Bear with me if I waffle a bit.
I was very happy with the Graupner Ti Amo I bought in February. Fast enough for what I wanted but I would have liked a little more run time. The shop had sold me a pair of 9.6v 3800Mah sticks together with the Planet 5 and ESC all of which they fitted before collecting the boat. I started a thread under the batteries section and it seemed 5000Mah were available, but the Overlanders I first looked at were a bit pricey so opted for the recommended Component Shop ones. Initially everything seemed ok ish but the more I used them (the boat gets used usually 2 or 3 times a week) the more I noticed they seemed unable to hold high discharge rates for very long and it became more noticeable the more I used them. In fact the performance dropped off noticeably after only a couple of minutes and to get back to something like full power I had to "rest" them for a while before going back on the throttle. Even then the performance dropped off really quickly. I put this down to cheap batteries and bought a pair of 9.6v 5000Mah from Overlander.
Newly delivered and fully charged off I went. Same problem. The boat went like the proverbial whatsit off a shovel for a couple of minutes then the power started to drop off. I persevered, resting the batteries periodically but still the power drop off was there. More interestingly towards the end of the run time when I applied small amounts of throttle to bring the boat back in, the engine would stop/start like someone was switching it off and on. This had also happened the last time I used the boat with the Component Shop batteries.
So, when new the boat would quite happily run at close to full power for most of the run time followed by a quick but manageable decline in power at the end, now power loss begins almost immediately you start to use it, and it's seems to be getting worse, and it doesn't seem to matter which batteries I use the problem is still there.
And so, where does the problem lie? Batteries - originally I thought yes but now I don't think so. Planet 5 - I don't think that has anything to do with the problem. That leaves the ESC and motor. I know nothing about ESCs and don't understand how they work (I'm still very much a novice when it comes to RC).
One small issue I have with Graupner is that the motor pre-fitted is a Speed 600. That's all they tell you. Nothing in the paperwork supplied with the boat tells you which variant it is. Even the motor itself carries absolutely no markings or labels whatsoever. What I did notice yesterday (and I hadn't checked previously) is that after the first outing, with all its stops and starts, the motor was seriously hot. Touching it was not a good idea. So was the shop wrong in supplying 9.6v batteries? Am I slowly cooking the motor and that's what's causing the problem? The only possible clue I have with this is that for the first time yesterday I noticed on Graupner's web site under accessories for the Ti Amo that they list 8.4v batteries. Would 9.6v do this over a long period of time with many runs?
Or, being the novice that I am, am I missing something else?
Any help or suggestions very much appreciated.