cat question

[rcboatfan]

how would two aquacraft ul-1 power combos push a 36 inch cat on 4s LiFe for each motor? thanks

[sailr]

No. You would need to use 5S LiFe. They are only 3.2V per cell vs. 3.7V for Lipo.

[rcboatfan]

ok so on 5s LiFe would be good> what kind of speeds would i get?

[Flying Scotsman]

What cat, what props, what ESCs, what speed do you desire and run time? A single drive will be less expensive

Douggie

[rcboatfan]

i got the plans from lomdel, x442's, aquacraft ul- 1 esc's, and maybe 45mph ish and run i geuss as long as posible

[Flying Scotsman]

That is a big cat, I have no experience on that size of hull, maybe others will chime in with more expertise. It will be expensive regardless of the power choice and expected durability of components

Douggie

[Jesse J]

36" aint so big... Personally, I would use BJ motors instead (5-6S LiFe), but that's just me. I am pretty sure they will work great together to push that kitty.

[sailr]

One of the properties of LiFe batteries is they will SINK like a rock if you try to pull the juice out of them too quickly. Then your ESC will sense a low voltage situation and shut down. A friend of mine in China is an engineer with the biggest manufacturer of lipos, life's, etc. He confirmed this. The way I know is that a friend of mine was having problems with his airplane. As soon as he jammed it to full throttle, it would shut down. If he went back to low throttle, the battery and esc would recover. He could fly so long as he slowly applied throttle., I told him to switch to Lipos and see what happens and everything was perfect. Naturally we suspected the LiFe battery. I emailed my friend in China and he said YES, this is a problem with LiFe batteries.

If your application doesn't demand too many amps all at once, the LiFe will work OK. Some of the boat racers in Europe are using them successfully in small boats with small motors that don't draw so many amps.

[rcboatfan]

ok thanks so lipos would be better