[NSRCA-discussion] Going Electric - Battery Questions

Sun Dec 9 14:33:16 AKST 2012

Larry, 

I've just finished my second year flying electric in Intermediate.  Here's the throttle curve I've been using on my SD10G: 

Point 1     -85% 

Point 2     -56% 

Point 3     -15% 

Point 4      24% 

Point 5      58% 

Point 6      71% 

Point 7      82% 

Point 8      92% 

Point 9      97% 

I'm flying a different motor than you, an Axi 5325/24, but it's still an outrunner, so this throttle curve should give you a starting point. 

I flew Blue LiPo 20c 5000s last season with good success, but switched to Sky LiPo 40c 4400's this year, mostly because they were on sale.  I've been happy with them too, but this particular curve may be just a little 'hot' at the top end, especially when I get excited.  There's a big difference between new 40c's and 20c's nearing the end of their useful life. 

The 4400's give me enough to fly the sequence and a couple of 'do overs' in practice without going too deep into the batteries. 

I typically use between 2500 and 2800 mAh in a contest flight but have gone as high as 3200 flying large and far out on a windy day and as low as 2100 when I fly (too) slow. 

Hope this helps, good luck, 

Scott 

----- Original Message -----

From: "Joe Lachowski" <jlachow at hotmail.com> 
To: "NSRCA Discussion List" <nsrca-discussion at lists.nsrca.org> 
Sent: Friday, December 7, 2012 3:14:54 PM 
Subject: Re: [NSRCA-discussion] Going Electric - Battery Questions 

5000's or better are the best way to go no matter what schedule you fly. They will last longer and won't get as hot. Unless you have a weight problem, 5000's or better at 25C or 30C are the way to go.  Besides you can then safely throw in an extra few practice maneuvers. Also, 5000's can afford you the flexibility to have and  fly a smaller practice plane on 5S like the Monolog 70, Osiris, Angel S, or Wind S in addition to your 2M ship(s). 

> From: vanputter at gmail.com 
> Date: Fri, 7 Dec 2012 13:53:39 -0600 
> To: nsrca-discussion at lists.nsrca.org 
> Subject: Re: [NSRCA-discussion] Going Electric - Battery Questions 
> 
> This is a refreshing discussion. I have been telling people for years that they don't need continuous discharge 35C, 45C, etc batteries because they would NEVER use it. The response I often get is, "Well, more is better". Certainly more $$$. The Scottish ancestry blood in my veins boils when I hear that. 
> 
> Another thing that torques me is when Sportsman and Intermediate pilots insist of getting 5000mah packs because that's what the "big boys" use. I keep trying to tell them that any capacity more than about a 33 % reserve above what their maneuver schedule requires is dead weight that shouldn't be carried around. 
> 
> Ron 
> 
> On Dec 7, 2012, at 1:18 PM, Atwood, Mark wrote: 
> 
> > Hey Larry, 
> > 
> > As everyone is telling you, the BIG difference between what you're proposing and what you're accustomed to with Glow is that you'll fly 90% of your sequence at half throttle. Not figuratively half throttle... but literally half, or below. Even a vertical upline does not need full motor on these setups. Flying intermediate even less so. Also, at full throttle you'll likely only pull about 75amps, so even 15C batteries would get the job done, but I would stick with 20 and higher. 
> > 
> > 
> > Mark Atwood 
> > Paragon Consulting, Inc. | President 
> > 5885 Landerbrook Drive Suite 130, Cleveland Ohio, 44124 
> > Phone: 440.684.3101 x102 | Fax: 440.684.3102 
> > mark.atwood at paragon-inc.com<mailto:mark.atwood at paragon-inc.com> | www.paragon-inc.com<http://www.paragon-inc.com/> 
> > 
> > 
> > 
> > 
> > On Dec 7, 2012, at 1:37 PM, Larry Diamond wrote: 
> > 
> > OK, play nice... Never dealt with electrics before... I could be way off base, but here is a stab at it... 
> > 
> > Is my math flawed? 
> > 
> > Motor - Himax 6330-210 F3A Motor (210KV) 
> > ESC - Phoenix Ice 80HV - New V2 Version 
> > Battery 10s - 37VDC 
> > 
> > Plane - 2M Monolog 
> > 
> > Max power range is about ~2,700 to ~3,000 watts with this set up... 
> > 
> > Calculated Battery Discharge Rate = 80Amps (ESC rating) divided by 3,500mAh (battery capacity) = 22.9C 
> > 
> > Based on this math I suspect that a 30C dicharge rate is good on paper... additional discharge performane = $$$ and I don't want to spend money on battery performance I don't need... 
> > 
> > Class - Intermediate 
> > 
> > What is the recommended battery capacity and discharge rate...? 
> > 
> > I understand the many variables associated with the answer like, prop size, temps, wind, throttle control, yada, yada, yada... 
> > 
> > I would like to fly the Intermediate sequence a couple time without having to refuel electrons... 
> > 
> > Larry Diamond 
> > _______________________________________________ 
> > NSRCA-discussion mailing list 
> > NSRCA-discussion at lists.nsrca.org<mailto:NSRCA-discussion at lists.nsrca.org> 
> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion 
> > 
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