Fw: Electric F3A

[Grow Pattern]

More good data - thanks Chad.

----- Original Message ----- 
From: <CNortheast at bjservices.ca>
To: <pattern4u at comcast.net>
Sent: Thursday, September 22, 2005 12:01 PM
Subject: Re: Electric F3A


>
> Hi Eric
>
> Please forward to the list as I cant do it from work :)  Just some of my
> comments about my experience, which has been good.
>
>>I was told 700 + great flights - So I then ask, at what cost? Was it 20
> packs? The cost, unless sponsored, is around $700 a pack (2 sticks). How
> deep are your pockets folks?
>
> I have about 400 flights on my setup, x4 Thunder Power 10s4p 5300 packs,
> approx 60 cycles.  That doesnt add up to 400 flights.....I used some
> Apogee's earlier in the season which were not surviving beyond about 30
> cycles mainly due to the discharge rating being too low.  The new TP packs
> though are working very well and I fully expect them to last 100 cycles at
> least.
>
> >How long did the packs last? Was it months or more like just a few weeks?
>
> When I say how long I really mean how many cycles. Talking to experienced
> electric FAI users I get numbers like 40-60 on the 8000mAh packs, but
> better
> on the newer ones. Even at the claimed two flights per charge that's still
> pretty expensive!
>
> I only get 1 flight per charge on 5.3 Ah packs.  I have been flying the
> TP's steady since about July 1 of this year.
>
>>Would they be good after a winter of none flying. Could not
> get an answer there at all.
>
> No idea, although I may find out this winter!  Yes Li-po's do have a shelf
> life and degrade over time.  I think the reason there is no answer for 
> this
> is because the earlier generation packs would not last long enough to test
> this out.  The newer packs can make it through a whole season now so we
> might start seeing some reports on loss of capacity from sitting around 
> for
> extended periods.
>
>>Then I got into how many motors have been in Tony/Jerry's plane to get
> that
> many flights. How many repairs to motors for whatever reason.
>
> I dont run the Hacker, and never will because of the gearbox maintenance
> required.  The Plettenberg motors that I use required no maintenance from
> me, in theory they should last for 1000's of flights provided you dont
> overheat them.  I put 400 flights on my motor without a single failure of
> problem of any kind.
>
>>I then got into how many packs you need to take to the field for a
> practice
> session or a local contest. That obviously depends upon how many chargers
> you have. I used to use three 109's. I saw most using 5 chargers and two,
> three or even four, deep cycle batteries
>
> I have 4 packs, 2 Schulze isl6-330d chargers.  At the field I use either a
> single 28 Ah deep cycle battery, or my car running to charge.  I typically
> only do 5 flights so that means 1 charge.  I can get 2 charges out of the
> deep cycle before its dead.  At contests there is usually a generator so I
> run PC converted power supplies (40A) that I got off Ezone for $18.  It 
> can
> power both chargers with enough juice to charge x2 10s packs @4A.  Thats
> enough to keep you going non-stop at a contest.
>
> I always charge my batteries in series so I charge 2 sets of batteries at 
> a
> time.  This requires the packs to be within 0.01V of each other before the
> charge, which they typically are.  With the new TP 10 cell balancer coming
> it will make series charging quite safe.
>
>>I know that several controllers impersonated in-flight smoke systems. That
>
> one I knew about and is to be expected when you put a lot of DC 
> electricity
>
> though things, sooner or later, right!
>
> I am running the Schulze 32.55K esc, thats 55A continuous, 73A burst
> rating.  400 flights on the same controller not a single problem, and it
> runs very cool (less than 100F).
>
> My only complaint with all the equipment I tried were the Apogee packs, 
> its
> not that the packs/cells were bad, but that I didnt realize how often and
> how long you sometimes run at full throttle with electrics especially in
> wind.  With this in mind now, I only recommend to people to run packs that
> can give them their peak static draw continuously.  By not doing this IMO
> you are pushing the batteries far too hard and they will fail on you.  The
> newer 15C packs are all pretty much capable of providing this kind of
> power, most of the 10C packs (last years stuff) were borderline.
>
> The trick to electrics is to cross your t's and dot your i's........move
> slowly and understand what is going on.  Get a good voltmeter (Fluke 81438
> is an excellent buy), IR Thermometer and a wattmeter.  Check things often
> intially until you are comfortable that everything is working as planned.
> Its not like glow where if you prop wrong you land and change it.....the
> wrong prop can destroy your motor, controller, packs!  The electric setups
> need a bit of engineering and planning to work right, and once you get it
> they work great!
>
> See you in Muncie next year!
>
> Chad Northeast, P.Eng.
> Design Engineer
> Coiled Tubing Research and Engineering
> BJ Services Canada
> (403) 531-5183
>
>
>
> Del,
>
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> 

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