Best lipo for stock esc ?

[RiverRat]

What is the best lipo we can get away with running the stock esc?

[RiverRat]

Thanks for the help. Dont worry, Ill keep it a secret after I burn a few esc's. Think ill start with something that has a 50c rating.

[Jeff Wohlt]

You do not need the xpense of a 50c. 25-30 is plenty as long as you stay in the 4500-5000 and up mah.

If you build boats that want 120 amps constant then buy the cells for that. For fun and sport it is doubtful you will ever need 130 amp constant. I figure anything that can handle 100 amp constant will do for me. Sure oyu may spike up to 120-130 once in a while but those cells will handle it.

Some say just buy the best and cry once but there is a BIG difference in those cells from a price perspective. I guess it is what your wallet will handle.

[RiverRat]

Is the only thing that burns a esc the volts? Or can you also burn a esc with to much c rating?

[rob1699]

I started off with 2 x 6000mah max amp lipos in my SV until one of the packs puffed in a big way after only about 15 cycles..doh..!

Now I took the excellent advice of this board (see post on Puffed Maxamp lipo a few weeks ago) and went with a pair of 25c Poly RC 5100Xp 2S and what a couple of little beauties they are. The top speed of the boat with the max amps (gps) was 39.4mph, and with the Poly Rc's I can now get 42.6mph with no other changes to the boat...they also seem to have so much more punch too. Oh, and this is all with the stock motor and ESC, and X642 prop. I got mine from RC lipos, and Pat is a wealth of helpful advice (and he worked out a great price for me for 4 packs too).

Hope this helps.

Rob

[RiverRat]

Thanks guys,
Yes I did read your max amp post, but as expected the hydro120 came up.
The confusing thing to me is the amps. The packs you got have many more amps then the esc from what Im reading. If you got that kind of jump just changing brands then Im in.

[rob1699]

You know I still haven't gotten round to installing my Ammo 2300 and Hydra 120 yet - just having too much fun with the stock motor/esc...praps I'll wait until I fry something first maybe..

I'm totally blown away by the increase in performance of the Poly RC's.

Rob

[deestingray]

Just to clarify something River Rat, buying a big mean high C lipo won't cause a blown ESC, they are merely there to provide the power. The lower the C rating, the less power they can provide, hence one of the reasons that you will get a puffed pack, usually because one might be literally running it completely dry and lipos don't like that.
A good start for an SV27 for instance is something that can provide that power.

Lets start with the fact that an SV27 esc is rated at 45 amps. At very minimum you want a lipo that can deliver at least that much power. So lets say you had a 4500mah 4S lipo, you wouldn't want anything less than a 10C rating.
The way you work out how much power a lipo can deliver safely is multiply the mah rating by the C rating. In this case you have a 4500 milliamphour battery which equates to 4.5 amp hours. Another way of defining this is that if you theoretically had a motor that used 4.5 amps constant, it would theoretically take 1 hour to drain the pack to zero, that is the way that I remember anyway.....
So then you take that 4.5 amp hour rating and multiply it by 10C which gives you 45amps.

Now, in FE boats the power demand is often high due to a number of different things. A high C lipo will not blow an esc. High volts will only blow an esc if that esc isn't rated to take that much voltage. Esc's will blow for a number of different reasons, it is often the users fault by overpropping or running for too long without checking temperatures.

With Lipos, it is a good practice to be careful when using them, my motto is that if you abuse them badly, they will abuse you so based on what I have just explained, you wouldn't buy a 4S4500 10C lipo for your craft.

A good rule of thumb is buy a lipo that is capable of at least 1/3 more power output than what you demand from it. In the case of a 4500mah battery, something around 25C is what you want. The higher you go in C, the better the battery can handle the power draw but the more expensive it is. Just because a battery can deliver a million amps(overkill totally unrealistic), doesn't mean that your motor is going to use that much. Battery's don't push power into esc's, motors draw power through them. Motors are like a big vaccuum machine, the harder they work, the more they suck. I hope my ramblings have cleared something up for you.

[RiverRat]

Your ramblings are good, makes perfect sense to me now. Thanks

[SweetAccord]

Not ramblings, this is factual. Good job in explaining that clearly and throughly!

[ibyte]

Just a quick question is a 20c 5000 lipo okay for the boat? man i spent alot of money on reedy and losi 2 cell 5000 20c packs and just want to know.thanks guys

[SweetAccord]

Higher the better, but 20C should be fine, but would not go below that.

[ibyte]

Higher the better, but 20C should be fine, but would not go below that.

thanks i wont go lower than 20c

[Jetbill]

Looking out for a future upgrade in motor and esc, any suggestions on this battery selection?

Enerland 5100 25C
http://www.rclipos.com/PQ-5100RXP-2S.htm

Enerland 5000 30C
http://www.rclipos.com/PQ-5000RXQ-2S.htm

Flightpower 4500 30C

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRWE2&P=7

Trakpower 4900 25C

http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXRWF7&P=7

Thanks for any hellp..

[ice329]

I have a set of PQ 7.4v 5350's there like 16c/20c I have heard that the packs are actually a high c but even at 16c still plenty for the SV. I like the packs, I use them in my Traxxas Truck to and they last like a half hour, in the boat I cut the run at about 8 or 9 miniutes just to be safe since the ESC's cutout is not ment for lipo. Like them a lot in the truck but for the SV I still like the IB cells, they pour power out and the boat is more stable to me.