[NSRCA-discussion] Main battery redundant lead for receiver

Tue Jan 24 07:54:33 AKST 2012

Scott,

   I depends on which Keith you ask. . . Good Keith, or Bad Keith. . . .

Keith Hoard
Collierville, TN
khoard at gmail.com

On Tue, Jan 24, 2012 at 10:51 AM, Scott McHarg <scmcharg at gmail.com> wrote:

> Wayne,
>   I redundant lipo (350mah) and a regulator will weigh in the neighborhood
> of 50-60g which is exactly why some of us (excluding Keith Hoard) are
> excited about Chris' new cable which eliminates the weight of the extra
> battery.
>
> Scott
>
>
> On Tue, Jan 24, 2012 at 11:48 AM, Wayne Galligan <wcgalligan at att.net>wrote:
>
>>   How much does a redundant LiPo and regulator weight?
>> I guess I have been away from this stuff too long... these electrons are
>> heavy things.
>>
>> Wayne Galligan
>>
>>  *From:* Anthony Romano <anthonyr105 at hotmail.com>
>> *Sent:* Tuesday, January 24, 2012 10:38 AM
>> *To:* nsrca-discussion at lists.nsrca.org
>> *Subject:* Re: [NSRCA-discussion] Main battery redundant lead for
>> receiver
>>
>>  Because an 1100mah A123 is 39g for the cell alone!
>>
>> Anthony
>>
>>  ------------------------------
>> From: wcgalligan at att.net
>> To: nsrca-discussion at lists.nsrca.org
>> Date: Tue, 24 Jan 2012 11:30:08 -0600
>>
>> Subject: Re: [NSRCA-discussion] Main battery redundant lead for receiver
>>
>>  After all this discussion about extra wire connectors and regulators,
>> etc., etc.   Interesting as it seems.
>> Why not use an 1100 mil A123 pack for the receiver without the regulator.
>> *  *I haven't weighed the difference but it couldn’t be that much.
>> Sounds like your going for a lot extra work to save a few “Grams”.
>>
>> Simplicity rules.
>>
>> Wayne Galligan
>>
>>  *From:* Keith Hoard <khoard at gmail.com>
>> *Sent:* Tuesday, January 24, 2012 10:01 AM
>> *To:* General pattern discussion <nsrca-discussion at lists.nsrca.org>
>> *Subject:* Re: [NSRCA-discussion] Main battery redundant lead for
>> receiver
>>
>> Anthony,
>>
>>    On a typical flight, I'm guessing the radio only uses around
>> 100-150Mah of power, while the motor is using 4000Mah, so that's about 4%
>> more draw on those two cells.  In practice, I haven't been able to see any
>> difference in the radio cells when I hook them up to my charger at the end
>> of a flight.  Sometimes cells #1 & #2 are the high cells after a flight, so
>> I think the power draw of the radio is negligible to our motor packs.
>>
>> The problem with two regulators plugged into the same 10S (or 5S) pack is
>> that you are creating a dead short between the cells thru the ground wires
>> (typically a straight wire thru the regulator).
>>
>> Say you plug Regulator #1 into cells #1&2, and Regulator #2 into cells
>> #6&7.  The regulator's *ground *wires now have 5 cells of voltage
>> potential (5 X 4.2V = 21Volts) between them since they are plugged into
>> cells # 1 and #6.  When those two ground wires are then plugged into your
>> receiver either thru a switch or direct connection the magic smoke will
>> escape and your retailer will rejoice.
>>
>> Also, if you have both of your regulators plugged into your motor pack
>> and the packs eject like Goose in Top Gun, you've lost both of your
>> redundant power sources.  However, if you use a tiny 2S LiPo that is
>> physically separated and secured inside your plane, you have both
>> electrical and physical redundancy.
>>
>> Hmmm, just thought of something . . . maybe we should tie down the
>> receiver so the main regulator can't take the receiver out with it. . . so
>> many contingencies, so little weight . . .
>>
>> Keith Hoard
>> Collierville, TN
>> khoard at gmail.com
>>
>>
>>
>>
>> On Tue, Jan 24, 2012 at 8:15 AM, Anthony Romano <anthonyr105 at hotmail.com>wrote:
>>
>>  Seems like a great idea but I have two questions. Do the packs come
>> down out of balance since two cells are serving extra load? Is there a
>> problem with parallel operation of two regulators?
>>
>> Thanks,
>>
>> Anthony
>>
>>  ------------------------------
>> From: joddino at socal.rr.com
>> Date: Mon, 23 Jan 2012 15:25:00 -0800
>> To: nsrca-discussion at lists.nsrca.org
>> Subject: Re: [NSRCA-discussion] Main battery redundant lead for receiver
>>
>> I've been using this setup for sometime and it is working great.  I have
>> my two cell LiPo charged to 7.5 volts and it is connected to a 6.0 volt
>> regulator into the receiver.  The cable connected to the balance connector
>> on the "bottom" 5S is connected to a 6.3 volt regulator so it supplies all
>> the current to the system and the 2S pack never needs charging.  I'm using
>> an 800 mAh pack but it could be even smaller.
>>
>> Jim O
>>
>>
>>  On Jan 23, 2012, at 2:09 PM, Scott McHarg wrote:
>>
>> Guys,
>>    Chris Moon just e-mailed me about some leads that were done at the
>> factory.  These leads run off your balance leads to a voltage regulator and
>> allow your main battery pack to be utilized as a redundant receiver
>> battery.  It is NOT meant to be a primary but it will save 20+ grams if
>> you're running 2 rx batteries.  You still have to run the 2nd regulator for
>> true redundancy but you eliminate the 2nd battery.  These leads are factory
>> made and eliminate the need to make them yourself with the concern about
>> plugging in to the wrong cell.  I know in my article, I was pretty much
>> against doing this as a backup but, with Chris having this made at the
>> factory, he has all but eliminated making a mistake by tying to the wrong
>> cell.  I have the link that I'll e-mail you off-list or you can just go to
>> his website.  I don't want to break the NSRCA list rules by advertising for
>> him even though he advertises with the NSRCA.  The leads are only $3.99
>> each and are found under the Connectors/Adapters listing.
>>
>> Thank,
>> Scott
>>
>> --
>> *Scott A. McHarg*
>>
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>
>
>
> --
> *Scott A. McHarg*
>
>
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