Search found 39 matches

by BlueBell
Feb 15, 2018 11:13 am
Forum: General Discussion
Topic: Solar Kiteboat Electrical Needs
Replies: 5
Views: 152

Re: Solar Kiteboat Electrical Needs

Is this thread in the wrong forum division perhaps?
It is not actually an electric boat, that would be against the rules of the race.
Where would be a more appropriate place for this thread?
Thanks
by BlueBell
Feb 14, 2018 11:40 am
Forum: General Discussion
Topic: Solar Kiteboat Electrical Needs
Replies: 5
Views: 152

Re: Solar Kiteboat Electrical Needs

......
by BlueBell
Feb 13, 2018 12:03 pm
Forum: General Discussion
Topic: Solar Kiteboat Electrical Needs
Replies: 5
Views: 152

Re: Solar Kiteboat Electrical Needs

Moderator mess-up...
by BlueBell
Feb 13, 2018 12:01 pm
Forum: General Discussion
Topic: Solar Kiteboat Electrical Needs
Replies: 5
Views: 152

Solar Kiteboat Electrical Needs

I need some help completing the electrical design and purchase section of my boat build. I am doing final design and purchase while building the hull and I need your feedback on my electrical set up if you would. The race allows no motor so I have no alternator charging. Here's what I'm proposing to...
by BlueBell
Nov 28, 2017 2:12 am
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Cool, thanks DrkAngel!

We heard back from the prop guru and he thinks a 2-bladed, 13" x 20" pitch would work well for all the heats.
Even up to 22" perhaps.
Good luck trying to find one of those in the R/C airplane department...
by BlueBell
Nov 27, 2017 3:24 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

DrkAngel,
And the lipo, would it heat up during discharge like that?
Not likely or you would have mentioned it.
A spray bottle is not an option as the pilot is not in a position to operate it and too busy with other tasks anyway.
The copper tubing would have been the ticket.
by BlueBell
Nov 27, 2017 11:50 am
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

DrkAngel, Not overlooked, but thanks for your concern. That issue has been addressed. Don't forget, this set up only has to last about 30 minutes at peak performance. As you know, the loads aren't terribly high. We are, however, looking at copper tube, water cooling on the motor if need be. Thoughts...
by BlueBell
Nov 26, 2017 5:16 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Ohhhhh, that's what those graphs were all about, sorry, I completely missed the connection.
Is this motor selection far too big then?
Probably not or you wouldn't have recommended it.
Thanks for all your patience.
by BlueBell
Nov 26, 2017 3:12 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

999zip999
Sorry, you lost me there...
by BlueBell
Nov 26, 2017 11:35 am
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Okay, the plot thickens. I'm asking for propeller recommendations on a known boat forum and uncertainty has arisen over shaft RPM at reduced power levels. In the different heats there is either ~200 watts or ~400 watts available to the motor. What RPM's could be expected? I thought at 48 volts the R...
by BlueBell
Nov 22, 2017 7:07 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Thanks, good to know. Slow reverse is fine, maybe even good. It appears from the videos the direction of rotation is correct for a right hand propeller. This is good as there are way more of those to choose from than left handed propellers. Unfortunately, it's going to want to unscrew our threaded s...
by BlueBell
Nov 22, 2017 1:24 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Can we pick the direction of rotation on this motor or is it predetermined?
We are proposing to thread an aluminum tube onto the shaft threads of the motor.
If it turns counterclockwise, it will tend to unscrew our propeller shaft!
by BlueBell
Nov 16, 2017 11:40 am
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

DrkAngel,

I noticed the upper limit on the motor controller is 42.5 +/- 0.5 Volts.
Is this going to be a problem at 44.4V?
This is printed on the controller, the spec sheet differs, same for LVC.
by BlueBell
Nov 16, 2017 11:26 am
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

I know it takes a lot of energy to get the prop started So what is the amp draw of the controller and add a few ? So 12s 2p of Samsung 25r cells 25amp cell. Price is going down. Maybe 3.75- 4.00 usd each. Did you mean it takes a lot to get the motor going? I've been told we may have a problem when ...
by BlueBell
Nov 15, 2017 12:28 am
Forum: Electric Watercraft
Topic: Motor, Battery and Control Selection for Kids Race Challenge
Replies: 8
Views: 362

Re: Motor, Battery and Control Selection for Kids Race Chall

Sacramento.
Check out the original post on this thread.
See you there?
by BlueBell
Nov 14, 2017 8:00 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Lol, ok, graphene it is... even though it's lighter.
by BlueBell
Nov 14, 2017 7:41 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Yes, we are advised to have a second battery in case of poor weather and the solar-only heats will run on battery instead. But I thought you didn't like the first one, the HobbyKing R/C one. Graphene you say. Perhaps that has something to do with the differing three letter abbreviation associated wi...
by BlueBell
Nov 14, 2017 5:13 pm
Forum: Electric Watercraft
Topic: Motor, Battery and Control Selection for Kids Race Challenge
Replies: 8
Views: 362

Re: Motor, Battery and Control Selection for Kids Race Chall

Thanks Fechter.

The battery will be mounted in the boat.
So long as we don't drop the boat, we should be okay.

The race is held in California in May.
by BlueBell
Nov 14, 2017 4:59 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

Ah, yes indeed, you did show me that, thank you and my apologies for overlooking it.
I've just read through the thread a few times and believe I'm getting a firm grasp on reality, finally.

So, 25C constant with 50C burst isn't okay?
You pick one. :)
by BlueBell
Nov 14, 2017 2:44 pm
Forum: Electric Watercraft
Topic: Motor, Battery and Control Selection for Kids Race Challenge
Replies: 8
Views: 362

Re: Motor, Battery and Control Selection for Kids Race Chall

We've switched our proposed battery to four of these in series in an effort to keep the voltage down through the charger: https://hobbyking.com/en_us/turnigy-battery-nano-tech-4000mah-3s-25-50c-lipo-pack-xt-60.html Would you like to comment before we go ahead and order these along with the motor: ht...
by BlueBell
Nov 14, 2017 2:24 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

"Sona 18650 cells may not qualify due to lack of documentation-verification of capacity." Yes, you hit the nail on the head there. They require documentation of battery specs. Max 180 Watt-hours Not sure which Turnigy 4000 you meant. This one: https://hobbyking.com/en_us/turnigy-battery-nano-tech-40...
by BlueBell
Nov 12, 2017 9:52 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

DrkAngel, I'm really starting to feel like an idiot here. Not really sure what you're trying to beat me over the head with. It looks like four different battery options...? Is that right? Is the C-number relevent here or are they all the same? Knowing our requirements, is there one combination you w...
by BlueBell
Nov 11, 2017 4:08 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

DrkAngel wrote:Sonas @ $150 per 100 cells = 4 x 24 cell battery builds
OMG, you should see what I get when Googling this!
Can't seem to find Sonas lipo's on-line...
by BlueBell
Nov 11, 2017 2:15 pm
Forum: Battery Technology
Topic: Battery Advice Needed For Middle School Competition
Replies: 90
Views: 2674

Re: Battery Advice Needed For Middle School Competition

This is fantastic guys, thank you.

I should have mentioned earlier, we have a $1000 budget for the project...
Batteries can get pricey...