SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Jul 07, 2012, 04:10 PM
I think I'm inverted. Maybe.
acetech09's Avatar
United States, CA, Pacifica
Joined Apr 2012
1,509 Posts
Discussion
How long do you like to fly your hotliner?

Simple quick question and discussion: What kind of battery times do you like to get out of your non-competition hotliners? I normally weigh down my planes heavy with larger battery packs to extend flight time while I'm teaching myself maneuvers or just buzzing around. I think that I'm a tad eccentric - I find myself always worrying about fuse radius due to the maximum width of battery I can fit into it.
acetech09 is offline Find More Posts by acetech09
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 07, 2012, 05:13 PM
Tim Lampe; Hobbico R&D
KRProton's Avatar
Champaign, IL
Joined Dec 2009
3,774 Posts
I just completed my Great Planes Siren last week. I have three flights on it. Airborne at full-throttle it pulls about 40A on average. This works out to about 3 minutes of motor run time (given full-throttle bursts) to use 80% of a 2700mAh battery (which is 2160mAh). Stated another way this is about 700mAh per minute.

Looks like this should work out to about at least fifteen minutes of air time.

More figures in my Siren blog entry in my blog.

Tim
KRProton is online now Find More Posts by KRProton
RCG Plus Member
Old Jul 07, 2012, 06:32 PM
Registered User
Mreyello's Avatar
Deutschland, RP, Niederzissen
Joined Dec 2011
870 Posts
The runtime of hotliners which deserve to be designated as hot usually is limited by the waste-heat the drive can take.
Adding battery capacity would be expensive() and would reduce performance due to higher weight and bigger fuses with higher drag.

To encrease runtime means to reduce power.

Its your choice what you like more: Less fun for longer time or more fun for shorter flights

Yello
Mreyello is online now Find More Posts by Mreyello
Last edited by Mreyello; Jul 07, 2012 at 06:46 PM.
Reply With Quote
Old Jul 07, 2012, 07:51 PM
Registered User
United States, VA, Manassas
Joined Dec 2007
120 Posts
Flying a hotliner is a very different way to fly. I try to put a battery that has as much capacity as I can also, but have found it unneccesary. My set up is an Enigma w/ a 1512/1.5D/6.7 18x21 and one battery is a 4S TP5000 65c (2400 watts)and the other is a 5S Genesis 4200 (3200 watts). Motocalc predicts 1:25 total run time for the 4s 5000 and right at 1 minute TOTAL run time for the 5S 4200. A typical flight is 3-4 second burst at launch. Slow speed entry (100mph or less) into a climb, a 2 second burst will put you back up to 5-700 feet. If you climb, dive and cross the field at high speed straight into a climb, a 1 second burst is all you need. Spending 20 to 30 seconds between bursts and 12 to 15 bursts to climb is a LOT of flying and I always have 60 -70% battery left. You could easily spend 3 minutes or more between climbs which is a tremendous amount of time if you climb 12-15 climbs. I repeat, 2-3 second motor bursts will sling you almost out of sight each time! I will defer to the more experienced hotliner pilots to answer as I have only had 35-40 flights on mine. I understand that you never want to use more than 50% of your battery capacity during a flight.

Brooks
bpbrinson is offline Find More Posts by bpbrinson
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion How Do You Like Your Eggs? Real Ira Life, The Universe, and Politics 52 May 23, 2013 08:25 AM
Discussion How do you know when your springs are "right" Bugman Jeff Off-road Cars 2 Jul 11, 2012 04:52 AM
Discussion How do you tell a flyer he's too old to fly? zeezee Electric Plane Talk 75 Jul 04, 2012 09:38 PM
Question Where do you get your trim designs and how do you test them? dedStik The Builders Workshop 16 Mar 15, 2012 03:32 PM
How long do you fly a your model before you get bored and build/buy a new one? totalboss Electric Plane Talk 51 Jun 10, 2010 12:53 AM