for charging the packs. Never the less I will charge them in a metal box with a vent fan. I looked at the lipo sack but it's expensive and I think a metal box works just as well. Now for balancing and cutoff. The sidewinder has "programmable" cutoff, but does that mean you need the castle link to use it? In which case I'd probably just get a mamba instead. Then for balancing, is this necesary or just a performance thing? Also what is a good balancer if they are necessary, no more than $40 please. Alright that's a long enough post. Thanks in advance for any help : ) I'll post up some pics when I get the crt.5 and some videos of it running! It should be a blast!

-R/C fan

GravityJunkie

My electric crt .5 is near 4.5lbs with a 2s 3800 Limn pack.

As far as balancer, there are both sides of the argument. You can get a blinky balancer for somewhere near $25 (if I remember right). It'll balance them fine. It'll balance voltage to keep things in check, which could help performance. As to if you need one or not, this issue has been discussed many, many times. Do a little research and decide for yourself. I personally balance occassionally, just because I've got a blinky already. Things are usually pretty good. However, I'm running matched cells from Apogee. Even with cheap lipo packs, after the first balance or two the packs stay fairly balanced. However, I have used my blinky to bring a pack back from the dead, so that alone paid for it.

Do you have a link of the CRT you bought. I'd like to see the battery holder. I don't care for my current setup, but it really was only a placeholder until I decided what I want to do long term.

Oh yea, I'd recommend a liposack. It's only $25 bucks on Tower, and you could use a coupon to get it cheaper. I've seen vids of lipos going up in cans and liposacks. The liposacks seem to contain it better, they are more portable than cans and aren't conductive to electricity like a metal can. And probably the biggest reason is that our track states that anyone charging a lipo must do it in a liposack...

sloppyG

Hi there, it's my roller he's looking at I've got some pics up in my gallery



I have a 3s 5000 mah maxamps pack that I used in there when I used to use a 9L motor in there (2700 kv/rpm), when I swapped to the medusa (4800kv/rpm) I went down to using 2s packs

here's the link to the battery tray I used http://www.neweramodels.com/item.cgi?part_id=1952

GravityJunkie

Thanks sloppy. How'd you like the Medusa motor?

R/C fan-addict

alright, so if you're running the medusa on 2s (are you satisfied with the acceleration and speed?), then I think I could run the medusa on my GTB. That on some 2s cells would work nicely. I'm also thinking that a 2s pack is more versatile for me since I can run it in my TRF415 and some of my other trucks just for fun. The 3s would be exclusive to the CRT.5 and the mamba esc. I was looking at the monster maxx, and thinking that I might want to get one further down the road, in which case then I could run the medusa on 3s, and perhaps get a neu for my emaxx and savage [>:]... ah just day-dreaming But I think for now I'll do 2s on my GTB and run the medusa 4800 k/v. I'm sure I can gear it higher than a brushed motor at 35,000 rpm since BL has more torque so speed will probably still be in the mid 30's+. That way I stay below $300 too which is always good. Sloppy, you got PM ; )

rschoi_75

If you plan to run 2s, then I'd suggest the Neu Energy 5000mah Hardcase lipo. Top of the line quality and at a very good price.
http://www.neumotors.com/20061222/Car_batteries_.html

R/C fan-addict

hmmm that looks very nice! I might go for that one! Just have to get the truck first, then start getting parts for it!