Single LiFe Battery to Run the Ingition and Plane
04-17-2012, 12:56 PM
#26
RE: Single LiFe Battery to Run the Ingition and Plane
8 tracks, 27mhz systems, and ignition noise go together like a horse and a cart.
I've been running a number of 50 and 85cc planes with a single A123 from WrongWay with multiple leads as described above to the receiver and ignition for hundreds of flights with no issues flying JR/Spektrum DSM2 and DSMX
I've been running a number of 50 and 85cc planes with a single A123 from WrongWay with multiple leads as described above to the receiver and ignition for hundreds of flights with no issues flying JR/Spektrum DSM2 and DSMX
04-17-2012, 01:32 PM
#27
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RE: Single LiFe Battery to Run the Ingition and Plane
ORIGINAL: BarracudaHockey
8 tracks, 27mhz systems, and ignition noise go together like a horse and a cart.
I've been running a number of 50 and 85cc planes with a single A123 from WrongWay with multiple leads as described above to the receiver and ignition for hundreds of flights with no issues flying JR/Spektrum DSM2 and DSMX
8 tracks, 27mhz systems, and ignition noise go together like a horse and a cart.
I've been running a number of 50 and 85cc planes with a single A123 from WrongWay with multiple leads as described above to the receiver and ignition for hundreds of flights with no issues flying JR/Spektrum DSM2 and DSMX
04-17-2012, 11:03 PM
#28
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RE: Single LiFe Battery to Run the Ingition and Plane
ORIGINAL: SpinnerRow
A 2200uf cap will take about 22 milliseconds (or 0.022 seconds) to fully charge if the resistance on the battery is about 10 ohms (and LiFe batteries are very low resistance). Consequently, the engine may fire one more time after the switch is turned off and will not be something that I will notice (and don't notice as I have three planes with this circuit).
Also I have a P-51 with a DLE 20 that runs wide open from the time it leaves the ground until I'm ready to land it. On a 10 minute flight, it draws 180mah for the ignition and plane. I have a 2300mah battery in it and I could fly it 7-8 times with no worries. Plus a fully charged battery is only 10 minutes away.
ORIGINAL: OliverJacob
This setup might actually be working fine. The capacitor helps to get a constant current flow from the battery.
Only thing what could cause a problem is the moment you turn on the switch - the discharged capacitor will have a very low resistance and draw a high current until charged. This may not be a problem at all, just something to think about and the bigger the capacity the bigger the draw. This happens only for a split second and could fry your diode in the worst case.
Another thing - your power switch will not instantly kill your engine anymore. It dies after the capacitor is discharged, which can take some time.
This setup works if you have an optical kill switch. People who don't use them and kill the engine via throttle should be aware of the fact that the ignition stays 'hot' for some time after they turned the power switch off.
With the double pole switch and the optical kill switch you would not have that problem. Just be aware of the capacitor acting as a small battery.
This setup might actually be working fine. The capacitor helps to get a constant current flow from the battery.
Only thing what could cause a problem is the moment you turn on the switch - the discharged capacitor will have a very low resistance and draw a high current until charged. This may not be a problem at all, just something to think about and the bigger the capacity the bigger the draw. This happens only for a split second and could fry your diode in the worst case.
Another thing - your power switch will not instantly kill your engine anymore. It dies after the capacitor is discharged, which can take some time.
This setup works if you have an optical kill switch. People who don't use them and kill the engine via throttle should be aware of the fact that the ignition stays 'hot' for some time after they turned the power switch off.
With the double pole switch and the optical kill switch you would not have that problem. Just be aware of the capacitor acting as a small battery.
Also I have a P-51 with a DLE 20 that runs wide open from the time it leaves the ground until I'm ready to land it. On a 10 minute flight, it draws 180mah for the ignition and plane. I have a 2300mah battery in it and I could fly it 7-8 times with no worries. Plus a fully charged battery is only 10 minutes away.
Correct. I experience similar with the 2500mA.hr LiFe I am using. I don;t have a capacitor in the circuit though, just the diode. I'm flying FASST and never had an issue.
Different folk have different levels of comfort but at the end of the day we each should do a bit of science and come to our conclusions.
I concluded from a bit of maths and science that running a single battery present no more risk than running two battery's. If one battery fails then everything dies.
With a two battery set up, if the Rx battery fails and theres no fail save or opto kill the engine keeps running with no control.
At the end of the day, you have to come up a with a system that works for you as the pilot, but still remains respectfully safe to the other flyers at your club. I see no issues with a single battery if the safety measure provide by the radio manufacturer and ancillary devices are used and implemented correctly
04-18-2012, 07:45 AM
#29
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RE: Single LiFe Battery to Run the Ingition and Plane
ORIGINAL: TimBle
Correct. I experience similar with the 2500mA.hr LiFe I am using. I don;t have a capacitor in the circuit though, just the diode. I'm flying FASST and never had an issue.
Different folk have different levels of comfort but at the end of the day we each should do a bit of science and come to our conclusions.
I concluded from a bit of maths and science that running a single battery present no more risk than running two battery's. If one battery fails then everything dies.
With a two battery set up, if the Rx battery fails and theres no fail save or opto kill the engine keeps running with no control.
At the end of the day, you have to come up a with a system that works for you as the pilot, but still remains respectfully safe to the other flyers at your club. I see no issues with a single battery if the safety measure provide by the radio manufacturer and ancillary devices are used and implemented correctly
Correct. I experience similar with the 2500mA.hr LiFe I am using. I don;t have a capacitor in the circuit though, just the diode. I'm flying FASST and never had an issue.
Different folk have different levels of comfort but at the end of the day we each should do a bit of science and come to our conclusions.
I concluded from a bit of maths and science that running a single battery present no more risk than running two battery's. If one battery fails then everything dies.
With a two battery set up, if the Rx battery fails and theres no fail save or opto kill the engine keeps running with no control.
At the end of the day, you have to come up a with a system that works for you as the pilot, but still remains respectfully safe to the other flyers at your club. I see no issues with a single battery if the safety measure provide by the radio manufacturer and ancillary devices are used and implemented correctly
Single battery or 2, whatever, takes the 2 switch plan to make me comfortable. Opti switch is step one regarding any of these setups. IBEC's are great, but just an added expense if you can solder and have a grip on the diode(s) plan (or have wrongway's contact info?).
BTW, hope I'm not jinxing myself saying this, but my Hitec A9 has performed flawlessly through all this learning curve I've been on. It has yet to glitch as long as it's fed enough power. It WILL brown out on a single 4 or 5 cell NiMh especially at full power on knife edge! The beauty with this radio though, if you have enough air left under you when you recognize this, you can pull the power, right the plane, and it will recover like nothing ever happened VERY quickly!
