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Old Feb 12, 2013, 01:10 PM
60 years of RC flying
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Originally Posted by Stigern View Post

Btw, what is a safe value for voltage alarm? 9,5volts?
That's a LiPo you're talking about, so 9.5v is much too low. I'd use about 11v to ensure that I have at least 10% capacity left.
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Old Feb 13, 2013, 07:49 AM
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I use 10.2V it is 3.4 V for 1 article. This is more than enough!
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Old Feb 13, 2013, 12:38 PM
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Originally Posted by juraj.jurej View Post
I use 10.2V it is 3.4 V for 1 article. This is more than enough!
That's much too low if you want some reserve. It's also bad for the battery.

By the time a 3s LiPo gets down to 10.5 volts (resting voltage), it's essentially exhausted.

Remember that this application is quite different from using the battery to drive a motor. In that case LVC would be set at 3.2v/cell or so but that's under full load, which may be 20A and can depress the voltage by as 1v or more. For transmitter applications, the current draw is typically 200mA and the voltage depression is minor. So if you take the battery down below 11v you are into dangerous territory.
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Old Feb 13, 2013, 12:42 PM
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I see. So UNLOADED low voltage should be set higher than LOADED low voltage. Makes perfect sense.
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Old Feb 13, 2013, 01:45 PM
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11.1 V battery voltage is constant. Neither voltage measurements Rx is not as accurate to 0.1 V. Set the alarm to 11V is definitely too much. Battery remains at 50% charged. Each battery has LIMITATIONS number of charge cycles. Nema is vibijať below 3V per cell. 3.4 V is quite safe even if it is a Tx battery. This is my opinion. I set to 10.2 V
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Old Feb 13, 2013, 01:51 PM
kha
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Quote:
Originally Posted by juraj.jurej View Post
11.1 V battery voltage is constant. Neither voltage measur....
The best way is to adjust it with charger that shows how much was pushed in.

Set alarm on tx to 11v and use the tx as normal until alarm. Charge and compare the pushed capacity to the battery nominal capacity and if less than 80% was loaded decrease the voltage a bit and see again after next alarm.

You want to target that 80% mark.
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Old Feb 13, 2013, 03:40 PM
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I then reached around 10.2 V at about 75% discharge capacity. But I think it is an individual type of battery.
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Old Feb 13, 2013, 07:52 PM
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Canada, ON, Ottawa
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Quote:
Originally Posted by juraj.jurej View Post
11.1 V battery voltage is constant. Neither voltage measurements Rx is not as accurate to 0.1 V. Set the alarm to 11V is definitely too much. Battery remains at 50% charged. Each battery has LIMITATIONS number of charge cycles. Nema is vibijať below 3V per cell. 3.4 V is quite safe even if it is a Tx battery. This is my opinion. I set to 10.2 V
At 11.0 volts for a 3s battery under low discharge (<0.5C) you have about 10% charge left. That's a pretty good level at which to get a warning. This is the situation in transmitter use.

If you are discharging at 10C, as you would likely be doing if the battery were driving a motor, then 10.2v might be a reasonable level for a warning, because you'd likely still have 10 or 20% charge left. But this is an entirely different situation from that in a transmitter. Under low discharge transmitter use, 10.2v corresponds to something like 1% of charge left.

By the way, don't take these numbers too exactly. There are lots of variables when discharging at high rates. The point is, though, that the broad principles and magnitudes apply.

The bottom line is very simple: for long life, don't take a LiPo down below 3.6v/cell (resting voltage). For transmitter use, 11.0v is a nice comfortable warning level for a 3s battery. There is absolutely no need to push the limits and get a few more minutes out of it at risk of getting to the zone where voltage drops very rapidly.

EDIT: One exception to the above would be a very old, very high internal resistance battery, which could hit 10.2v and still have lots of charge left, even at the low discharge rate of a transmitter. But such a battery should not be used, as it's in the process of failure.
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Old Feb 13, 2013, 07:54 PM
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Originally Posted by juraj.jurej View Post
I then reached around 10.2 V at about 75% discharge capacity. But I think it is an individual type of battery.
What was your rate of discharge?
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Old Feb 13, 2013, 10:05 PM
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I can discharge to 9V all day long and not harm anything, you guys need to get a LiFe (you know LiFe, not LiPo ) ahhh.......... yeah, i know.......... it was bad.

OK, now seriously, i am having issues with channel allocation, I'm racking my brain with what i need to do here and i'm sure its simple but cant for the life of me work out whats going on.

I have connected my 9XR to my ChainLink Tx and bound the Rx, I am running mode 2 so connected the esc to channel 3 and a servo to channel 1 (to imitate ailerons) , now when i hit the throttle (left stick) the aileron servo moves and when i push the elevator (right stick) up the motor spins up.

I have checked the mode setting and its def in mode 2 and i changed the channel order on one of the menu screens to AETR (standard is RETA i think) but that made no difference.

On the mixes screen the channel allocation is all mixed up, do i need to change it here?

I have 2 9X's and dont remember having this issue, or atleast i was able to work it out easily enough but this time i'm stumped.
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Old Feb 13, 2013, 10:27 PM
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Yes that is were you must change it in the mixes it should read (if you use AETR inputs to match your receiver)
channe l1 + or - 100% AIL
channel 2 + or - 100% ELE
channel 3 + or - 100% THR
channel 4 + or - 100% RUD
the + or - denotes servo direction that you can change in the mixes or in the limits menu.
If you are running the stock firmware there is a servo reversing menue.
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Last edited by helichoper; Feb 13, 2013 at 10:31 PM. Reason: more info
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Old Feb 13, 2013, 10:40 PM
Because gas is for BBQ's
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Originally Posted by helichoper View Post
Yes that is were you must change it in the mixes it should read (if you use AETR inputs to match your receiver)
channe l1 + or - 100% AIL
channel 2 + or - 100% ELE
channel 3 + or - 100% THR
channel 4 + or - 100% RUD
the + or - denotes servo direction that you can change in the mixes or in the limits menu.
If you are running the stock firmware there is a servo reversing menue.
Great, thanks helichoper. I figured that would probably be it, i tried changing them last night but was adding +'s and stuff everywhere and couldn't actually change the allocation. I will have to read up on the manual on how to change them.

Running stock firmware atm but have the programmer and figure it might be wise uploading open9X before i get too many models set up.
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Old Feb 13, 2013, 10:56 PM
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No problems --you just highlight it with the down button and press and hold menu button to get in to the edit screen and make changes there or just delete and do the proses above--I fully recommend updating to the latest er9x and epee or open 9x and companion x as the ability to do it all on the computer and test it on the sim and then flashing the radio is just the best.
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Old Feb 13, 2013, 11:36 PM
Because gas is for BBQ's
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Thanks again mate. I have er9x on one of my 9X's and while i dont use it anywhere near its potential it is good to have the options when needed.

Looks like i'll be flashing tonight.
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Old Feb 14, 2013, 01:13 AM
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You love it-- have a read here for info if you need it--
http://9xforums.com/wiki/index.php/F...t_1_-_Hardware
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