how doi know how much battery to use
 

o.k im wonderin how u knowhow long at battery would last is there a calculation.

how doi know how much battery to use
 

Like most things if you have the basic information the calculation is easy. First you have to know the average current you are using from the battery (in Amps), then the capacity of the battery (in milliAmp hours).

Divide capacity by current, multiply by 60 and that's how long the battery will last in minutes.

As you see we can't be much more precise without some idea of what battery you're talking about and what you are using it for. I have batteries with capacities from 50mAh to 3000mAh and systems with average currents between about 100mA and 30A.

Steve

how doi know how much battery to use
 

o.k im using it with a hand launch joy glider(no engine) with 2 micro servos.it has 4 small batterys inside a wrappimgits probly
_____________________
{ 1 1 1 } <its about this size
{_____________________} <
it doesnt say anything on the battery though. arough estimate like 5 ,7 mins would be great

how doi know how much battery to use
 

ASCII art to show sizes is completely useless. How do you know what size monitor I'm using and at what resolution ?

If you don't even know the basics like what CAPACITY (mAh) pack you're using your guess will be as good as mine. Could 10 minute, could be an hour or more.

What you're doing is the equivalent of asking how far a car will go on a tank of petrol when you don't know either how much petrol the tank holds or how much petrol the car uses per mile. Sorry, can't help.

Steve

how doi know how much battery to use
 

I think what Mike is really trying to find out is how long he can fly before his receiver battery is too low.

Mike, there's a couple of ways to find that out. Steve gave you one where you can work things out mathematically. To do that, you need to know the capacity of the cells. Usually that's printed on the pack. Even if you find that out, you don't really know their true capacity. Age and how you use/maintain them effects how much energy they can hold. The way to find out the true capacity is to use a cycler that will charge and then discharge the pack, keeping track of how much energy it stores. Maybe somebody at your field or hobby shop could help with that?

A more practical way in the field is to use an expanded scale voltmeter, or ESV. This tells you what the voltage is on your pack, and knowing that you can make a decision on when to stop flying. Some companies now make a little device you can install right on your plane to give you an idea of if it's safe to fly or not. Great Planes makes one called Voltwatch.

If your pack is relatively new and you've taken proper care of it, you can probably quite a bit of flight time out of your glider. Two micro-servos and a receiver shouldn't draw all that much juice.

how doi know how much battery to use
 

Mike, Their is a group that flies off of Brookville dam in Brookville Indiana that fly for 4-8 hours continuously. They use Alkaline batteries. While I don't know the details, if you charge your pack before you come to the field, you should not have any problems!

how doi know how much battery to use
 

hey guys thanks for thehelp.brookville ,hmm how far is that away from ireland,im sure i could mod the plane to fly that far j/k.

lucky enough i fly in a huge field behind my house

how doi know how much battery to use
 

this is what i can see through the red coverech ha N-110AA then 1.2V and 110mah.


any help,its just that and a micro reciever and 2 micro servos in a small enginless hand launch glider

how doi know how much battery to use
 

On a 2 channel glider with micro servos, a 110 mah battery will probably give you a 90-120 minutes.

how doi know how much battery to use
 

really damn thats long.its small and has that written on 4 of them.there like 1/2 the height of a aa battery but about 1/4 thicker