[NSRCA-discussion] E Stuff

Chad Northeast chad at f3acanada.org
Sat Jan 21 13:51:57 AKST 2006


Vincente

The only guarantee is you will get 1 cycle :)  I have the TP 5300's 
which have 70 ish cycles on them with my Plett 30-10 (62A peak 
static)...some guys in France (Matt's for sure) had over 100 on those 
packs.  With my wattmeter I cannot distinguish a difference in voltage 
under load now compared to new, but they would have some degredation (I 
dont have a CBA to check).  Adam was running 6000 prolites and measured 
about a 3.5% decrease in capacity over 50 flights or so (he can correct 
me if my memory has failed)....so you can approximate a life of them 
from that.  Another fellow (cant remember his name) posted his capacity 
degredation values on RCU in the electric pattern forum...I seem to 
recall that he had better life than Adam for the same amount of flights.

I think 250 cycles is out of the question for todays stuff, at least 
still retaining enough performance.  Charlie has posted on RCG that 
70-75 cycles can be expected when ran to the max (so 90ish % discharge 
and max C rating)....our applications are not that tough on batteries 
but we are not soft enough on them to get 250!  Ultimately the cycle 
life depends on how you treat the packs....abuse them and they will fail 
very quickly. 

This is all still very experimental, its getting better with more and 
more people flying the e setups and finding what works and what 
doesnt.....but dont get into it thinking you are guaranteed a certain 
number of flights from a pack.  You could just as easily get 10 flights 
as 100 :)  My advice to anyone is if money is of remote concern tread 
lightly.....as this can get very expensive in a very short period of 
time!  Its no different than starting out in the hobby from scratch.  
Beyond that if you do get into it, take a setup that is very proven with 
a lot of flight time on it....let those with deep pockets and good 
backing from companies do the experimenting for you :)  Doing R&D on 
your own dime can leave a bad taste in your mouth!!!

Anyways, I plan on continuing to run my 5300's this year until they 
fail.  I am also going to buy another set so I can compare old ones 
directly to new ones in flight.  This way I will have a good idea of 
what can normally be expected.  Since they have a shelf life and we dont 
fly much over the winter I want to know how big of an impact that is 
going to have....or if I should try to sell them after each season.

I think Earl's post hit some excellent points on the flying.

Chad

vicenterc at comcast.net wrote:

> Jerry,
>  
> Today we got two e-mails.  One with 30 cycles the other over 170.  At 
> the Nats. a very well know pilot told me 60 average.  As we can see, 
> it is all over the map.  I would like to go electric and the 
> advantages of electric power in pattern are evident.  However, I am 
> not ready until battery companies give us some minimum expectation in 
> regard battery life.  Clearly time will tell.  I believe that when we 
> start to see the power tools manufacturers installing LiPo in their 
> equipment we would be able to expect a decent life of this packs under 
> high current draw conditions.
>  
> Vicente Bortone 
>  
>
>     -------------- Original message --------------
>     From: "Jerry Stebbins" <JAStebbins at worldnet.att.net>
>     Vicente, I hope that is "tongue in cheek", because any battery
>     manufacturer to warranty to that, or almost any extent would be
>     killed by his/her lawyers. They would have so many "exceptions"
>     that they would "never be at fault".
>     If that is anyone's criteria it wll be a long time before they switch.
>     Jerry
>
>         ----- Original Message -----
>         *From:* vicenterc at comcast.net <mailto:vicenterc at comcast.net>
>         *To:* NSRCA Mailing List
>         <mailto:nsrca-discussion at lists.nsrca.org> ; NSRCA Mailing List
>         <mailto:nsrca-discussion at lists.nsrca.org>
>         *Sent:* Saturday, January 21, 2006 2:51 PM
>         *Subject:* Re: [NSRCA-discussion] E Stuff
>
>         Scott,
>          
>         I am waiting for my second Abbra.  If Tanic gives me a written
>         warranty that the battery is going to last around 250 cycles
>         of Master rounds I will make the switch.  Is that possible?  I
>         will follow charging and break in instructions.
>          
>         Thanks 
>          
>         Vicente Bortone 
>          
>
>             -------------- Original message --------------
>             From: "Scott Anderson" <scott at rcfoamy.com
>             <mailto:scott at rcfoamy.com>>
>             Vicente,
>              
>             You also have to look at replacing bearing, changing
>             batteries in the support equipment (glow driver/ electric
>             starter) and servos after a time from vibration, this will
>             increase your glow cost per flight .. Dan Landis and I are
>             using Tanic packs and he flies FAI and has a set of sticks
>             ( Battery) with over 170 flight and you can't tell the
>             diffrence from that pack and on with less time on it.. I
>             have just started using Tanic and the results are very
>             good, Just follow there "breakin" for the packs.
>             I made the jump to electric in 05 and after the first
>             flight I was hooked and sold all glow fuel and glow
>             planes.. If you look around you still make the conversion
>             without  breaking the bank.
>              
>             Just my 2 cents
>              
>             Scott Anderson
>             D3 AVP nsrca 529
>             Team Tanicpacks.com
>             Team PMA
>              
>              
>              
>              
>             ----- Original Message -----
>
>                 *From:* vicenterc at comcast.net
>                 <mailto:vicenterc at comcast.net>
>                 *To:* NSRCA Mailing List
>                 <mailto:nsrca-discussion at lists.nsrca.org> ; Discussion
>                 List, NSRCA <mailto:nsrca-discussion at lists.nsrca.org>
>                 *Sent:* Saturday, January 21, 2006 1:35 PM
>                 *Subject:* Re: [NSRCA-discussion] E Stuff
>
>                 Unfurtunetely, I have to estimate the cost.  I did an
>                 estimate how much is the cost to run my 2c motor per
>                 flight.  At $15/gallon using 14 oz of fuel per fly the
>                 cost is $1.75 per flight.  This number is correct
>                 since I usually flight between 200-300 flights per year. 
>                  
>                 The question is: what is the life of the batteries? 
>                 Base of the feedback I got at the Nats. the life
>                 flying F3A is around 60 flights.  Therefore, if I am
>                 correct the cost per fly is $11.  Assuming that I do
>                 250 flights per year the cost of electric is
>                 $2,750/yr.  The equivalent cost of glow (2C) is
>                 $440/year.  With two kids in college my option is
>                 clear.  I am assuming that the cost of batteries is
>                 $640 but not sure now. 
>                  
>                 Probably I am wrong in these numbers.  Clearly the
>                 cost of the batteries has to come down or the cycles
>                 have to go up to around 400 cycles to get equivalent
>                 cost to glow. 
>                  
>                 Any information on this regard is welcome,
>                  
>                 Vicente Bortone
>                  
>                  
>                  
>                  
>
>                     -------------- Original message --------------
>                     From: "Earl Haury" <ehaury at houston.rr.com>
>                     The E info on the list has been scant. Probably
>                     some are reluctant to hype / criticize products
>                     because of their involvement with suppliers. Some
>                     of us are just blindly exploring options,
>                     gathering data / information, and forming opinions
>                     without experience to back up our conclusions.
>                     Certainly information offered by those with
>                     experience is very welcome and appreciated. Those
>                     who are qualified experts in the various fields
>                     that can correct / clarify information gained
>                     through the school of hard knocks are not only
>                     welcome, but I suspect somewhat obligated to
>                     protect the rest of us. As this entire topic
>                     expands there will be conflicting opinions which
>                     in themselves provide info - that's what this list
>                     is for and no one should take offense that some
>                     prefer other views.
>                      
>                     After teasing the E guys at the Nats I recognized
>                     that the E powered airplanes flew better (I'll
>                     admit to being obstinate - but not totally dumb).
>                     There were also differences that seemed related
>                     more to E equipment choices than differences in
>                     pilot skills. The info published by Jason, Frack,
>                     Adam, Chad, and others (in RCU forums) provided an
>                     insight to the various equipment choices (and
>                     passionate defense of same in some cases).
>                     Interestingly, a lot of the discussions revolve
>                     around equipment type rather than the effect on
>                     flight characteristics.
>                      
>                     So - I set about trying to determine if E flies
>                     better and why. So far the answer is yes and I'm
>                     not sure. While differences in dynamics can be
>                     identified, it's hard to quantify the effects. For
>                     example, the lighter / slower rotating E prop
>                     generates a lower gyroscopic precession force
>                     during looping maneuvers than glow - this also
>                     suggests the lower rotating mass of a geared motor
>                     might be better. The lighter motor (compared to
>                     glow engine) up front can result in a lower pitch
>                     moment of inertia if the tail is light enough to
>                     allow the battery mass to be close to the CG.
>                     Airplane smoothness in rough air is markedly
>                     better with E. (I did most of my comparisons with
>                     twin Partners - one glow and one E - at about the
>                     same flight weight.)  This may be an effect of the
>                     large diameter prop or lack of vibration effect on
>                     the servos. As others have noted, thrust
>                     application is very good with E as the slower prop
>                     is efficient and the mo! ! ! tor is instantly
>                     responsive and very linear. E can be flown slower
>                     than or as fast as glow, the airplane is more
>                     stable with E when slow  - again probably the
>                     large prop effect. Overall, it's easier to fly
>                     well with E but E won't fix sloppy flying.
>                      
>                     As with most things in model aviation - there are
>                     learning curves. Some suppliers are better than
>                     others, some equipment is better than others, some
>                     choices will be revisited after experience is
>                     gained. The hardest thing to get used to is the
>                     metrification of cost - kilo dollars. Not that E
>                     is that much more expensive than glow - just that
>                     very little from glow is useable with E. That
>                     means one must acquire motors, controllers,
>                     batteries, chargers, power supplies, meters,
>                     connectors, wire, props, etc. pretty much from
>                     scratch.
>                      
>                     If there's interest in this becoming a thread I'll
>                     discuss the reasons for some of my choices of
>                     equipment and the data I've generated / will
>                     generate with the full understanding that I might
>                     be operating under false assumptions and some of
>                     this stuff will change - I'm still learning.
>                      
>                     Earl
>                      
>                      
>                      
>                      
>                      
>                      
>                      
>
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> ------------------------------------------------------------------------
>
> Subject:
> Re: [NSRCA-discussion] E Stuff
> From:
> "Jerry Stebbins" <JAStebbins at worldnet.att.net>
> Date:
> Sat, 21 Jan 2006 21:30:46 +0000
> To:
> "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>
> To:
> "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>
>
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