Setups

[NitroVal]

I guess I'll do the honor of asking if anyone has tried different settings on the boat, and whether they work or not..
Post what ya got, and GPS speeds if ya got em..

[Chris Nicastro]

Stock 36mm props, stock motors, stock ESC's, drive angle 0deg, 4S 3200 Venom Lipos packs = max speed before props fail 48mph on Garmin GPS

[OldSoldier99]

I'm working on the following setup... suggestions/warnings requested:

First, I'm new to the forums and don't have much experience with boats (I'm a monster truck guy). Here's what I've done to my EKOS so far:

1. Converted to Traxxas high-current connectors for compatibility with my other vehicles and batteries.

2. Connected the two battery inputs to each other. The idea was to make sure each ESC had access to the same amount of power ( in case the batteries were not perfectly matched or evenly charged).

3. Installed a series battery adapter to allow me to run two 2s cell batteries as a 4s battery.

I found that everything works well and the boat is wicked fast for about 5 seconds. I realized my Lipos are not rated for 60 + 60=120amps continuous... they are only good for about 100amps. So as I see it, I have two choices...either I get higher rated 2s batteries or buy some expen$ive 4$ batteries. What do you guys think?

OldSoldier
EKOS and Brushless Pro Boat PT-109

[Fluid]

1. Coverted to Traxxas high-current connectors for compatibility with my other vehicles and batteries.

Not a great idea. Those connectors are high resistance for a boat - boats are not trucks and they draw far more current. The best solution is to use 5.5 mm gold connectors. Reducing the plug resistance will mean less heat and more power going to the motors.

2. Connected the two battery inputs to each other. The idea was to make sure each ESC had access to the same amount of power ( in case the batteries were not perfectly matched or evenly charged).

If this means adding more wire - bad idea if I understand what you did and not necessary. The goal is to use the minimum length of wire everywhere to reduce resistance. Excessive wire length will cook your ESCs. The two motors will never be perfectly matched in rpm no matter what you do.

3. Installed a series battery adapter to allow me to run two 2s cell batteries as a 4s battery.

Adapters can be good, but they need to have the minimum length of wire practical. If you use the 5.5 plugs you won't need those high-resistance "adapters".

I found that everything works well and the boat is wicked fast for about 5 seconds. I realized my Lipos are not rated for 60 + 60=120amps continuous... they are only good for about 100amps. So as I see it, I have two choices...either I get higher rated 2C batteries or buy some expen$ive 4$ batteries. What do you guys think?

What happens after 5 seconds? Does it stop? Does it burst into flames? What cells are you using? Why do you think that you are using 120 amps? We can't give meaningful help without more detailed information....

.

[OldSoldier99]

Fluid,
Thanks for your reples. Two things:

1) I thought the new Traxxas High-Current connectors were created specifically for high power/low resistance brushless applications like this. They are supposed to be as good or better than Deans Ultra connectors. Brushless ESCs for monster trucks are routinely rated at over 100 amps. I'm not talking about the old Tamiya-style connectors that most RC cars and trucks use.

2)

I found that everything works well and the boat is wicked fast for about 5 seconds. I realized my Lipos are not rated for 60 + 60=120amps continuous... they are only good for about 100amps. So as I see it, I have two choices...either I get higher rated 2C batteries or buy some expen$ive 4$ batteries. What do you guys think?

What happens after 5 seconds? Does it stop? Does it burst into flames? What cells are you using? Why do you think that you are using 120 amps? We can't give meaningful help without more detailed information....

After about 5 seconds of wicked fast running, the boat slows down to about 2s speed. No matter how far you pull the trigger on the transmitter, it wont go any faster than about 2s speed. I assumed my batteries were not capable of providing any more current. I got the 120 amp figure from the fact that there are two 60amp ESCs in the EKOS. Since I have the batteries in series, I assume they would have to be capable of 60+60=120amps at full throttle. My cells are Zippy Lipo 30C, 2s, 5000. I think the 30C rating is the burst rating and I think the continous rating is 20C. 20C x 5000=100amps battery capacity.

[Chris Nicastro]

What your seeing is the ESC's demanding a lot of power and your packs are delivering the best of the top of the charge which you could call the Burst Current. Then the pack settles in for the remainder of the run and just provides its usual discharge power.
When you get the chance you should get a couple of 3S 5400, or anything over 4000mah, packs. That will give you better runtime and higher speeds. You could go to 4S 3200-3600mah packs that will just squeeze into the hull/hatch w/o any mods.

[Fluid]

1) I thought the new Traxxas High-Current connectors were created specifically for high power/low resistance brushless applications like this. They are supposed to be as good or better than Deans Ultra connectors. Brushless ESCs for monster trucks are routinely rated at over 100 amps. I'm not talking about the old Tamiya-style connectors that most RC cars and trucks use.

It doesn't matter what trucks are "rated" to pull, boats pull a higher continuous amperage. There have been hundreds of car and truck guys who thought like this before they found out the facts the hard way. I'm just trying to save you from a train wreck.

Deans connectors are only good for about 60 amps. Replace the cheezy car plugs with high-quality 5.5 mm gold connectors which are good for well over 100 amps continuous.

2) After about 5 seconds of wicked fast running, the boat slows down to about 2s speed. No matter how far you pull the trigger on the transmitter, it wont go any faster than about 2s speed. I assumed my batteries were not capable of providing any more current.

Perhaps, but to lose half the voltage is not just burning off the top of the charge - it means the packs you have are junk. This is strange because the Zippy packs I've seen are better than this. The lousy connectors could be part of the problem, or it could be the bridge you have between the packs. Set the boat back up the way it came from the factory.

I got the 120 amp figure from the fact that there are two 60amp ESCs in the EKOS. Since I have the batteries in series, I assume they would have to be capable of 60+60=120amps at full throttle....

The motors will pull the amps demanded of them from the props and hull - it is usually well under the ESC's rating in RTRs. You can prop up and pull 100+ amps per motor. Poorly aligned drivelines and a wet running boat can do the same thing. These are not Hacker or Neu racing motors, they won't pull huge amps unless something is wrong.

If your packs are okay, then the problem is likely something you have done to modify the boat's electrics. Put them back the way they came and try again to see if you still have the same problems. Otherwise it may be something wrong with the ESCs. Problems like this are difficult to diagnose by remote control....



.

[Chris Nicastro]

OH! you made a 4S pack from 2 X 2S packs to run both motors? I missed that if thats that case then you just dont have enough battery to do that from 5000mah total. For the power demands this boat has you need 2 X 4S packs (or whatever you want to run) or your going to damage your packs from over stressing them and temps. If you run it with the individual packs your total capacity is over 10,000mah. Your just quick discharging a smaller pack thats why your not seeing the run time but you are seeing the performance potential.

The ESC's are rated for 60A and you cant go wrong with the EC3 plug or Deans Ultra or the Traxxas plug. If you upgrade to higher power equipment then change the plugs to high current bullets or something you like better.

[Brushless55]

After about 5 seconds of wicked fast running, the boat slows down to about 2s speed. No matter how far you pull the trigger on the transmitter, it wont go any faster than about 2s speed. I assumed my batteries were not capable of providing any more current. I got the 120 amp figure from the fact that there are two 60amp ESCs in the EKOS. Since I have the batteries in series, I assume they would have to be capable of 60+60=120amps at full throttle. My cells are Zippy Lipo 30C, 2s, 5000. I think the 30C rating is the burst rating and I think the continous rating is 20C. 20C x 5000=100amps battery capacity.

I think those batteries should be 30c cont.. so 150amps cont..
and 40c burst..
Possibly

[OldSoldier99]

Thanks to all for your wisdom. I will make some changes over the weekend and report back. I have ordered some 4S 4000mah batteries, but it will take a few days for them to arrive.

OldSoldier

[OldSoldier99]

Lipo Batteries

I think those batteries should be 30c cont.. so 150amps cont..
and 40c burst..
Possibly

I just looked it up on the Hobby King website. You are correct...the constant rating is 30C and burst is 40C. If the ratings are accurate, that should be enough power to run my unorthodox setup. I'm begining to suspect Fluid is right and my modifications are suspect. I'll make some changes and report back later.

By the way, have you guys already fought the Zippy vs. MaxAmps war on this forum? I've seen that war fought on some of the truck forums.

Thanks again to all.
OldSoldier

[OldSoldier99]

Connectors

Deans connectors are only good for about 60 amps. Replace the cheezy car plugs with high-quality 5.5 mm gold connectors which are good for well over 100 amps continuous.

My Castle Creations Mamba Max Monster ESCs use the 5.5mm gold bullet connectors you speak of. I have a few extras on my work bench. The only down side is they are not keyed for polarity so you are on your own to make sure you don't mess up. I guess at this level of the hobby we should be able to handle that......as long as we're sober

The other issue with the bullet connectors is battery storage. If you lay them down or they fall, there is a great chance of them shorting. I assume you have covers for them and replace the covers as soon as you remove them from the boat.

[OldSoldier99]

Battery size

When you get the chance you should get a couple of 3S 5400, or anything over 4000mah, packs. That will give you better runtime and higher speeds. You could go to 4S 3200-3600mah packs that will just squeeze into the hull/hatch w/o any mods.

I have a Venom 3S 5400 that I use in one of my monster trucks. I was not sure it would fit in this boat. What is the max height in the battery compartment. I've estimated it to be 30mm.

[Fluid]

My Castle Creations Mamba Max Monster ESCs use the 5.5mm gold bullet connectors you speak of. I have a few extras on my work bench. The only down side is they are not keyed for polarity so you are on your own to make sure you don't mess up. I guess at this level of the hobby we should be able to handle that.......

Nope, polarize them yourself. Put the male on the negative wire on the pack and the female on the positive. Don't put males on both pack wires! I have seen too many experienced guys - who run non-polarized 5.5s - plug in the wrong wires and fry their ESC.....



.

[OldSoldier99]

Nope, polarize them yourself. Put the male on the negative wire on the pack and the female on the positive. Don't put males on both pack wires! I have seen too many experienced guys - who run non-polarized 5.5s - plug in the wrong wires and fry their ESC.....
.

Fluid,
That sounds so simple, yet I never would have thought of that! You rock!