BBY's 1/8 Pro Boat build

[skellyo]

in order to do that you would have to have 10c 5,000 lipos- for 20c 10,00 2p

2 10c pack in parallel = 20c

40c packs in parallel would make 80 c , do you get it?

That's incorrect. C rating does not change based on cell configuration. Capacity is what changes when paralleling cells.

2 X 20C 5000mAh packs (100A) in parallel = 1 X 20C 10000mAh pack (200A)

[6S HYDRO]

10,000 mah 40c

[6S HYDRO]

That's incorrect. C rating does not change based on cell configuration. Capacity is what changes when paralleling cells.

2 X 20C 5000mAh packs (100A) in parallel = 1 X 20C 10000mAh pack (200A)

when you parallel cells it doubles the mah capacity and the c rating

[skellyo]

when you parallel cells it doubles the mah capacity and the c rating

No it doesn't. Capacity doubles, C rating is a constant, always. If you put down the math behind what you're saying, you believe that the continuous current capability of a pack quadruples when you put two packs in parallel....that's not correct.

Based on what you're saying:

Incorrect method...
20C 5000mAh pack = 100A continuous current capability
2 X 20C 5000mAh packs in parallel = 40C 10000mAh = 400A


Correct method...
20C 5000mAh pack = 100A continuous current capability
2 X 20C 5000mAh packs in parallel = 20C 10000mAh = 200A

You see the basis behind all of this is that the C in C rating is the capacity. The multiplier ahead of the C in C rating is a constant, always. Double the capacity, the continuous current capability doubles, triple capacity and the continuous current capability triples and so on.

[6S HYDRO]

the amps doubled

[skellyo]

the amps doubled- the c rate doubled

No, the capacity doubled, not the C rating of the cells. A 20C cell is always a 20C cell no matter what kind of pack configuration you put it in. That single cell can only handle a specific amount of continuous current draw and that value never changes.

[6S HYDRO]

im not goin any further on this, its off topic for Randy's thread

[Brushless55]

I was wanting to use 20c lipo's instead 40c lipos, to save some cash . But still have 10,000 . So what would that be using 4 5,000 20c packs ?.

just my opinion, if you want to save some cash maybe a different boat?
this is a big amp motor that should be backed by some good packs that can deliver the amps..
I would split the difference and go 30c packs.

[rchippie]

just my opinion, if you want to save some cash maybe a different boat?
this is a big amp motor that should be backed by some good packs that can deliver the amps..
I would split the difference and go 30c packs.

If it really needs the better packs then i will buy them . I was just checking if the other one's would be enough .

[Brushless55]

better to have more that just enough for high amp motors..
your batteries will thank you for that

[Jeepers]

better to have more that just enough for high amp motors..
your batteries will thank you for that

any motor can be a high amp motor, I saw a UL1 motor take out a Hydra 240.

[Rumdog]

That littlescreamers outrunner should have fairly low amp draw being that it's only 650kv I believe.

[Jeepers]

when you parallel cells it doubles the mah capacity and the c rating

wrong skellyo is correct. the c rating stays the same.

here read carefully. I can search more to show you if you want

http://www.rcgroups.com/forums/showthread.php?t=209187

[Jeepers]

That littlescreamers outrunner should have fairly low amp draw being that it's only 650kv I believe.

also depends on how its propped, how wet the hull is running etc.

[Brushless55]

That littlescreamers outrunner should have fairly low amp draw being that it's only 650kv I believe.

these motors can pull alot of amps
on their site they have ratings of 88watts to 160watts +, depending on application