Transmitter Voltage
01-13-2010, 10:34 AM
#1
Transmitter Voltage
I have an 8103 and a 9303 (both still on fixed frequency). Last spring i installed a 2300mah 3s lipo in each transmitter. That has worked out great for me. What i have been doing is charging the batteries to full charge and then discharging to bring them down to ~11.8v before installing them back in to the transmitters. My question is; is that really necessary? How much voltage with these transmitters take before there is any risk of damage?
01-13-2010, 11:20 AM
#2
My Feedback: (2)
RE: Transmitter Voltage
I have been using 2cell LiPos 2500mah in my 8103 and 9303 for a couple of years without incident. I charge them up to 12.6 and they last for weeks. It only takes a hour to recharge fully.
There are some threads that quote the use of a particular Diode that will drop the voltage of the LiPo pack to the level of an NiMh. You can get this part at Radio Shack.
While many Battery manufacturers have told me that using LiPo Tx batteries is safe, JR specifically advises against it as there have been some instances where a component in the Tx has failed due to the higher voltage. Whether or not they could change components within the Tx to support LiPo Tx batteries is another story. One thread told me the exact component and the replacement part to get, but I would have to look that up.
I fly two or three flights per day and it is only during the first week where the voltage is above 12v. It has not been a problem. I recharge when the voltage gets to 11v.
There are some threads that quote the use of a particular Diode that will drop the voltage of the LiPo pack to the level of an NiMh. You can get this part at Radio Shack.
While many Battery manufacturers have told me that using LiPo Tx batteries is safe, JR specifically advises against it as there have been some instances where a component in the Tx has failed due to the higher voltage. Whether or not they could change components within the Tx to support LiPo Tx batteries is another story. One thread told me the exact component and the replacement part to get, but I would have to look that up.
I fly two or three flights per day and it is only during the first week where the voltage is above 12v. It has not been a problem. I recharge when the voltage gets to 11v.
01-13-2010, 01:04 PM
#4
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RE: Transmitter Voltage
My 2 cents worth. I too have a 8103 with a lipo pack. A 3-cell (I am sure the guy above means 3-cell) 2500 mA pack. My background is electronics and I "HOPE" that the design engineer built a little headroom in the max voltage permitted. Having said that, I don't fully charge the battery once it drops to 11 volts. I set my charger to a max charge current such that when reached, I have around 12 volts. I then fly from there back to 11 volts. Since a transmitter does not really push a lipo like one of my heli's, I don't balance everytime either and simply use the regular charge plug for the transmitter, using my lipo charger. So I don't really use the full capability of my lipo in erroring on the side of caution. JR's are not as common at my field as futaba's are and those guys do fill their lipos complety and I have not heard of any issues.
01-13-2010, 01:15 PM
#5
RE: Transmitter Voltage
Interesting, thank you for your input. Funny thing you mention Futaba in that manner because i have heard that Futaba's are more voltage sensitive than JR's. I don't know that to be a fact, it is just something i read somewhere along the way.
