battery cut off

[rcsargento]

Is it safe to use lithium batteries with the 10c? Will it overheat the internal components?

Also, I read that the battery alarm is set to go off at 8.6v or something around there. The 11.1v lithium needs a cut off at 9.6v so it does not get damage; can this cut off be increased?

[Flyinfool]

As far as the cut off goes, you should never allow the battery to get anywhere near that low, you are just begging for a hard crash.
This means that you must keep an eye on the voltage all by your self.
I really wish that I could disable the low voltage cut off on all of my transmitters. I would much rather replace a $50 lithium that was damaged by under voltage than the aircraft that crashed because the TX shut it's self off to protect its battery.

A fully charged 3S pack is 12.6V, I don't know if that will damage your 10c.

I always carry a spare TX battery so that I can just change it out when I get down to about 50% of capacity. Takes me less than 30 seconds to change it.

[rcsargento]

Flyingfool, I agree with you regarding not letting the battery go to fully depleted before changing or recharging. I think I used the term Cut-off wrong. It is actually an alarm that goes off and lets you know when the battery levels are low. I have not tested to see if the 10c actually cuts off at voltages below 8.6v for NiCd or what actually happens.

I asked because lithium will get damage below 3v/cell so if the alarm where to go off at 8.6v then is too late for that battery pack. If the alarm can go off say at 9.6v, then the battery will be ok and there is plenty of voltage left for the radio to function without a problem.

I am planning to fly sail planes as well as helis, for sail planes you can fly for more than 3 hours with out having to land so having an alarm is of great help.

[rcsargento]

well I called Futaba and asked them about the voltage in the radios, they said that lipos are not recommended do to the higher voltages, and that the alarm warning can not be modified. I hope they change this in future radios. I do not understand why they would ship a radio with such large LCD on a 600mAh, it does not last very long at all, i only get about 4 flights.

[Flyinfool]

When I still had the old NiCd 9Z TX with the 600mAh pack I found that a 2700 NiMh pack is the same size and voltage and all I had to do was put on the connector from my old pack and then I could almost charge once a month. Just dont try to charge it with the old wall wart.

My 14MZ uses a 2 cell, 7.4V, 2200mAh LI-Ion pack and is good for about a half hour of programing or 1 hour of flight. But it does have a circuit to shut off the TX to protect the battery, It does this at about 20% remaining power in the pack. I never checked to see what the cut off voltage was.

LCD screen draw almost nothing for power, that is why most watches and portable electronics use them, it is the computer and the RF sections that suck up the power. I have noticed that 2.4GHz sucks a lot more power than 72MHz did, or at least I get a lot less flight time out of the TX battery.

[rcsargento]

I might just do that, grab 8 Sanyo 2700mah AA and use the same adapter. Thanks.