I have a Hobbico Nexstar (aprox 4 months old) that came with a Nicad 4.8V 600ma battery pack. The older guys at my club told me not to fly once the voltage dropped below 5.0 on the meter. This usually happens after 2 or 3 flights. Can I change the battery out to something with a higher amperage and would that then give me more flight's (hold the voltage longer) ? Like a 4.8V 1000ma if it even exists ??

Thanks!

Yes, you can buy a bigger battery pack. But you don't need to. You can fly at 4.6 volts on the meter. Make sure the meter you're using has a "load" - usually about 300 mA. Are you using a device designed to measure voltage "under load"? A typical 600 mAh pack should give you at least 60 minutes of flying for a trainer type of airplane (4 or 5 servos) on a .46 powered glow plane.

I am using the Futaba BR-2000 Checker. I am not sure if has a load? If it does does that make the voltage appear lower than it actually is?

[8D]

The futaba battery checker is one like he was saying to use becuase it checks batterys under load. But I disagree with him about running your batterys down to 4.6 volts thats a good way to lose your plane when the battery goes dead, 4.8 volts is the lowest I would go. Yes you can buy a higher amp pack up to around 4000milliamp hours, but a battery between 1500 and 2000mah should be a good battery for you.

http://www.horizonhobby.com/Products...rodID=JRPB5001

When I got back into the hobby, I had to replace my batteries anyways, so I "upgraded" to 2000 ma, I dont' worry about flying time, if you are planning on being in the hobby for a while, put a new bigger battery on your buy list.

just my 2 cents

Jon

heres a little insite from a NEXTAR owner when I was flying mine on a regular basis my battery would run down rather quickly,I checked my battery with a Volt-watch and it would show the voltage ran down too quickly like yours does,I eventually replaced the battery with a new one with the same 600 mah battery that came with the plane and it held a charge for many flights at least 5-7 per flying day.
these planes have been sitting in a warehouse for a long time and weather or not they have a charge they can go bad over time I think they actually last longer when they have a charge in them of course a larger mah battery will give you a extended flight time and the security of knowing that your not going to run out of juice, I have a couple of planes with the 600 batterys and they don't drain down that fast and they have 5 servos its possable one of the cells is dead or dieing and not holding a full charge and so its draining down quickly as well.

The Auto Levelling System (ALS) will probably contribute to battery drain if it isn't disconnected.

Go and get a new battery. If you don’t one day it might just be at 4.4 volts and you will takeoff. Your plane won't be happy and neither will you. I went straight forward and got a 1500mah battery. It doesn’t coast alot and won’t hurt anything so it isn’t a big deal. And like someone said here those batteries sit for a long time and do go bad.

Thanks for all the insight. I'm going to get a bigger battery just to be safe!

Thanks again

A new battery certainly won't hurt anything.

Here's something else you can try. Fly your normal 3 or 4 flights on the old battery. Quit flying when it gets to 5.0 volts (like the "old guys" recommend). Take it home and set it up and move the sticks back and forth to simulate flying. Move the servos at least as much as you do when flying. I'll bet you can go another hour before things quit working. Flying down to 5.0 volts is very conservative. I'd bet you are only using about 25% of your capacity.

The ultimate check for a battery is to discharge it with a device that measures how much current has been discharged. These are called "battery cyclers" and may cost about $100. You would charge a battery fully up. Then discharge it and measure its full capacity (it should be about 600 mA). The charge it again, fly three flights, take it home and discharge it. Let's say it discharges 400 mA. Now you know that the three flights took 200mA. (600 minus 400).