[Giant Scale Aerobatics] Fw: Parallel charging

[JOddino]

Thanks for responding.  I'd like to hear from anyone else who has
experienced this problem.  I'm amazed that we haven't seen more of these.
Regards, Jim
----- Original Message ----- 
From: "Jean-Yves Falardeau" <jyfalardeau at sympatico.ca>
To: <gsal at yahoogroups.com>; <discussion at nsrca.org>
Sent: Saturday, May 08, 2004 9:48 AM
Subject: Re: [Giant Scale Aerobatics] Fw: Parallel charging


> i have been experimenting the samething last year and the conclusion i
made
> was that ,as you mention, if the batteries are pluged in the receiver
while
> being charged will affect any peak charger for any type of batteries
because
> they have a common ground thrue the receiver busbar. this will for sure
> change the peak value and will cause the chargers( i use two charger) to
> quit at the wrong time and you will think that they are full charge and in
> reality they are not. i have had batterie pack that almost cought on fire
> because the charger would charge to a higher voltage than the batt would
> require also. this situation could be very dangerous if the airplane is
left
> without watching for a period of time.
> for conclusion i always disconnect at least one pack from the system and
> since i never had any problem.
> ----- Original Message ----- 
> From: "JOddino" <joddino at socal.rr.com>
> To: <gsal at yahoogroups.com>; <discussion at nsrca.org>
> Sent: Saturday, May 08, 2004 11:10 AM
> Subject: [Giant Scale Aerobatics] Fw: Parallel charging
>
>
> > A warning to all:
> > Here is a real potential problem.  We are talking about NiCd and NiMH
> charging.  Recently two guys have burned up packs in their planes. I get
> called because they think it was caused by my switch harnesses.  I got
> suspicious when I found out both were using parallel packs and switch
> harnesses.  I remember when Chip Hyde first started using the original
> Duralites in parallel he found he could not charge both at the same time
if
> they were both plugged into the receiver.  We found it was due to the
> sensing resistors in the return wires from the batteries being charged,
> being short circuited by the connection in the receiver.  This confuses
the
> charger.  I wasn't sure if the Schulze and the other sophisticated
chargers
> used low side current sensing so I asked.  I didn't get a perfectly clear
> answer but you can see the German approach.
> > If you don't know if your charger has this potential problem don't
charge
> simultaneously unless you unplug one from the receiver.
> > For those of you following the discussion of the NMP Li-Ion charger, it
> does not have low side current sensing, it has a meter in the high side,
and
> it is perfectly okay to charge in parallel simultaneously in the plane.
> > Jim
> > ----- Original Message ----- 
> > From: hotline at schulze-elektronik-gmbh.de
> > To: JOddino at socal.rr.com
> > Sent: Saturday, May 08, 2004 4:00 AM
> > Subject: Re: Parallel charging
> >
> >
> > you ALWAYS have to charge batteries directly and all alone connected to
> the charger.
> >
> >
> > Best regards
> > Matthias Schulze
> >
> > Schulze Elektronik GmbH
> > Prenzlauer Weg 6
> > 64331 Weiterstadt
> > Germany
> >
> > Fon: +49-6150-1306-5   (sales + answering machine)
> > Fon: +49-6150-1306-98 (hotline daily 14:00-16:00 local time CET)
> > Fax: +49-6150-1306-99
> >
> > eMail: sales at schulze-elektronik-gmbh.com for your order(s)
> > eMail: hotline at schulze-elektronik-gmbh.com for technical support
> > Homepage: http://www.schulze-elektronik-gmbh.com
> >
> >
> >         Original Message        processed by Tobit InfoCenter
> >         Subject:  Parallel charging (07-Mai-2004 4:24)
> >         From:     JOddino at socal.rr.com
> >         To:       hotline at schulze-elektronik-gmbh.com
> >
> >
> >   Is it possible that the charger gets confused if two batteries are
being
> charged simultaneously with two chargers and the batteries being charged
> have their returns connected as they are when they are plugged into a
single
> receiver through typical R/C switches?
> >
> >   Is there some type of current sensing in the return line that would
not
> function properly with two in parallel?
> >
> >   Thanks in advance.
> >   Jim Oddino
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
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