HimotoGenesis

Hi guys,

hoping you might be able help? I recently bought a Himoto Genesis RTR and I seem to be going through ESC's lately? Im new to RC boats but have other RC's. If theres anything Im missing, please let me know.

Everything was going fine until I bought a new LiPo as I wanted to extend the running time (10 minutes was way too short for me). Basically - The initial set up was working fine for months and the only LiPo that I was using was a Turnigy (Nano-tech) 4s / 4500mAh / 35-70C

Boat was running standard internals:
125A ESC
2075Kv motor (not sure of brand) Water cooled
6Kg Himoto Servo
Himoto Rx and Tx

In the hope of extending my running time, I purchased a Zippy 4s / 30-40C "8000 mAh" (High discharge LiPo) and this is where the issues began. I ran it for the first time fine. New Batt lasted about 20 - 25 min. Brought it in after 10 Min to cool down and check temperatures, then sent it back out for the remaining 10 / 15min. Battery and ESC's get warm to touch but not burning hot.

Once Batt cut off, placed the original Turnigy back in and it ran for about 3 min then died. (Had to go for a swim)

Servo works, but no throttle. Again, not burning hot?

Brought it home and tested both the ESC and motor with another RC and narrowed it down to the ESC. Motor would throttle with a different ESC but boat ESC would not power any other motor.

Went out and bought a Swordfish Pro - 120 A - S BEC - as the guy at the hobby shop seemed to think the original, even though mentioned 125A, would be luckily to be a 60A (because it was a cheaper ESC) and mentioned that the Swordfish was a guaranteed 120A with 150A peak.

I found somewhere that the 2075kv motor would be about 100A so presumed that 120A was to be sufficient? not sure if this is correct.

I replaced and programmed up, took it out for the first time and it lasted about 15min with the 800mAh - and now - No throttle again, but servo movement.

Does anyone know if its the 8000mAh that is killing the ESC's or if there is something else that I may be missing? Is it in fact the ESC's failing as they dont seem to be burning hot? Well under 100 degrees Celsius.

Is there a simple fix to the no throttle that Im missing?

Thanks guys and appreciate any help

flyinwalenda

My Feedback: (5)

Hi,
First you should read this on LiPo batteries
http://www.rcuniverse.com/forum/rc-c...batteries.html

The mah rating of a LiPo pack is not the cause of the ESC's burning up.
Have you checked the water line used to cool the motor and ESC and make sure it is intact, connected, not blocked, and carrying water?
Does the boat have the stock prop on it?
Are the plug/connectors for the LiPo/ESC in good shape ?

At the moment,when connecting the LiPo do you hear the system arming tones through the motor?
If the water cooling is working then my guess is that it is over propped, the motor is failing, or you could have a faulty connection .
Your best bet is to invest in or borrow a Watt Meter ,connect it between the ESC and LiPo and see exactly what is going on.

wholehog

My Feedback: (1)

I agree with Brian, seems like a wiring issue or an over prop problem. Run a smaller prop on a bigger KV motor, put you some good 5.5mm connectors on your ESC, batteries and motor. Get you a new version Hyperion EOS Sentry Battery Checker to keep up with what you batteries are doing, without one you don't have a clew if you are bringing them down too low or what the charge percentage is when you get ready to shelf them for awhile. If you want them to last or not damage them, by all means get you one of these. It could be you have a flaky ESC or your program isn't correct. I have had very good success with Seaking brands and their programer. Hope this helps some.

HimotoGenesis

Thanks guys,

Hi flyinwalenda

Good read on the Lipo thread, so I can eliminate the mAh. How long do you guys run your boats for per run? Everywhere seems to be about 10 min per batt. Im trying to at least get about 30 - 40min through however many batteries

- Water cooling is free and working and I always run the boat past me to check the water outlets
- Prop - Im running the standard 2 Blade Nylon and the standard Flex Shaft. Have only re-greased everything
- Plug connectors are brand new Gold 4mm Bullets that I changed so I could easily mix match and test across my RC's
- No engine sound anymore. When ESC was working, normal beeps and start up tune were coming from motor. I did notice that loudness changed randomly. When I initially plugged the ESC in, it was loud beeps, but randomly would be real quiet then loud again?

Thanks Wholehog, Ill get some 5.5mm connectors and I do have a batt checker and all batts at full charge are about 4.2v per Cell. Cut offs all occur at the 3.3v - Maybe its the programming. Ive just been putting the options to (default) as per manuals

I have attached some pics if this helps?

flyinwalenda

My Feedback: (5)

Have you been running this to LiPo cut-off every time? Did the motor start to sputter or did the boat cease forward motion and you had to retrieve it?
What brand,model charger are you using? If it has a display, what have the voltage readings been on the pack and on each cell when you started a charge after running ?

HimotoGenesis

Hi Brian,

Both times, yes engine sputtered out, then as I tried to bring it to shore, boat died and ceased to move forward. Unplugging the battery then plugging back in - No music tones from the engine.

Charger is just a 680AC Balance charger - no brand - 4 button - up to 6A charge. I only ever charge at 1c and both my battery tester and chargers generally show about 3.3 / 3.4v when I charge them and after runs. I have run Low voltage alarms set at 3.3v as well

Batteries are only a few months old and the 8000mAh is only a few weeks old. I store the batts at 3.8v and full charge to 4.2v only

If I change the 4mm Bullet terminals to 5.5mm and get a 180 - 200A ESC, do you think this would eliminate the issues? Im happy with the speed that the 4s Lipo's produce.

Can you see any issues with the prop and its height at all?

flyinwalenda

My Feedback: (5)

All I can say at this point is that some condition or component is causing the esc's to fail. Either too much heat or too may amps. You can get a higher rated esc and install it but I would either buy or borrow a watt meter and test the set-up before running a battery through it again. It could be the connections, the prop, or it could be a failing motor. You really need to see how may amps,volts, watts, etc... the set-up is drawing at no-load and under-load Otherwise it is just a guessing game.
Also , I''m not a fan of running a Lixx battery down to LVC . The LVC is there as a safety but I bring my boat, planes, helis, in when the packs are at 3.5v/cell by calculating and setting the timer on the transmitter. In my opinion when a pack is constantly run down to 3.3v/cell under load it is slowly damaging it and that is how they eventually puff and fail. I have packs that are 5+ years old and still have good internal resistance and put out close to their C rating while I've had in the past packs that were run to LVC and in a short period had high resistance ,puffed, and had to be disposed.

HimotoGenesis

Thanks heaps Brian. I might head down to the hobby shop today who sold me the Swordfish ESC and see if he can test the set up. Not too keen on just buying things for the sake of buying them

Thanks again for all or your advise and have definitely learnt quite a bit. Ill let you know how I go

flyinwalenda

My Feedback: (5)

That sounds like a good idea.Hopefully it's a shop with owners/folks who will help you and not just sell you stuff and/or ignore you. Good luck.

wholehog

My Feedback: (1)

You ask about running time, I get to run full throttle, better than off an on the throttle, on all my boats for about six to eight min's. I don't count on the cut off, I have just run clock times and check the batteries for their voltage against the time. Suckie thing about electric, run time compared to nitro is terrible. I can say the best battery on the market is a Giant Power from Mojo Racing, know the guy and have proved out his product. The deal with the better heaver connectors is to keep from having a d-soilder issue with the tremendous heat on the wires. If you do have to get a new ESC, Aquacraft's are good, myself I like the Sea Kings (FalconSekido.com) and there program cards for the price. Don't buy them from China, if you have issues, you will have an issue! The card is simple and it has a default. One other thing Brian didn't mention was your timing setting. I like to run 11.5 degrees, lower and I have a wire heating issue on my setups. If you plan on more boats or more batteries, get you a Hitec x4 charger and a high voltage AC-DC inverter, good place for that is Slot Wing Hobbies. Lets you charge four batteries at a time and different styles at a time, plus the inverter will let you charge at home and use power at the lake if is available. Store your batteries at about 35 to 40 percent charge, never run them below 20 percent and if it is cold outside, always warm them up in the car before using them. This electric thing is expensive up front, but it's a lot easier if you have never been into nitro. Oh, get you a good metal balanced prop, Chris's Hobbies is a good avenue for them at dasboata.com. One last thing, put you some cable ties on your water lines, I have seen them blow off and they cooked the boat. Hope these things have helped and if you have more questions, just ask. Good boating!