Batteries, Wires and Connectors Extremely Hot!!!

[barmonkey]

I had my first chance to run the Stiletto today after spending the last few days reading most of the posts here. Without any info on C/G or where to set the outdrive, I settled for placing 2 5000mAh 2S one in front of the other and setting the outdrive all the way up and neutral. The only mods I made were to enlarge the hole on the motor cover, made a lexan battery box lid, replaced the imitation S215 for a real Prather S215, and replaced that large prop nut with a more appropriately sized prop nut.

I also set the ESC with the following parameters: Battery: LiPo, Cut Off: Low, Cut Off Type:Idle, Brake: Off, Timing: Low, and Throttle Curve: Linear

Anyway, The wires, connectors and batteries are getting extremely hot. I was prepared for the Deans plugs to be hot, but the wires and batteries were extremely hot also. My batteries actually have 5.5mm bullets and 8 gauge wires, but I have some 5.5 bullet to Deans adapters that I made which have served me well for other set-ups.

The ESC seems to be OK and unfortunately I don't know how hot the motor was because this dummy left the dummy motor cover in place and forgot to bring my screwdriver to the lake so I could remove it. but the wires and connectors leading to it seemed to be cool.

All of my battery packs were Flightmax 5000mAh 2S. The first packs were only 20C and pretty well at the end of their life span, but I planned to only use them for the initial run with what little they had left in them. The second packs were 30C (actually 5800mAh) and they performed well, but the connectors got so hot they melted the factory Stiletto battery cover The third packs were 40C and things were as hot as with the 30C packs...fortunately not hot enough to melt Lexan!

So given the above information, does anyone have any thoughts or suggestions?

Thanks in advance for any help

[Fluid]

There are several possible causes of the excess heat. It is impossible to diagnose the problem definitively from afar.

- Running down to LCV. How long did you run the boat? In hot summer temperatures, running all the way to a "low" LVC will really warm up the motor, ESC and packs.

- Inadequate cells. The 20C cells, particularly cheap FlightMax cells, are definitely not enough for the boat. ProBoat specifies 25C minimum. Even the "40C" packs may not be enough as FightMax is known to exaggerate their specs.

- Timing not optimum. The 1800 motor likes some timing, not enough can cause excess heat. Try Medium timing and see if that helps. If not, go back to low.

- Boat trim may be too wet. Running any boat wet, or with too much of the hull in contact with the water, increases amp draw significantly. That means more heat in everything.

- Binding in the driveline. The Stiletto I reviewed had almost no lube on the flex cable from the factory, and without lube the friction goes through the roof - high amp draw, high heat.

- Too much prop. The P215 may be too large for the packs you have or the way the boat is trimmed. If the prop is running too deep that increases the load and adds amps. I assume it is sharpened and balanced.

Getting a tunnel to run well can require some time spent trimming the boat. There is plenty of info on CG and motor settings available, and the Owner's Manual has some good tips.



.

[sleep4now]

I had my first chance to run the Stiletto today after spending the last few days reading most of the posts here. Without any info on C/G or where to set the outdrive, I settled for placing 2 5000mAh 2S one in front of the other and setting the outdrive all the way up and neutral. The only mods I made were to enlarge the hole on the motor cover, made a lexan battery box lid, replaced the imitation S215 for a real Prather S215, and replaced that large prop nut with a more appropriately sized prop nut.

I also set the ESC with the following parameters: Battery: LiPo, Cut Off: Low, Cut Off Type:Idle, Brake: Off, Timing: Low, and Throttle Curve: Linear

Anyway, The wires, connectors and batteries are getting extremely hot. I was prepared for the Deans plugs to be hot, but the wires and batteries were extremely hot also. My batteries actually have 5.5mm bullets and 8 gauge wires, but I have some 5.5 bullet to Deans adapters that I made which have served me well for other set-ups.

The ESC seems to be OK and unfortunately I don't know how hot the motor was because this dummy left the dummy motor cover in place and forgot to bring my screwdriver to the lake so I could remove it. but the wires and connectors leading to it seemed to be cool.

All of my battery packs were Flightmax 5000mAh 2S. The first packs were only 20C and pretty well at the end of their life span, but I planned to only use them for the initial run with what little they had left in them. The second packs were 30C (actually 5800mAh) and they performed well, but the connectors got so hot they melted the factory Stiletto battery cover The third packs were 40C and things were as hot as with the 30C packs...fortunately not hot enough to melt Lexan!

So given the above information, does anyone have any thoughts or suggestions?

Thanks in advance for any help

I've recently ran into this issue too somewhat , not getting the heat your getting but the main cause was my batts. 20c I'm surprised you didn't pop them.. I started with cheap lipos to , can't member what brand , (ebay) then after melting the outer sheath on the connectors , I talked to my local hobby shop and they said they reccomend with Boats to at least run lipos with 35c and quality packs, because they always have a hefty load drawing lots of amps. I picked up some thunderpacks 45c and WOW what a difference! No heat issues, anymore. I would start with that. I never changed anything on the ESC other then Lipo. Hope this helps a little....

[Racer944]

FWIW, I woudl not be too quick to blame the packs. I am running new, good quality Gens Ace 5000 mah 40C packs, and am also experiencing the same issue both with the stock prop and an aftermarket prop. Boat is running very well and seems trimmed very well, but the heat at the ESC/battery connectors is very high. Also ran it with an Octura X642 prop (ran well by the way) and the factory deans connectors on the ESC became unsoldered...

Eric

[barmonkey]

For the record, I never expected the 20C packs to do the job...just wanted to use what little life they had left for the initial adjustments. I was also working on the assumption that the S215 was a safe starter prop.

I had a chance to check out the outdrive...I found that the prop was very hard to turn. I did pull the cable out and lube it before I ran it...after installation it didn't seem that difficult to spin. I removed the cable to inspect it and found no defects. I then replaced the cable and it spun with just a bit of resistance (in all cases this is with the motor removed). The cable and teflon tubing must be binding at some point creating a lot of drag...This may be the biggest issue.

Darin Jordan's modification may be the necessary fix. I did attempt to take the case apart but was trumped by a factory stripped out hex bolt.

Another option was to use my O.S. lower with the Hyper Performance motor adapter...it turns out that it is about 1/4 inch too short! Hasn't been a good day for the repair department.

[Racer944]

FWIW, I have done Darins mods to my outdrive (not the oiler), and its quite smooth, but as you can read above, its still hot on the connectors/batts.

Eric

[jamespl]

I find that my turnigy 5800mah 25c packs run cooler than my 5000mah 40c turnigy packs. Also the boat seems a little faster on the 5800mah packs! When I got the boat the first thing I did was grease the shaft (which I do after 2 runs) and replaced the deans for ec5 connectors, the packs get quite warn but the ecs is always cool.

[barmonkey]

I managed to extract that factory stripped out screw (the one by the cavitation plate) and finally got the outboard apart. That Teflon tube fits pretty tight, which is certainly causing some excess friction. I decided to go ahead and do the brass tube mod using 1/4 O.D. K&S tube. I was thinking that others used 7/32 but the 1/4 fits OK. The drive cable seems to be much happier with the reduced friction. Probably because the cable is only rubbing in one or two spots rather than the entire length of the cable. The oiler looks like a good idea, so that may be attempted in the near future.

For the next runs I will definitely set the ESC to "Slow Down" instead of "idle" and for now the cut off will be set to "High" Not sure if I should change the timing...there is no medium...just Low or High. The runs will be very short to check the temps!

[Racer944]

Anything to report back? Are temps better? I am still trying to figure out my issue with heat at the wires/connectors from the ESC...

Eric

[barmonkey]

Unfortunately I am waiting for a new flex shaft to arrive. I was trying to see if it would loosen up any in the stock Teflon tube by running it with a drill and one of the cable strands broke and balled up outside the tube. Glad this happened while experimenting rather than while I was running it!

I did manage to install my Wattmeter for a partial run though. It showed a PEAK of over 80 Watts. This is only a peak, so I don't know how long or what the sustained Amp draw was. Once I get my new shafts I plan to use my Eagle Tree Data Logger to get some better data. I also checked the temps after that short run, and batteries were around 106 degrees...but like I said this was a short run.

As others have suggested, changing the battery and ESC connectors to a larger 5.5mm bullet connector will help. But the batteries are still going to get hot regardless. I think the only answer is going to use a smaller prop and better batteries...but using a smaller prop just isn't much fun now...is it?

[Racer944]

Smaller prop? Are you not running pretty much a stock prop?

Eric

[barmonkey]

Yes, I am using a Prather S215 which the stock prop is supposedly a copy of (looks really close to me). It is a 40.6mm prop with a 1.6" pitch...I was thinking that it was 42mm. So the option is to either reduce the diameter by .6mm (which is beyond my expertise) or use an Octura X640 which has the same pitch but a smaller diameter. Since I don't have any X6 series props yet, I'll have to try an Octura X440 or M440, which are 1.4" pitch props. This will yield a slower speed, however the Amp draw should drop thus reducing the strain on the batteries and the temperature as well.

ON a sad note, my new flex shafts did not arrive in the mail today so my Stiletto is stuck in dry dock for now...