Turnigy 9x Tx LiPo battery conversion help
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Turnigy 9x Tx LiPo battery conversion help
Hi all,
I recently purchased a Turnigy 9x tranmitter and im considering converting to a LiPo battery pack instead of the stock 8xAA battery holder.
The transmitter: [link=http://www.hobbycity.com/hobbycity/s...idProduct=8991]http://www.hobbycity.com/hobbycity/s...idProduct=8991[/link]
Is it as simple as matching the battery voltage?
i.e. stock is 8xAA batteries, 8*1.5 = 12volts?
In this case it would correspond to a 3S LiPo.
Could someone with expertise confirm this logic and enlighten me on any other precautions before testing?
Thanks in advace.
Derku.
On a side note, anyone considered the RCmodelReviews LiPo hack on this tranmistter? He claims it is able to operate from 2S Lipo.
[link=http://www.rcmodelreviews.com/tendollarbattery.shtml]http://www.rcmodelreviews.com/tendollarbattery.shtml [/link]
I recently purchased a Turnigy 9x tranmitter and im considering converting to a LiPo battery pack instead of the stock 8xAA battery holder.
The transmitter: [link=http://www.hobbycity.com/hobbycity/s...idProduct=8991]http://www.hobbycity.com/hobbycity/s...idProduct=8991[/link]
Is it as simple as matching the battery voltage?
i.e. stock is 8xAA batteries, 8*1.5 = 12volts?
In this case it would correspond to a 3S LiPo.
Could someone with expertise confirm this logic and enlighten me on any other precautions before testing?
Thanks in advace.
Derku.
On a side note, anyone considered the RCmodelReviews LiPo hack on this tranmistter? He claims it is able to operate from 2S Lipo.
[link=http://www.rcmodelreviews.com/tendollarbattery.shtml]http://www.rcmodelreviews.com/tendollarbattery.shtml [/link]
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RE: Turnigy 9x Tx LiPo battery conversion help
I've heard of many guys converting their 8-cell, 12V radios over to 3S LiPos. Some just wire the pack straight in, others put one or two diodes in series with the pack to drop the voltage down a little. Since most NiCd or NiMH 8-cell packs will charge up to 11.5-12V, and the LiPo pack will charge up to 12.6V, the LiPo pack is a little higher voltage than the radio expects. To be safe, wiring a diode in series with the LiPo will drop the 12.6V down to around 11.6-11.9V. This will ensure you don't damage your radio with a higher voltage, and it will ensure that if you plug the standard wall-wart charger into the TX charge jack, the diode will block it and you won't destroy your LiPo pack and TX!
I am thinking of converting my Futaba 9C and Spektrum DX7 over to LiPo, and I'd definitely put a diode in series with them.
I am thinking of converting my Futaba 9C and Spektrum DX7 over to LiPo, and I'd definitely put a diode in series with them.
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RE: Turnigy 9x Tx LiPo battery conversion help
So far no issues with running 3S packs in TXs. Futaba's are okay (NOT 14MZ please!) and so are the JRs. My friends on the JR 9X are all enjoying the lipos and so am I, I finally did it after all these months. A 3S 1,500 mAh pack can last me over a month.
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RE: Turnigy 9x Tx LiPo battery conversion help
If you read the reviews for the TX LiPos on the HobbyCity website, it sounds like they just use a 1A micro diode from Radio Shack, a 1N4001:
http://www.radioshack.com/product/in...ductId=2036268
I'd just clip out a small section of the positive lead between the connector and the battery, clip the diode leads short, solder it inline, and put heat shrink tubing over the whole diode and solder joints. The diode will only work one way, so you can test it out before you solder it in. The silver band should go on the connector side of the wire, not the battery side of the wire, so it's forward biassed. Then you can only charge through the other two connectors (it has three connectors), but you're best off using the balancing connector to charge it anyway.
You should test fit the battery in the radio before adding the inline diode, to see where you can add it and still be able to plug the connector in, and get it to fit inside the battery compartment.
http://www.radioshack.com/product/in...ductId=2036268
I'd just clip out a small section of the positive lead between the connector and the battery, clip the diode leads short, solder it inline, and put heat shrink tubing over the whole diode and solder joints. The diode will only work one way, so you can test it out before you solder it in. The silver band should go on the connector side of the wire, not the battery side of the wire, so it's forward biassed. Then you can only charge through the other two connectors (it has three connectors), but you're best off using the balancing connector to charge it anyway.
You should test fit the battery in the radio before adding the inline diode, to see where you can add it and still be able to plug the connector in, and get it to fit inside the battery compartment.
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RE: Turnigy 9x Tx LiPo battery conversion help
ORIGINAL: -pkh-
If you read the reviews for the TX LiPos on the HobbyCity website, it sounds like they just use a 1A micro diode from Radio Shack, a 1N4001:
http://www.radioshack.com/product/in...ductId=2036268
I'd just clip out a small section of the positive lead between the connector and the battery, clip the diode leads short, solder it inline, and put heat shrink tubing over the whole diode and solder joints. The diode will only work one way, so you can test it out before you solder it in. The silver band should go on the connector side of the wire, not the battery side of the wire, so it's forward biassed. Then you can only charge through the other two connectors (it has three connectors), but you're best off using the balancing connector to charge it anyway.
You should test fit the battery in the radio before adding the inline diode, to see where you can add it and still be able to plug the connector in, and get it to fit inside the battery compartment.
If you read the reviews for the TX LiPos on the HobbyCity website, it sounds like they just use a 1A micro diode from Radio Shack, a 1N4001:
http://www.radioshack.com/product/in...ductId=2036268
I'd just clip out a small section of the positive lead between the connector and the battery, clip the diode leads short, solder it inline, and put heat shrink tubing over the whole diode and solder joints. The diode will only work one way, so you can test it out before you solder it in. The silver band should go on the connector side of the wire, not the battery side of the wire, so it's forward biassed. Then you can only charge through the other two connectors (it has three connectors), but you're best off using the balancing connector to charge it anyway.
You should test fit the battery in the radio before adding the inline diode, to see where you can add it and still be able to plug the connector in, and get it to fit inside the battery compartment.
-pkh-, this is the useful type of information I was looking for and I appreciate people like you(and the others who replied) for actively sharing their wealth of knowledge.
I would just like to ask what the voltage reading(or expected range) of the 3S LiPo would be after installing the diode? Dont want to damage my first and only Tx.
Again, thank you in advance.
Derku
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RE: Turnigy 9x Tx LiPo battery conversion help
No problem, always glad to help out.
The diode should give you a 0.6V - 1V voltage drop, depending on the current through the diode, so I believe you should see about 12V (12.6-0.6) with a standard (high impedance) voltmeter, and the loaded voltage with the radio on should be less than that, probably about 11.6-11.8V.
If you want to know the details:
Below is an I-V curve showing the voltage drop across the 1N4001 diode for various currents through it. To estimate what current your radio draws, divide your batt pack capacity by the number of hours of continuous use before it needs to be recharged. If you have a 2000mAh pack and you can leave it on for 4 hours straight before recharging, then your radio draws about 2000mAh/4h = 500mA. Looking at the curve below, the diode has a ~0.95V drop with 500mA of current through it, so you'd expect to see about 11.65V after the diode with a fresh 12.6V LiPo pack while your radio is on.
My NiMH TX packs typically peak out at 11.8 - 12V, so I figure my radios should be safe with anything less than 12V. This also means that when the 9.4V low battery alarm goes of, your LiPo will be at ~ 10.4V, and you'll have plenty of margin from the min 9V pack voltage.
The diode should give you a 0.6V - 1V voltage drop, depending on the current through the diode, so I believe you should see about 12V (12.6-0.6) with a standard (high impedance) voltmeter, and the loaded voltage with the radio on should be less than that, probably about 11.6-11.8V.
If you want to know the details:
Below is an I-V curve showing the voltage drop across the 1N4001 diode for various currents through it. To estimate what current your radio draws, divide your batt pack capacity by the number of hours of continuous use before it needs to be recharged. If you have a 2000mAh pack and you can leave it on for 4 hours straight before recharging, then your radio draws about 2000mAh/4h = 500mA. Looking at the curve below, the diode has a ~0.95V drop with 500mA of current through it, so you'd expect to see about 11.65V after the diode with a fresh 12.6V LiPo pack while your radio is on.
My NiMH TX packs typically peak out at 11.8 - 12V, so I figure my radios should be safe with anything less than 12V. This also means that when the 9.4V low battery alarm goes of, your LiPo will be at ~ 10.4V, and you'll have plenty of margin from the min 9V pack voltage.
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RE: Turnigy 9x Tx LiPo battery conversion help
The TX only uses 5-6v max. Everything over that is simply turned into heat inside the TX via the internal voltage regulator. A better solution would be to get two 3.7v batteries - like the "smart"2700mahr trustfires - wire them in series and then put a real voltage regulator IC (about $1.50) to drop the 7.4v down to 6v before it enters your TX. This can be soldered in line and heat shrinked for insulation. Batteries should last you about two days of constant on before needing recharge. Added advantage is that the Trustfires have built in protection circuitry which prevents over charging or over dis-charging so you don't have to worry about them like LIPO's.