what receiver pack with digital servos?

[Paris]

Hi there.

I have a raptor60 with all digital servos, (S9252,S9253) and I'm really
confused with the battery consumption of these servos. i had a 1600 ni/cd
pack,which i thought it went bad and replaced it with a new one (1700 ni/cd)
..but after a 5 minute flight,and hovering in front of me the "battery
indicator" (a led-type checker from JP) shows "2-3 led's lower" which is
already 1/3 less from full,and after landing, the indicator shows full
again.moving the sticks after landing and the indicator is falling again
during the movement. this makes me a little nervous to fly it again.
on my planes with standard servos and 1100 mah batteries this happens after
a few hours of flight time.
is this normal? or do i have to check something?
what capacity would show the indicator "full" after an hour of flight time?
(suppose this is normal)

regards
Paris

[Fritz Blackburn]

The battery checker will not show how much volts / amps are left in the
battery. The LEDs indicate bus voltage at the current load. At hover with
digital servos the load can be anywhere from 1 to 2 amps. During 3d
instantaneous loads of up to 5 amps can happen. The battery voltage output
decreases as load increases. That's why in a hover with servos doing work the
voltage will be lower. After landing the servos are just sitting there and the
battery voltage creeps back up. You can find out how much power a flight
consumes by fully charging the battery, flying and the discharging the battery
via a digital cycler (aka Supernova250, Triton etc.)
For a wild guess, figure 2 amps draw on a 1700 mah battery = 30 minutes flight
time. So two hot and heavy 12 minute flights before recharge.

Michael 'Fritz' Blackburn
VP-94 Techrep NAS New Orleans
http://www.fritzthecat.info



Paris wrote:

> Hi there.
>
> I have a raptor60 with all digital servos, (S9252,S9253) and I'm really
> confused with the battery consumption of these servos. i had a 1600 ni/cd
> pack,which i thought it went bad and replaced it with a new one (1700 ni/cd)
> .but after a 5 minute flight,and hovering in front of me the "battery
> indicator" (a led-type checker from JP) shows "2-3 led's lower" which is
> already 1/3 less from full,and after landing, the indicator shows full
> again.moving the sticks after landing and the indicator is falling again
> during the movement. this makes me a little nervous to fly it again.
> on my planes with standard servos and 1100 mah batteries this happens after
> a few hours of flight time.
> is this normal? or do i have to check something?
> what capacity would show the indicator "full" after an hour of flight time?
> (suppose this is normal)
>
> regards
> Paris

--

[Fritz Blackburn]

Doh, math genius. 2 amps, 1700mah = about 45 minutes and 3 flights.


Fritz Blackburn wrote:

> The battery checker will not show how much volts / amps are left in the
> battery. The LEDs indicate bus voltage at the current load. At hover with
> digital servos the load can be anywhere from 1 to 2 amps. During 3d
> instantaneous loads of up to 5 amps can happen. The battery voltage output
> decreases as load increases. That's why in a hover with servos doing work the
> voltage will be lower. After landing the servos are just sitting there and the
> battery voltage creeps back up. You can find out how much power a flight
> consumes by fully charging the battery, flying and the discharging the battery
> via a digital cycler (aka Supernova250, Triton etc.)
> For a wild guess, figure 2 amps draw on a 1700 mah battery = 30 minutes flight
> time. So two hot and heavy 12 minute flights before recharge.
>
> Michael 'Fritz' Blackburn
> VP-94 Techrep NAS New Orleans
> http://www.fritzthecat.info

[Tim van Halteren]

As Fritz Blackburn already mentioned the voltage output decreases under
load. This is due to the internal resistance of the battery. It is my
experience that the 1700 Sanyo cells (are yours Sanyo?) have a large
internal resistance. Don't sweat it, just do as suggested and measure the
capacity left after flight with a decent (dis)charger.

Tim


"Fritz Blackburn" <techrep@bellsouth.net> wrote in message
news:3EC04E01.862F933F@bellsouth.net...
> The battery checker will not show how much volts / amps are left in the
> battery. The LEDs indicate bus voltage at the current load. At hover
with
> digital servos the load can be anywhere from 1 to 2 amps. During 3d
> instantaneous loads of up to 5 amps can happen. The battery voltage
output
> decreases as load increases. That's why in a hover with servos doing work
the
> voltage will be lower. After landing the servos are just sitting there
and the
> battery voltage creeps back up. You can find out how much power a flight
> consumes by fully charging the battery, flying and the discharging the
battery
> via a digital cycler (aka Supernova250, Triton etc.)
> For a wild guess, figure 2 amps draw on a 1700 mah battery = 30 minutes
flight
> time. So two hot and heavy 12 minute flights before recharge.
>
> Michael 'Fritz' Blackburn
> VP-94 Techrep NAS New Orleans
> http://www.fritzthecat.info
>
>
>
> Paris wrote:
>
> > Hi there.
> >
> > I have a raptor60 with all digital servos, (S9252,S9253) and I'm really
> > confused with the battery consumption of these servos. i had a 1600
ni/cd
> > pack,which i thought it went bad and replaced it with a new one (1700
ni/cd)
> > .but after a 5 minute flight,and hovering in front of me the "battery
> > indicator" (a led-type checker from JP) shows "2-3 led's lower" which is
> > already 1/3 less from full,and after landing, the indicator shows full
> > again.moving the sticks after landing and the indicator is falling again
> > during the movement. this makes me a little nervous to fly it again.
> > on my planes with standard servos and 1100 mah batteries this happens
after
> > a few hours of flight time.
> > is this normal? or do i have to check something?
> > what capacity would show the indicator "full" after an hour of flight
time?
> > (suppose this is normal)
> >
> > regards
> > Paris
>
> --
>
>

[Paris]

Thanks guys, I'll discharge them on the cycler and measure the capacity.
my cells are Sanyo N-1700SCR.
too bad i couldn't find bigger ones.only KR-2300SCE ,but these shouldn't be
charged as fast as the N-type.

regards
Paris


"Tim van Halteren" <t_dot_van_dot_halteren@inter.nl.net> wrote in message
news:3ec0a775$0$1126$4d4ebb8e@news.nl.uu.net...
> As Fritz Blackburn already mentioned the voltage output decreases under
> load. This is due to the internal resistance of the battery. It is my
> experience that the 1700 Sanyo cells (are yours Sanyo?) have a large
> internal resistance. Don't sweat it, just do as suggested and measure the
> capacity left after flight with a decent (dis)charger.
>
> Tim
>
>
> "Fritz Blackburn" <techrep@bellsouth.net> wrote in message
> news:3EC04E01.862F933F@bellsouth.net...
> > The battery checker will not show how much volts / amps are left in the
> > battery. The LEDs indicate bus voltage at the current load. At hover
> with
> > digital servos the load can be anywhere from 1 to 2 amps. During 3d
> > instantaneous loads of up to 5 amps can happen. The battery voltage
> output
> > decreases as load increases. That's why in a hover with servos doing
work
> the
> > voltage will be lower. After landing the servos are just sitting there
> and the
> > battery voltage creeps back up. You can find out how much power a
flight
> > consumes by fully charging the battery, flying and the discharging the
> battery
> > via a digital cycler (aka Supernova250, Triton etc.)
> > For a wild guess, figure 2 amps draw on a 1700 mah battery = 30 minutes
> flight
> > time. So two hot and heavy 12 minute flights before recharge.
> >
> > Michael 'Fritz' Blackburn
> > VP-94 Techrep NAS New Orleans
> > http://www.fritzthecat.info
> >
> >
> >
> > Paris wrote:
> >
> > > Hi there.
> > >
> > > I have a raptor60 with all digital servos, (S9252,S9253) and I'm
really
> > > confused with the battery consumption of these servos. i had a 1600
> ni/cd
> > > pack,which i thought it went bad and replaced it with a new one (1700
> ni/cd)
> > > .but after a 5 minute flight,and hovering in front of me the "battery
> > > indicator" (a led-type checker from JP) shows "2-3 led's lower" which
is
> > > already 1/3 less from full,and after landing, the indicator shows full
> > > again.moving the sticks after landing and the indicator is falling
again
> > > during the movement. this makes me a little nervous to fly it again.
> > > on my planes with standard servos and 1100 mah batteries this happens
> after
> > > a few hours of flight time.
> > > is this normal? or do i have to check something?
> > > what capacity would show the indicator "full" after an hour of flight
> time?
> > > (suppose this is normal)
> > >
> > > regards
> > > Paris
> >
> > --
> >
> >
>
>

[David Lodge]

My larger helis use about 400-500mAh max per 15 minutes flight so you
should get 3 may be 4 flights from your pack.

David.

"Paris" <par ap*o@hot*mail.c om> wrote in message news:<b9p80s$gg6$1@ulysses.noc.ntua.gr>...
> Hi there.
>
> I have a raptor60 with all digital servos, (S9252,S9253) and I'm really
> confused with the battery consumption of these servos. i had a 1600 ni/cd
> pack,which i thought it went bad and replaced it with a new one (1700 ni/cd)
> .but after a 5 minute flight,and hovering in front of me the "battery
> indicator" (a led-type checker from JP) shows "2-3 led's lower" which is
> already 1/3 less from full,and after landing, the indicator shows full
> again.moving the sticks after landing and the indicator is falling again
> during the movement. this makes me a little nervous to fly it again.
> on my planes with standard servos and 1100 mah batteries this happens after
> a few hours of flight time.
> is this normal? or do i have to check something?
> what capacity would show the indicator "full" after an hour of flight time?
> (suppose this is normal)
>
> regards
> Paris