Tuesday, August 02, 2022

SAR boat on the water


Batteries charged, it's time to take the pilot boat to the lake and see how it handles. First though, I tie the superstructure to the hull with a length of wire. It's held in place with magnets, which seems pretty good, but I prefer this belt and braces approach on all my models. If the top comes off, you can always tow it home. 

Fired up, the boat actually works. 

But not very fast, or for very long. It moves OK, but not as rapidly as I'd have hoped. Worse, the duration was about 5 minute sfrom one pack and 3ish from the other. OK, neither pack might not have taken a brilliant charge, but I need to look at this. 

The battery pack used is a six-cell (7.2v) 2000mAh Ni-MH set and I think the solution will be more volts and more amps.Looking at the maximum capacity of the speed control, we could be good for twice as many cells, so a bit more omph should up the top speed. 

However, I'm wondering if it's time to take the dive into a LiPo battery for this boat. More power for less weight is very appealing, but I've always fought shy of them. Techincal and possible to explode, neither appeals much.


Jody said...

I pleased to see your boat works but a shame it's slower than you expected and didn't run for long. I use lipo batteries for several RC applications, as long as they are charged correctly and also stored at the correct voltage they are safe as any other battery. However I do have a RC crawler that my kids use and as a precaution that uses a nimh battery as that way if it's over discharged or left flat there won't be any issues next time the battery is charged or used
If you only need the battery to be used infrequently then I'd suggest a nimh battery. Overlander do some 5000mah packs for not much money.
I'd also suggest considering using XT60 connectors in place of the Tamiya style connectors, to he Tamiya connectors are very poor at flowing good currents, they can also weld themselves together with high current draw applications.

Phil Parker said...

Thanks Jody. I've had a quick look at the site and there is a perfect looking battery there. I just need to find the right connectors for the charger and I'll get an order in.