Recently I bought a Taiyo r/c f-16, which is similar to this below:

http://www.rakuten.co.jp/ggimport/658403/667691/681698/

The plane comes with a small 6V 3-cell NiMh battery and a field charge. After some simple assembly and testing, I realise that the plane motor works well, but the battery sucks - could not sustain the motor at full power for more than 40 sec. []

I'm thinking of replacing the stock battery with another 6V battery with higher capacity e.g. using li-po to improve the flight time, but I'm not sure how to go about it. What are the things that I need to look out for? [&:]

Appreciate if any one of you can help or direct me to some place where I can find the info that I need.

If you are looking at lipo's, make sure your ESC has a LiPo cutoff programming option, and that you stick to a 7.4volt 2 cell lipo, a 3 cell 11.1 volt will most likely fry your motor in about 30 seconds. You may be better off and safer just getting a better brand name NiMh battery, look at the mah number on the battery (ex: 1300mah). The larger that is the more flight time you will get.

Hi fliprob17,

Initially, I have though of using a higher capacity 6V NiMh battery, but I think the stock EDF of the F-16 may not be strong enough to bear with the payload. May have to end up changing everything inside...

I'm thinking about Lipo because of its high capacity-to-weigh ratio, and I'm confident enough to modify the plane (made of styrofoam) to fit in different sized batteries..but it's the circuitry that I am inexperience. You said if I go choose Lipo, I should "ensure that my LiPo has a cutoff programming option, and that I stick to a 7.4volt 2 cell lipo." What exactly is this cutoff programming option? I'm afraid the f-16 that I have don't have a ESC, only a simple circuitry that switches the EDF either ON or OFF...[]

You need to match Volts for Volts, that is, if the stock battery is 3V, you need to come as close to 3V as you can to avoid burning out the motor and other onboard gear in the plane. Being an RTF, its capacity is certainly very limited.

Replacing a 3V with a 6V will practically guarantee a burnout.

The LiPo does not have the cutoff, some ESC's (Electronic Speed Control) have an auto cutoff programmed for LiPo batteries. Again, going to a LiPo with the sotck radio equip. is a risk, you could fry everything. Try looking for a 6v NiMh battery that maybe has a little more capacity or mah. The weight difference should be next to nothing if you stic with the same amount of cells as the original battery. Just going to a brand name of the same battery would make a difference. The stock batteries are just about worthless.

According to the writings on the stock NiMh battery, it actually says 6V (though its mah is not specified), so I'm just guessing a 7.4V 2 cell Lipo may work...

But an additional question - I notice that a ordinary Lipo battery has 3 wires coming out while ordinary batteries like the NiMh only has two i.e. + and -. What's the third wire for?
[]

LiPo's have two wires that go to the connector, positive and negative, that then plugs into the ESC. The other "set" of wires with a 4 or 5 pin plug is for balancing the LiPo with an appropriate balancer..

Thanks for the advise! Guess I'll stick with a better 6V NiMh for the time being. Don't want to fry the plane on her first flight...