Which lipo ?

[Jlov]

I am upgrading the ESC in my boat to a Swordfish 200amp esc. and the motor to a Leopard 4074-2150kv. I currently have a few sets of Turnigy 7.4 2S 45c-90c 5000mah. What will be my advantage in going up to a 3S or 4S lipo? Longer run times? Will it be faster? Also is it difficult to program this ESC? Thx in advance Jeff

[tlandauer]

With a 2150 kv motor, I am assuming you run 4s. No point to run 3s since that will slow down your boat considerablly.
But there are a few points here, one single 4s is superior than running two 2s connected in series. Less internal connectors = less internal resistance.
So using one single 4s/5000 mah is better , but in what boat? if the boat would not take the physical size of a 4s, then you are stuck with using two 2s, such as the UL-1 I have.
I run two 4s connected in parallel ( 4s2p) to double up the capacity, that increases run time and is easier on the batteries, but that is because I have the space in my boat.
To run a single 3s battery you will see a speed decrease, and if you connect two 3s in series, you get 6s voltage( 22.2 v), too high for you 2150kv motor. If you connect them in parallel ( 3s2p) and you still get a slower speed than running 4s.
You will have longer run times only if you double up the capacity, meaning you connect the batteries in parallel. So two 4s/5000mah ( 4s2p) will become 10,000mah, voltage remains the same at 14.8v.

[Jlov]

Yes unfortunately it sounds like I have this same problem then as they are going in my UL-1 also. So based on what you have said I guess im stuck running the 2S lipos I have?

Also I have seen some people doing this cut out in front part of tub on both sides in a UL-1. Would this help in fitting some 4S lipos in UL-1 ?


Coincidentally this pic I found above of this UL-1 with cut out in tub for the lipos is running exact same ESC and motor Im putting in mine. Maybe that's why he made the cut outs so he could try to put in 4S? Ive read some people cut these holes in front of tub on UL-1 and place the batteries sideways and into holes to stop chine walking and make boat ride more stable. I was thinking it might help me fit the 4S lipos in this way. Thx Jeff

[Shovelnoserc]

You could fit 4s but they have to be small ones. like 2500 to 3200ish mah. They tend to be smaller in size.
I once fit a pair of 4100's. They were the ECO Power from Amainhobbies. I removed the cases and used some heat shrink on the cells. The lid was a little lifted on the bow of the boat.

[Jlov]

Yes I want to try and run this setup on 4S so I will do some research on 4S 3200mah dimensions. Thx

[Jlov]

So tlandauer I can safely run (2) 4s2p 3200mah in parallel on this motor and ESC? What C rating should I get? Also can you explain or post a pic of how I will wire in this ESC & motor so the lipos are in parallel and not in series ....Thx for the help everyone.

[tlandauer]

Yes---for your 1st question.
What kind of connectors are on your ESC currently? If you use 5.5mm bullet and male on positive and female on negative (ESC), you will be able to use this adaptor:http://kintecracing.com/Connectors___Adapters.html ---fourth item down the page. The two positives from the (2) batteries goes to the red plug, then you plug that into your ESC's positive terminal. The two negative from the two batteries) go into the black plug, then that goes into your ESC negative terminal.
Get no less than 40C, in my opinion in this boat you will be better off by running good 5000mah 2s lipos connected in series. The reason I say that is to spend the money on 3200 mah only for this boat means when it comes to other boats you will want the higher capacity cells. If I were in your position I would want my 4s lipos be useful on other applications. But that is just my $.02 .
It is your call, but get good lipo batteries.

[tlandauer]

here is a picture:DSCN4954_5202.jpg DSCN4955_5203.jpg
Cheers!

[lenny]

Or you can make you own parallel connectors,
With some 5.5 bullets soldered together like this to.

CS33009.jpgCS33008.jpgCS33032.jpg

[Jlov]

Yes because I have (4) 2s2p 60c 5000mah lipos with 5.5mm bullets. If there is not much to gain by going to 4s then I may just stick with the lipos I have and run them in series like I have been doing with the stock UL-1 ESC and motor. And thanks for that pic it gives me a much better understanding or lipos running in parallel now. I just assumed if I was upgrading motor and ESC I would need to use diff lipos. the lipos I have are Turnigy 4s2p 60C 5000mah. Are those considered "good" lipos? I have a flats boat and three kids which take up most of my free time so unfortunately this is probably only rc boat I will own. So don't mind spending a little dough on it! Thx Jeff

[Jlov]

Thx Lenny those look awesome. But as I found out with recently soldering the 5.5mm bullets on my lipos soldering is NOT my strong suit ....lol

[tlandauer]

Yes because I have (4) 2s2p 60c 5000mah lipos with 5.5mm bullets. If there is not much to gain by going to 4s then I may just stick with the lipos I have and run them in series like I have been doing with the stock UL-1 ESC and motor. And thanks for that pic it gives me a much better understanding or lipos running in parallel now. I just assumed if I was upgrading motor and ESC I would need to use diff lipos. the lipos I have are Turnigy 4s2p 60C 5000mah. Are those considered "good" lipos? I have a flats boat and three kids which take up most of my free time so unfortunately this is probably only rc boat I will own. So don't mind spending a little dough on it! Thx Jeff

I must admit that I am not familiar with these batteries, people use them with different/opposite results as in everything else, lol...
Make sure that they are not hardcase lipos designed for cars, in boat application we prefer soft cells like air/heli cells.
Your 60C rate is good.
Monitor your temp as you run the upgraded ESC and motor, bring her in after a minute or so, gradually increase the run time, but do not run your batteries below 30% reserve. For a 5000mah battery, there should be at lease 1500 mah left in there.
I too made my own plugs like those lenny posted, it works but there is one feature I like about the Kintec plugs---they are angled out, like "Y", this makes the wires on the batteries much happier: with the straight ones you need to contort the wires to fit. So if you do make your own, angle them out like Kintec's.

[Jlov]

The attached pic is the lipos I have. They are soft case. If I am going to use the current sets of 2s lipos I have will I still need to run them in parallel ?

[tlandauer]

No, you connect two of these in series and they will give you 14.8 volts.
Yes, this soft pack will work.

[Jlov]

Ok motor and ESC will be here tommo. In first post of this thread is the ESC that's coming. So the three wires from one side go to motor,how do I connect the other two wires to the battery? I sold the stock motor and ESC so I cant use it as a reference