Dual BL on a single Lipo?

Hey guys, great board here! I have been lurking for some time waiting for the right question to ask and i finally have one.


I have a ClodBuster that I have setup for racing with a new setup for our club, dual Sidewinder 4600's! The thing moves really well and the power I am achieving with this setup is great but the weight of 12 cells (two 6 cells run in parallel) is an issue. Im looking at the possibility of running a single lipo in the truck to lessen the weight but is there a pack out there that can handle the draw of two motors like this? Im still new to the lipo scene so Im not sure what direction to take. Im not looking for crazy runtimes. The longest the truck will need to run is during the 4 minute lap racing its setup to run in. Im also not looking for a rocket ship.. the performance on 7.2 per motor is perfect I just need to shed a few pounds. So a 7.4 pack is definitely in order.


Will something like a Maxamps 2s 8000Mah pack would be my best bet? Or is it not enough to power the 2 motors? Also could it be too much.. would I be fine with something like a 2s 6000 pack?


Any input here would be awesome. Im trying to get this badboy setup for its first event this upcoming August.


Some pics of the setup as of now:

[What's_nitro?]

Dammmm! How much you want for that thing!!! And/Or what chassis is that? It's really nice looking...

I'd get the 8K pack if you can fit it. Or the 10K pack...bigger- yes, heavier*- yes, $50 cheaper- YES! No question about enough runtime? Priceless.

*Still loads lighter than a 2p Nixx pack- yes!

[Topspeedtimmy]

I'd recommend a Flightpower 2s pack . Lipo pack that isn't over-rated and they have awesome performance, the MA packs are questionable with continuous discharge ratings... might not be able to handle dual 50 amp motors. This pack will save you 20oz. and it should run for 20 min

[Takedown]

I 2nd the decision of a 2s flightpower.

[What's_nitro?]

You know, for $120 the FP pack looks pretty nice... Any idea of your average current during a race? Errmmm nevermind, you'd need an avg. current of 75A to kill that 5K pack in 4 minutes! Go for it!

Awesome. I have that exact pack in stock at my shop.


I was also looking into these packs, http://www3.towerhobbies.com/cgi-bin...&I=LXULS3&P=ML . Does anyone have any experience with them? I only ask because the track preffers a pack with some kind of hard case around it. I can whip something up for the FlightPower pack if need be but I have heard good things about the SMC packs as well.

Will I need to worry about any heat issues with the FlightPower pack after the full 4 minutes of racing?


As for setting up a LVC, should I use an external unit that is hooked up the the "Y" harness coming off the pack to the esc's? Im not quite sur if using the cutoffs built into the esc's would be a good idea but that being said I really have no idea at all.


Sorry for all the rookie questions but man do your guys know your stuff.


BTW, the truck features a ThunderTech ripper chassis with mostly stock clod buster geaboxes on it. Ill post some more detailed build pics and videos of it once I get the lipo cranking.

[traxxasrevony]

the fp back would be a good choice


i see someone likes crosby.

im a rangers man myself

[Topspeedtimmy]

The 125 amp pack has plenty of power, so it should not overheat. As long as you set the cut-off the same on both ESCs they should both work just fine. I don't know what cells SMC uses, but theres a chance they're lower quality than flightpower, which has enerland cells. You can get 2 of these Trakpower packs , wire these in parallel and you will have packs with a hard case, 128 amps, and 6400mAh capacity for $30 more. It will only weigh 4 oz. more, which is still light.

The TrackPower packs look pretty sweet too. Ill try this FlightPower pack out first since its readily available and you guys have helped me with any of my "unsureness" of the setup.


Should be running by this weekend.

[rootar]

FYI... Flightpower makes/owns Trakpower lol they are they same id say go with their hardcased trakpower pack the batteries sit low and vurnerable on the TT chassis so the hard case would be a big plus for your use.

I figured that was the case, but Im really just trying to stick to one pack for now. If it gives me any issues Ill swap to the double packs. The battery is shockingly well protected in the Ripper chassis when its run down the center instead of the conventional cross mounting. Being that the truck is only ever raced on carpet tracks its never gonna get hammered on too hard.


I was thinking of picking up some lexan and making a partial hardshell case like the maxamps skin to surround the pack with just in case.

Well I finally got it all setup and wow, does this run awesome! Took a little time to make up a lexan hard shell case for the pack before I took it out to run. Its more or less a tray thats shrinked around the pack. Does the job well.

It won its first race 2 weekends ago in a pretty impressive performance. The power was just unreal and the weight savings was very noticeable. Im getting superb runtimes from it as well. Easily over double what I had before.


Here are some pics of the setup. Thanks again for the help!




Warming up on the track.

[suicideneil]

Awesome. Had a TXT once, but had to let it go in favour of the maxx.

I dunno if you figured out the LVC thing yet, but it would in theory be fine to set both escs with the same lvc setting (say, 3.0v per cell, or 3.2v). Since they are both sucking power from the same battery, the voltage they read will be the same, so when one lvc trips on one esc, the other will too- stopping the batt from over discharging.

That said, you're making me jealous with that ripper, nothing like a solid axle truck for scale awsomeness. Post a vid if you can, I wanna see that thing in action

[Takedown]

Looks sweet! I was wondering when you'd finish this up.