Batteries get super hot!

[M3Armand]

Is it normal for the batteries to get hot? I'm running the stock 550s with water cooling. It's about 75F outside. While the motors get hot, they are not unbearable to the touch since the Traxxas water cooling works pretty well. But it looks like I've fried several 6 cell NiMh's with the boat last year. I believe I'm running 2 teeth higher pinions (16t) than the standard (14 tooth). But I didn't think this should have made much of a difference regarding the heat of the batteries?

So now, I'm running two 7.4V Lipos. When my low voltage alarm went off (at about 3.3volts per Lipo), the Lipos were hot and puffy. I'm running the Lipos from my Emaxx, so they are "hardcase". Either way, they looked puffy. HOWEVER, after they cooled down, they went back to normal size and received full charge once again. I always thought once Lipos were puffed, they were dead. But it doesn't seem to be so in this case.

So I'm really curious to see if anyone else had battery heat issues. I'm going to gear down to the 14t and see what happens. Anyone have similar issues?

[Jakey]

Yes, the two extra teeth could make that much difference. Boats can be battery pack eaters due to the high continuous Amp loads and lack of cooling air blowing over the packs. Your LiPo packs temporarily puffed which was the first warning they were not happy. Raise the LVA to 3.4 or even better 3.5 volts per cell and try again. Check the packs after only a few minutes of runtime and if they are overly warm gear the boat back down.

[M3Armand]

I just opened up the boat and counted the pinion gears. I was running the stock 14 tooth! Looks like my kit also came with 12 tooth. So now my question is, why would I have to gear down to 12 tooth especially when I'm even running the water cooling system for the motors?!!! This is odd!

[Jakey]

If 14 teeth is the stock pinion that Traxxas recommends, then no I am not saying you have to gear down. Water cooling the motors will help to prevent them from overheating. but this will not do much to prevent the battery packs from overheating. Maybe there is some drag in the system somewhere that is helping to create high loads on the motors and therefore the batteries.

Again, if the LiPo packs are very warm after running and/or temporarily puffed, they were exposed to excessive Amp loads or discharged too low or both.