Hi guys I'm looking for yet more help and advice. My billings white star has a MFA RE 380 7.2 volt motor with a viper 15 amp 6 to 12 volt esc, a 9.6 volt rc car battery. I have just tried the boat in my pool only to find that after 10 feet the motor cuts out. I have checked the motor to see if it's getting hot, it's not, checked the esc for the same and that is cold. I have also checked the battery and that is still charged, I also tried another battery 8.4 volt 3000. Still the same. Your thoughts would be great please. Many Thanks. Steve.
Hi Steve, your comment about the battery seeming flat but showing 7.2volts. it could be that the battery capacity is nil or very low, put a 6 volt bulb across the terminals to act as a load, then monitor the ammeter, if the amps drops very quickly the battery is dead. Hope this helps Mark
Hi Steve What radio gear are you using? If it's not 2.4 is the aerial above the deck? Is the motor suppressed? Are your heavy current wires remote from any receiver and servo wires? Your symptoms sound more like radio interference than battery power problems. The advice given so far should help you solve faulty wiring and batteries. You do need good connections between the battery and ESC and motor. Electrics deteriorate over time and I have found the Tamiya type connectors to be unreliable at high current. I used to squeeze the female socket together and clean the male plug with fine sandpaper. Another common problem with older equipment can be corrosion in any of the black wire connections. I recently repaired a 7.2v NiMh that gave correct voltages but failed under load. The problem was corrosion inside the black wire where it had been repeatably bent when being fitted in a boat. I traced it to a thinning of the wire near the battery. Pulling on the wire resulted in the copper parting where it was rotten. There should be little or no give in good wiring. Replacing the wire restored the battery to full working order. Good hunting and I hope you find a solution. Dave
Hi Dave, Radio is new 2.4 so am I right in thinking that rules out the interference ?
The 8.4 battery that I also tried is also new and the same was happening with that battery plugged in. I think I am going to try a New 7.2 volt 3000 mah battery and see how that goes and if I still have the problem the look at perhaps a new motor which has been in the boat for over 10 yrs and sat still for 90 % of that time.
Yes 2.4 is pretty interference free, but you do need to separate the dirty high current wires from all signal wires. I very old motor may be generating lots of interference and could benefit from some suppression. The ESC is also subject to interference and if this is an old VIPER unit there was a faulty batch sold several years ago but I have had no problems with the several I have used in recent years. I believe you have ruled out battery and plug problems and the finger is pointing to a motor/interference problem. I am assuming you can still control the rudder servo at a greater range with the motor not running? Some modern radios have a low power range test mode which may be causing the short range. Can you try another motor? It could be any motor and not fitted in the boat, if the symptoms disappear you will have found the problem. Good luck Dave
Morning Dave, the rudder servo works fine so that's that one out. I do have another motor that came out of an old rc glider, the motor is a simprop Power-Speed 1500-10 12 volt. I'll try this one later today and post the out come. Thanks for your help Dave Steve.