Losi 7.4v 3300 mah 20c lipo - thoughts?

[honyock]

Could this bat give decent performance and run time in a 4ws MOA rig with Novak 55Ts and HiTEC HS5645MGs? Also, it has an FXR with CC BEC. All tied to a PunkRC computer. Oh yeah, it weighs about 8 lbs. Bullies.

I posted a thread about wiring everything together for this project elsewhere here, but no follow-up rec'd

Just wondering if this battery will do what I need or if I should give up the idea of getting a small footprint lipo in the VP chassis.

Not competing or anything with it, but I'd like it to perform well.

Thanks

[atekt]

Im pretty sure I have the battery you are reffering to, It will definitely provide you with enough power and runtime. My only gripe with it is, its size. Its pretty bulky.

[honyock]

How so? The reason I ask is, I want something that fits in the space just above the bottom of the skid plate on the VP Incision chassis. That's about 100mm long x 50 mm wide... then i've got 25-30 mm height under a lexan tray holding my FXRs, BEC, and the Punk computer.

I know this Losi is around 31 mm high, so if there's something comparable in length/width but shorter height... with the same performance capabilities... that'd be great.

Thanks

[indiana mudcat]

i run that battery on my front axle, great run time. other than it's thickness it's smaller than the 1900 or 1250 pack i got and i notice the added amps from those packs to.

[bigflex]

waist of money! There is a lot better batteries out there for less money.

[JeremyH]

Originally Posted by bigflex

waist of money! There is a lot better batteries out there for less money.

Agreed! ThunderPower makes excellent batteries.

BTW, I used to drive through Dimebox a lot going to and from school!

[nismotuningrocks]

the losi batteries have too low c rating for the price, buy a hobby king battery with 30 or 40c for less than half the price and be happy

[phillyb]

I have it as well, not sure how you guys are running it on the axle though, maybe with offset or narrow rims. It works well, but I agree with the others here, its fairly pricey. I noticed a huge difference in power between it and a 7.4 TP 1300 pack. I run a 3 cell TP now though.

[honyock]

Phillyb,

Which TP are you using? Is it similar in form factor? (<100mm x 50 x 30)

Are you using it with the FXR? I've seen discussions elsewhere here that make me think Tekin's support for 3 cell is mostly informal.

All,

Thanks for the feedback. I'm going through the TP offerings and definitely liking the price differences I've seen. The big sticking point seems to be the amount of "ooomph" I can get in that small of a unit.

There's a 'military grade' TP -- the rc pro lite ms 2000 7.4 2-cell 2s -- that I have my eye on...

[JeremyH]

That "oomph" that you're wanting will come from voltage....not mAh. A 3S lipo will really liven up your crawler (just make sure that your ESC can handle 11.1V). Increasing mAh will simply increase the runtime of your crawler.

I run the TP 1350mAh 3S on my Bully (dual motors) and it will fly! The battery will last about 30-40 minutes depending on how much throttle I use...

[phillyb]

Originally Posted by JeremyH

That "oomph" that you're wanting will come from voltage....not mAh. A 3S lipo will really liven up your crawler (just make sure that your ESC can handle 11.1V). Increasing mAh will simply increase the runtime of your crawler.

I run the TP 1350mAh 3S on my Bully (dual motors) and it will fly! The battery will last about 30-40 minutes depending on how much throttle I use...

Sorry but a 7.4 3300mah pack will be able to sustain more amperage than a 7.4 1320 pack. I noticed a pretty good difference on a 55T system as well as my brushless system. 3S vs 2S will be a night/day difference, like adding a 150-200hp shot of nitrous. Going up in Mah might be more like adding an exhaust system.

Originally Posted by honyock

Phillyb,

Which TP are you using? Is it similar in form factor? (<100mm x 50 x 30)

Are you using it with the FXR? I've seen discussions elsewhere here that make me think Tekin's support for 3 cell is mostly informal.

All,

Thanks for the feedback. I'm going through the TP offerings and definitely liking the price differences I've seen. The big sticking point seems to be the amount of "ooomph" I can get in that small of a unit.

There's a 'military grade' TP -- the rc pro lite ms 2000 7.4 2-cell 2s -- that I have my eye on...

I am running tekin RX8 so I wouldn't know anything about FXR. I do know that most ESC's will have issues with 3 cell lipo without a BEC, I believe BEC is required in most cases with 3 cell. 2S runs decent, but I have moved to 3S for extreme wheelspeed.

I tried 2S pack from TP, along with 3S pack from TP, both are same length and width, 3S is taller obviously. I don't have the dimensions with me.

3S
http://www.redrockethobbies.com/Thun...p13203sjpl.htm
2S
http://h1071118.hobbyshopnow.com/pro...d=THP13202SJPL

There are much better packs out. I have been wanting these for quite a while, someone posted them up here I believe.

http://www.helidirect.com/batteries-...c-1_31_923.hdx

[JeremyH]

Originally Posted by phillyb

Sorry but a 7.4 3300mah pack will be able to sustain more amperage than a 7.4 1320 pack.

Well of course....if you increase the amount of continuous and burst current (which comes when you increase the "capacity" of your battery), then you'll get more current from your battery. I assumed that when he mentioned "oomph", he was referring to something that he'd actually be able to notice when he wired up a new pack and pulled the trigger. Personally, it is difficult for me to tell when I switch to a pack with higher burst ratings....but when I switch to higher voltage, I see it immediately.

[phillyb]

Originally Posted by JeremyH

Well of course....if you increase the amount of continuous and burst current (which comes when you increase the "capacity" of your battery), then you'll get more current from your battery. I assumed that when he mentioned "oomph", he was referring to something that he'd actually be able to notice when he wired up a new pack and pulled the trigger. Personally, it is difficult for me to tell when I switch to a pack with higher burst ratings....but when I switch to higher voltage, I see it immediately.

Oh I agree, 3S is the way to go, but I was able to tell a pretty good difference between the 1320 and 3300 pack.

Thing about the 3300 is that its just too big and heavy, no matter what I can't get it placed well. The 3 cell lipo is all the power Ill ever need, but I wouldn't mind a higher C rating, the TP is around 20C. Not to mention the 3300 costs as much as two of the hyperion packs.

[honyock]

Originally Posted by JeremyH

That "oomph" that you're wanting will come from voltage....not mAh. A 3S lipo will really liven up your crawler (just make sure that your ESC can handle 11.1V). Increasing mAh will simply increase the runtime of your crawler.

In the words of Tony Stark, "Is it too much to ask for both?"

I have concerns about the physical size of the 3300, but yeah, the arguments you and PhillyB make about mAh vs V seem sound enough for me.

I need to figure out how/if I can get my wiring diagram in here so I can get a sanity check; especially if I *can* use 11.1V -- since I've got a BEC in there for both the FXRs. (Red wires detached for both to ESC-->Punk connections.

Hmmm...

[honyock]

Originally Posted by honyock

I need to figure out how/if I can get my wiring diagram in here so I can get a sanity check; especially if I *can* use 11.1V -- since I've got a BEC in there for both the FXRs. (Red wires detached for both to ESC-->Punk connections.

Okay, let's try this:



So...

Anything fundamentally wrong here? If not, with the BEC where it is, and with the two red wires from the FXRs heat-shrinked so they don't connect... Am I better off looking at 11.1 V with higher mAh, given I want this beast to 1) run strong, 2) for as long as possible...