Need help on 12s setup

[Mel279]

hi guys

I need you guys advise on my 12s setup twin cat 135(54")

Motor: 2 x Leopard 5692 / 730kv

Esc: 2 x SF HV 240A

Prop: CR 447's ...thats the only one I have.

I was thinking of getting some Gens ace 6s 25c 5500mah and will be set in series for 12s. I would like to know is the c rating enough for that setup without the lipo getting hot and puff.

[Fast Guy]

Keep in mind that the 25c rating is very conservitive on the Gens Ace and in tests I have seen they should be rated at 40c. Get yourself a data loger like a Eagletree and do short runs till you get it sorted out.

[jcald2000]

NO!!, 45C min.

[Mel279]

NO!!, 45C min.

ok thanks, but do you ever run a big twin cat with 12s before?

[Fast Guy]

I don't know how much HP you need to get that big cat going but your 25c 5500ma batteries are going st give you 137.5a and at 44.4v thats going to make 8HP. Your batteries fully charged are going to be 50v and that makes over 9HP. A full sized man in a 12ft boat with a 8HP outboard will get up on plane so I think your cat should too. Not sure where the need for 45c is comming from.

[Mel279]

From what I know, high voltage require less amp draw, the higher the voltage, the lower the amp, Im not sure about that. But anyway, thanks for your advise.

[U1Racing]

remember what they say about electricity: it's not the voltage that will kill you, but the amperage will. trust them when they say 40c at an absolute min!! the fact that high voltage has less amp draw still doesn't prevent you from having a 5-second current spike!!

[Fast Guy]

From what I know, high voltage require less amp draw, the higher the voltage, the lower the amp, Im not sure about that. But anyway, thanks for your advise.

You are correct in your thinking. Thats why you see hi voltage in high output systems. What you need to be concerned with in electric power systems is the watts (volts x amps) which = HP (746 watts = 1HP). If you do a search you should be able to find out how many HP you need for your boat. From there you can multiply the number of HP by 746 watts to get the power system you are going to need.

For example if you need 5HP
5HP x 746w = 3730w
3730 divided by 44.4v = 84a on 12s
3730 divided by 22.2v = 168a on 6s

You also need to to try to get your max prop RPM between 25000 and 35000.
Your 730kv motor on 12s is going to be a very hot setup at 32412 RPM. High RPM means smaller props and touchier setup. The amperage your motors can handle also comes into play. Too much and they will overheat. If it works out for you you are going to have one fast cat.

[drwayne]

Gens Ace also produce a 40C5000 cell.

[Mel279]

Gens Ace also produce a 40C5000 cell.

thanks, I don't see that coming

[Fast Guy]

Gens Ace also produce a 40C5000 cell.

In tests the 25c Gens Ace performed better than a lot of 40c batteries including some big name brands. Makes you wonder if their 40c cells are going to be 80c.

[Mel279]

In tests the 25c Gens Ace performed better than a lot of 40c batteries including some big name brands. Makes you wonder if their 40c cells are going to be 80c.

Thinking of getting them instead, let see how it goes

[drwayne]

and 45/90 and 55/110...
55/100 at a max of 3300mAh
45/90 max 6400mAh ... thats 288A cont ....
They had lots on show at the Beijing Hobby Expo .....
:dreamysmile:

[Mel279]

and 45/90 and 55/110...
55/100 at a max of 3300mAh
45/90 max 6400mAh ... thats 288A cont ....
They had lots on show at the Beijing Hobby Expo .....
:dreamysmile:

drwayne

are those 6s lipo c rating?

[drwayne]

separate cells .. combine into packs yourself.
They offered assembly, but their QC was average for small qty sub 50packs.
Yes, I have trialed them. Work a treat.