[NSRCA-discussion] E-power

Wed Apr 18 12:16:59 AKDT 2007

I'm sure most of us are familiar with the VoltWatch battery monitor. It uses
a simple LM3914 integrated circuit from National Semiconductor. A nice
visual indicator just before takeoff. Seems to me that it could be easily
modified, or even re-designed, for the higher voltage packs the E-power guys
are using. Any of you EEs want to make a few bucks?

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Keith Black
Sent: Wednesday, April 18, 2007 2:29 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] E-power

I've used a method similar to the colored bands. The problem is, as Rex
mentioned, sometimes you forget to remove the green indicator when you use
the battery. To solve that problem why not use some type of plug cover that
must be removed in order to use the battery. This will prevent accidentally
leaving the green indicator on a pack. 

Rules:

1. Never use a battery that doesn't have a plug cover unless you first
testing the voltage.

2. Put plug covers on as you remove the battery from the charger.  

3. If you forget to put the plug cover on after charging, ALWAYS check
voltage before putting it on or using it. 

Keith

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

From: Rex LESHER <mailto:trexlesh at msn.com>  

To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  

Sent: Tuesday, April 17, 2007 11:02 PM

Subject: Re: [NSRCA-discussion] E-power

Been there, done that...  Most of us have, and won't admit it.. lol

I finally got two colors of bands to place around the packs...  Green and
Red.  When I get done charging, I place a Green

band on the battery.  After I fly, I place a Red band around the pack...  I
was thinking about how clever I was...  Right up

until I flew a pack the other day that didn't seem to have much power.  It
had a Green band on it!!!  Green means go, right?

Some dumby got lazy and didn't follow procedure....   New Rule!!!   "ALWAYS
CHECK VOLTAGE BEFORE FLIGHT, NO MATTER WHAT."

I still use the color bands, but now the voltage gets checked anyway!  With
multiple packs, it's easy to get confused  which pack is

which.  Especially when you are preheating the packs in cold weather!  I got
out of the habit of checking the pack voltage because I'm using

the TP1010 charger, which displays voltage...   Bad habit, if you're not
taking it off the charger and putting it in the plane.

Just for you Don, MINE DEFINITELY TOOK MORE THAN 5200+.  All I will say is
that the 5300's have more than 5300!

I'm just wondering which pack you did that to?  lmao

Rex

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

From: AtwoodDon at aol.com 

To: nsrca-discussion at lists.nsrca.org 

Sent: Tuesday, April 17, 2007 8:40 PM

Subject: Re: [NSRCA-discussion] E-power

One thing I have begun doing is checking pack voltage before I fly,
verifying full charge condition. 

Having multiple battery sets, I may have gotten confused once (I will deny
it in public tho) and took off with a partially discharged pack, couldn't
figure out why I lost power and had to land about half way thru a
flight.......  Whoops....  If I had actually done that, I guesstimate I
would have put back about 5200+ mah into a TP5300, not that I would have
actually done that ever    <http://cdn-cf.aol.com/se/smi/0201d20638/02> 

Good news is, the pack seems fine, has over 70 cycles on it now and still
going strong (when I charge it)

Don

In a message dated 4/17/2007 8:31:21 P.M. Pacific Daylight Time,
robcase1 at cox.net writes:

Thanks for all the inputs.  The second pac only took 2500 Mah, so may'be the

batteries just need more time to be formed.  I will continue to make short 
4 - 5 minute flight for the next 6 flights to hopefully form the cells 
better.  I feel better about it tonight after putting back 2300 and 2500 
respectively, back into each pack :)
----- Original Message ----- 
From: "Steven Maxwell" <patternrules at earthlink.net>
To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
Sent: Tuesday, April 17, 2007 9:11 PM
Subject: Re: [NSRCA-discussion] E-power

> Do 5 or 6 short flights to form the new batteries.  Don't get me wrong
> here but for just starting out your pushing the limits but your last post
> looks fine 3000's should be good. By pushing I mean for an E newbie, not
> like I have this figured out, my wrost enemy is flying to far out I got 
> out
> to 225 or more with a wind to my back and put back in 2579 MAh
> One of the big things I found with the 5330/F3A is it's real easy to use
> more amps than you need, what I found was after a point there is no more
> power just higher amps not sure why other than maybe the AXI is like a
> torque curve, for lack of a better term, maybe the AXI peaks at say 68 
> amps
> maybe less maybe more, but the thing is if your running more than that,
> whatever that number is you just pushing more amps.
>
> Steven Maxwell
>
>
>
>
>> [Original Message]
>> From: Robert & Casey Green <robcase1 at cox.net>
>> To: NSRCA Mailing List <nsrca-discussion at lists.nsrca.org>
>> Date: 4/17/2007 10:27:49 PM
>> Subject: Re: [NSRCA-discussion] E-power
>>
>> How many flights, should you put a new pack through to break them in?  I
>> charged the first pack that I flew tonight and put back 2300 Mah, the
> second
>> pack looks like it will take 3000 to be replenished, which is about the
> 80%
>> of the pack.  After putting that much back in the pack earlier I am going
> to
>> have to throw these packs away as no good, or do I keep flying them and
> see
>> what happens?
>> Thanks for your responses so far.  I think that I may have enough room
> 10S
>> 5000 extreme.  I am about three ounces over, sure I can find a way to
> make
>> it work for the NATS.
>> ----- Original Message ----- 
>> From: "Duane Beck" <duane.e.beck at comcast.net>
>> To: "NSRCA Mailing List" <nsrca-discussion at lists.nsrca.org>
>> Sent: Tuesday, April 17, 2007 8:06 PM
>> Subject: Re: [NSRCA-discussion] E-power
>>
>>
>> > Robert & Casey Green wrote:
>> >> Don I was pulling 72 Amps, on a 20x13 prop.
>> >
>> > Is that peak static, or unloaded in the air?  I assume those are 20C
>> > packs.
>> > _______________________________________________
>> > NSRCA-discussion mailing list
>> > NSRCA-discussion at lists.nsrca.org
>> > http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
>> >
>>
>>
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