more Qs... Batteries & Run Times

[Doby]

Wilson; You are alive,,,,excellent.

Yup, I run the same set up in my Blackjack, Llumar and SV, all on 4S. All using the stock SV prop. Its a great combo!

[motoxbob11]

Hey JMH not to disappoint you but you will never see 20 minute run times with this hobby right now! Reasonable thinkin 5 to 7 minutes once you have it dialed in and thats wide open throttle!

Gas or Nitro running you will but not with Fast Electrics!

Be advised that brushless motors and esc's do not like partial throttle running ... too much heat buildup! And heat is your enemy!!!!

I agree completely. We expect too much performance to get long run times from a small electric motor. If you want to drive around for 45 minutes you can get a weedeater motor gas boat. They are great boats.
As far as an SV I run for 5 minutes with a stock setup and a cf 45 prop and 4800 lipos. I takes about 2500 mah to recharge them so I'm not even close to discharged but I like it that way. The fact is we spend a lot more time fiddling with these boats than actually driving them but oh boy is it fun when we do!

[domwilson]

Yes Doby, I'm still alive. It's a good thing too...

Ya think it might work with an x642?

[Doby]

Don't know,,,,,,,try it and let us know.

[domwilson]

But I'm scared.

[domwilson]

How about a x640? an x637?

[jmh2002]

I run for 5 minutes with a stock setup and a cf 45 prop and 4800 lipos. I takes about 2500 mah to recharge them so I'm not even close to discharged but I like it that way.

THANKS! for the info. However this is kind of what I am getting at. If you take the boat out for a even 30 minutes you must have multiple sets of of batteries, no?

So, is everyone running around with $1000 worth of batteries, or? Surely you dont go home again after only 5 minutes use?

[Rex R]

not quite that much in batteries...tho I do (usually) bring about 4-5 chargers :-) (and 2 power supplies), I am fortunate to have 120v availible on site for charging.

[jmh2002]

As far as an SV I run for 5 minutes with a stock setup and a cf 45 prop and 4800 lipos. I takes about 2500 mah to recharge them so I'm not even close to discharged but I like it that way.

Based on the above scenario, which would seem like quite a common set up, am I correct in thinking that to put that 2500mah that was used up in 5mins back into the battery, it would take, charging at 1C / 0.48amps (please correct me on this?) about 5 hours?

Or do I have my maths mixed up?

Is it a good idea to charge them in parallel to double the capacity (even though in the boat they are in series, to diuble the voltage) in order that a higher charging curremt can be used, and therefor a faster charging time (ie: about half the time)?

THANKS!

[Rex R]

at 1c (4.8 amps, darn those slippery decimals) it should take no more than an hour...given usual charging rates(observed) figure about 40-45 minutes to put 2500mah back into the packs.

[jmh2002]

Ok, thanks.

I thought I had my maths wrong.

Either way, it would seem that at least 2 sets of batteries are required, and if they are Lipos, its starting to get a bit on the pricey side $ spent vs fun hours returned, which is a bit of a shame.

Ill mull it over some more I guess.

[motoxbob11]

Yea it is a shame but we are just making sure you know what the deal is. You need a couple sets of packs and hopefully a couple chargers (or a duo) to do it for any length of time

[Doby]

http://s167.photobucket.com/albums/u145/dobydog6507/?action=view&current=JulyMillerLake029.flv

Heres a link of mine in some rough water, its fun but you do have to be careful.

[motoxbob11]

Not only careful about flipping the SV but those darn fish keep biting my leg also!
A couple of nice saves there Doby and it really shows how tough it is going into the waves as opposed to running with them.

[Doby]

Running with the waves is a blast, It turns into a submarine a few times.
The saves were from devine intervention, not driver skill.

The fish turned out to be minnows about 3 inches long!