Maiden Pursuit 32 : not good. ultra high amp draw. toasted lipos : Running too Wet?

[hsp-sandiego]

I ran my first maiden with a pursuit 32 this morning. de-soldered / cracked banana connectors, smokin, puffed, cracked case 50-100c lipos. Boat was running quite "wet". Please see photo of stinger height. Motor and esc barely warm after 90 seconds. Pretty standard setup for this boat on 4s: leopard 4074 2150kV, seaking 180A, running a Life 1100mAh rX back (yes, with red wire on a adapter wire disabled), prop is sharpened and balanced x445. boat lets in no water through transom, very dry. Hull was modified with a "flooded stuffing tube" setup and hull is carbon reinforced.

Here is the scenario: ran 2s2p 25c and a 30c for maiden and boat seemed to take off nice, although was running fairly "wet." LVC kicked on after 45 seconds and batteries had a slight puff and were warm. Fully charged and balanced of course and I am charging the packs now.. they dropped down to 3.8v per cell and came back to full charge/balanced after 40 minutes at 1c (charging here at home now). I ran my saddle packs from my buggy for a second try and the boat seemed to run great although "wet" and not as fast as i had hoped. de-solder and smoke after 90 seconds with packs blown apart.

flex cable is perfect and is not binding or anything, greased with grim-racer blue stuff.

Question is, would running "wet" draw enough current to do this kind of damage? esc was blinking when after first run. I did set LVC to 3.0v/cell for second run with timer on tX running to see if the LVC was just kicking on early from the first run/maiden.

thank you,
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[PowerDemon]

The C-rating is very low on those packs. Also I would not suggest Turnigy Nano techs because that happens to most people (including myself) who use them. I think your only error was your battery choice.

[srislash]

You say 'banana connectors', do you mean the 4mm type? If so there is a great deal of your problem. But yes, running to wet can totally mess up the amp draw. The stinger should be parallel with hull bottom. Take a ruler and place on the bottom of hull and the length of stinger. Should all run straight if looked at from side.

[tlandauer]

You have batteries that are not up for the task of FE boating! Hard case lipo is not well suited for boat and your C rating is way too low as said.
Get quality lipo and you will see the difference, you are actually lucky that there was no , many did have that running poor quality cells.
Do a search and invest in good lipo batteries, Dinogy or Revo brands are popular with boaters, while you are at it, change to bullet connecters as well, they are a must, I have seen so many failures due to connectors not being able to handle the kind of current an electric boat would draw.
Just running wet should not do this to you although it would increase amp draw.
Just because your ESC is barely warm, DO CHECK VISUALLY that the end of your capacitors are NOT BULGED!!!!
Make sure your COG is correct, if the stinger is set correctly, running a boat with the wrong COG can result in "wet" attitude.

[hsp-sandiego]

the 4mm connectors go into the packs. 6mm Castle Connectors to esc. And I thought racing r/c buggies was expensive! Will re-drill the stinger and drop it down as far as it will go for a even plane with the hull and give it another shot. if no go... classifieds. out of cash for this thing and toasted my race day packs. thanks.

[tlandauer]

That is the problem, these batteries were meant for rc/car/truck. The 4mm banana plugs are not the same as hard wired wires coming out of a quality cell.
I don't think srislash meant that your stinger has to be on the same line as the bottom of your V, he meant it should be parallel, if you drop it down any further, it might encourage "chine-walk"---something you don't want.
Correct me if I am wrong.

[srislash]

That is the problem, these batteries were meant for rc/car/truck. The 4mm banana plugs are not the same as hard wired wires coming out of a quality cell.
I don't think srislash meant that your stinger has to be on the same line as the bottom of your V, he meant it should be parallel, if you drop it down any further, it might encourage "chine-walk"---something you don't want.
Correct me if I am wrong.

You got it Tim. If it is too negative(pointing downward) it will push the nose into the water. Creating amp draw.
Actually the height of the driveline looked good. I just thought it looked a bit negative.

Now 4mm into the packs is certainly the weak point. They are not good for many amps, good for charging and that is about it.

[kfxguy]

Why is it every time I read a thread like this the one thing they all have in common is something called a nano tech?

[revoltrunner]

Why is it every time I read a thread like this the one thing they all have in common is something called a nano tech?

that's not the only thing they have in common

[hsp-sandiego]

that's not the only thing they have in common

? please expand on this.

[hsp-sandiego]

question for tlandauer... would turnigy 40c packs be up to the task? everything is fine on the esc, tested just now. no caps bulging whatsoever; thank you for the tip.

[tlandauer]

question for tlandauer... would turnigy 40c packs be up to the task? everything is fine on the esc, tested just now. no caps bulging whatsoever; thank you for the tip.

I am not familiar with that battery. I used to run 40C Skylipo and never had trouble.http://www.hobbypartz.com/77p-sl5000-4s1p-40c-4444.html
Now I run Grim racer packs:http://www3.towerhobbies.com/cgi-bin...&I=LXAXFT&P=SM. They are costly, I got them when I had a huge discount coupon a year or two ago. I live in So Cal and I find it very convenient for me to pick up Dinogy batteries. These batteries work well for me.
Revo packs have also done well , and threads regarding their performance can be found and you should read a little.
These "soft pack" batteries are good for boats and use no less than 40C rating. many people would say use no less than 60C, in any case, look at the constant rate, not the burst rating as some manufacturers over inflate their ratings.
For 2s I have used Sky Lipo as well as Gens Ace, http://www.hobbypartz.com/98p-30c-5300-2s1p.html .
I have only used 30C rating but they are used with P-Spec set up on hydro boats.
Also, it seems Turnigy Zippy ( blue) fair better. I have two pairs of 2s that I use for my hydro boats and they do well, no puffing and balance well at the chargers.
As said before, read a bit and form an opinion yourself, there are good lipos out there and you have to pay a bit for quality but Dinogy and Revo brands are not that expensive, Hyperion cells are more costly, and they have a good reputation. ThunderPower is another brand which costs a bit more but above those "economic" packs.
It is very hard to recommend a good pack without inviting alot of other valuable opinions and input. Different users with different back ground and usages will tell you contradicting opinions-----but one thing they all agree: cells that work on rc cars/trucks/buggies do not work well most of the time on boats. These hard shell packs somehow don't fair well. Rather the soft packs with a decent rating work well.

[iridebikes247]

Depends on what you're willing to spend I agree with srislash about the bullet connectors and everything causing your situation. Anyway I don't really think there is a perfect pack after trying many. Ran Gens Ace lipos for a long time and love them, then zippy, and also dinogy.

Gens ace were great imo a little bit better than the zippy. I ran zippy 40c packs for a long time pulling 300+ amps, long runs, etc. They held up awesome in the short run. The zippy packs will hold up to high discharge great in the beginning time will tell how much punch they have after multiple cycles.

As for Dinogy, eh. For the money I would just get the zippy 45c. Not impressed with Dinogy at all.


A few fast guys on here are running the Revolectrix packs and have posted fantastic results, speed increases, low temps, etc.

[olwarbirds]

Not to start a big debate or battle here !...I been running the higher c rated nanotechs for over 2 yrs now (same packs) so has my buddy Sean. We run several times a week with high kv setups "SAW" etc...we have yet to destroy a nanotech, but have destroyed numerous other brands. To put what we do in perspective, we run nothing smaller than 10ga wire most the time 8ga, 8mm bullets on esc to motor, 8.5 mm lipo to esc. In any series setup I never use a lipo smaller than 6600mah 40c and up. Maybe we been lucky so far, but I dont think so. I thinks its all got to do with proper setup etc....the problem here is not the brand of lipo its the hardcase small plug into it created a bottleneck (impedance to case/connector) also the wires on these style lipos is too small. I have a bunch of these I use for there intended purpose (offroad sct racing) venom hardcase the same too...

what mah lipos ? if say 5000mah at 25c thats 2.5 x 50 = 125 amps. Your setup and definately if its running wet, was probably pulling in excess of 200 amps Your actually lucky you didnt burn anything else up. Now your 50-100c hardpacks, the c rating is good but most of those hardcase packs use 12-14ga wire and like mentioned small bullets. The Lipos had the amps but it all got bottlenecked.

I know that I've repeated whats been said but just wanted to get you a bit deeper look at why it happened..If you dont know already, those lipos should not be just thrown in trash. You need to make up a solution of saline water and soak them overnight. We all have our own opinions and favorite brands, but for some spending 75-100$ per lipo is not feasible. I know if thats what I had too do, then I would not have the 20 some boats, plus offroad/onroad vehicles and planes that I do...all the best and Happy boating and holidays Y'all.... DJ

[hsp-sandiego]

Perfect... thank you all for the tips on the packs. *makes sense about the hard-packs as well. I used hard packs in the UL-1 I had with over 50 runs easy and no issues, although much smaller boat not pulling near the amps of the Pursuit. Time to look at some packs and order up more Castle connectors. I am familiar with lipo disposal... Radio Shack actually takes them and will properly dispose of them, although the saline water soak is almost easier.. thanks for that tip. My little JAE mini-rigger took a dunk and puffed up a turnigy to the point of disposal. Cool little rigger and really fun to run; hatch came off and all went to hell.
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