jg95762

My Feedback: (2)

I am setting up my first glow plane which is a 40 size with 5 standard servos. I have a 5 cell 1100mah NiCD receiver battery. How many flights should I expect to get in before I need to recharge? What is the best way to check the charge remaining in the pack? How much does the voltage need to drop before recharging? I am thinking of getting one of those voltmeters with red/green lights - where is the best location to mount/install it?

42etus

My Feedback: (2)

How many flights?? That depends on how aggressive you fly and how long your flights are. More servo action = more battery power used. On a trainer, flown mildly I'd guess you'd get perhaps 6 flights from a 1100mah pack. I'd suggest you get something like this http://www3.towerhobbies.com/cgi-bin...&I=LXWW16&P=ML to check your flight pack. For a plane mounted voltage checker I suggest this http://www.voltmagic.com/ . Mount it where you can easily see it and it is out of the way of the engine's exhaust.
Paul

ChuckW

As long as that battery is fully charged when you arrive at the field, you should get several nice flights out of it. As has been mentioned though, a good volt meter that applies a slight load is cheap insurance.

Nathan King

It is always important to test the battery before flight. You cannot assume that just because the battery was plugged in, it was charged.

ChuckW

Exactly, assumptions lead to crashes.

spadeng

rcbatteryclinic.com there is instructons to build your own loaded voltmeter, I got a cheap voltmeter and you wire a lightbulb in series with it and plug that into your charging jack with the power off before you fly. this way works really well as long as you check the voltage before you fly.

jaka

Hi!
Around 8-10 10min flights!
33 years ago when I started it was common to use 4,8V 450mAh batteries...and the flew fine for 4-6 10min flights!

Nathan King

To be more specific:

A 5 cell Nickel Cadmium battery has a nominal voltage of 6 volts. With the Ni-Cd battery chemistry, as a rule of thumb, the battery needs to be recharged when the voltage drops below 6 volts. Remember, voltage readings are just an approximation of capacity derived from the predictability of the particular chemistry. To get a closer reading of capacity used per flight you will need a charger that gives Ampere readings. Cycle the battery and get the "true" capacity of the pack. Now, use the fully charged pack for one flight. Charge the pack back up and read how many milli-amperes the charger put in. This is an approximate drain for one flight. Take 80% of the true capacity and divide by your milli-ampere reading for one flight. The result is a good estimation of how many flights you'll get.

My guess is that you will get about four or five flights.

dignlivn

FWIW,

I use one of these, http://www3.towerhobbies.com/cgi-bin...&I=LXEYM6&P=SM

To check my 4.8 2000mAh nMh pac. I am happy with 4 flights out of a fully charged
pac.

Bob