battery question
 

alright I have a 4.8volt 700 mih nicd battery charged it and all it takes is 5.35 or close after a 7min flight give or take it drops down to 4.9volts tried cycleing this pack and same evertime I going with this is trash what you all think I am scared to keep this thing cause I have to charge it right after a flight not right. I am using a field charger everyone I talk to says to charge it at .7 amps I have tried this and also .5amps get about the same results. Anyone out here have one of these packs what results are you guys getting I think this is a bad one cause its about 3 years old so its time for a newone I think

RE: battery question
 

I would get a new one!!

RE: battery question
 

Sounds like a good pack to me. 4.9 volts is a safe voltage. You can very safely continue to fly until the pack reaches 4.8V, at which time there will be about 50% of capacity remaining in the pack.

RE: battery question
 

Actually, you can safely fly down to 4.4 volts on a 4 cell battery but the voltage takes a nose dive at that point so it is better to stop at 4.6 volts leaving you a bit of waffle room. As said above, at 4.9 volts you have only used about half the available energy.

RE: battery question
 

guys you are just guessing here.
i quit using 4.8 packs a long time ago because 6 volt packs add a bit to the safety margin.......in fact, all but one of my planes use 2 switches and 2 packs(6V). the lightest packs are 3 oz so i only suffer an added 1.5 oz vs a single 4.8 pack................of course that's a whole nother subject.

to the pack in question, it does sound like it's close either way, but you don't really know unless you cycle the pack on a cycler.
the pack should read well over your voltage fresh off the charger, but not always is the case.
if you can discharge the pack, then charge it full again, then discharge and if it's within 10% of capacity, then it's safe to use........anything below that and i would not take the chance.
batteries of your capacity are cheap, especially in terms of what you have into the model right?

RE: battery question
 

And (nominally) a fully charged Nicd pack should read 4.8 volts...you are only knocking off the overcharge. Have no worry but if you want more confirmation a cycler will tell you how much mA's you are getting out of the thing.
Evan, WB #12.

RE: battery question
 

Hi!
I would advise you to get a new 2100-2800 mAh NiMH battery instead of that old 700mAh NiCad battery

RE: battery question
 

It sounds to me as though what is really happening is you have a charging issue and you may not be using the charger properly. Many types of quick field chargers are timer chargers with an auto cutoff and may or may not be peak detecting.

If you really want to know just charge your battery with an or ordinary 50-70 mah wall charger for a full fourteen hours and then check the voltage with your loaded meter.

John

RE: battery question
 

There is nothing wrong with using your 700 mah pack, that is all that was used back a few years and we got good service out of them. If you want some good info on batteries, check out the following sights, especially the first one:

http://www.hangtimes.com/redsbatteryclinic.html
http://www.camlight.com/techinfo/techtips.html
http://www.whenshtf.com/showthread.php?t=2153
http://www.srbatteries.com/nimh.htm
http://dansdata.com/gz011.htm
http://users.frii.com/dlc/battery.htm

You will find a wealth of info in there and it will pay you to take the time to read them.

and, summerwind, we are not just guessing as some of us have been in this business for longer than you have been alive.

RE: battery question
 

the OP hasn't posted any real data on the battery concerned and you have answers suggesting he is good to go?......yep, you're guessing pal........as for age, i'm very close to you, so you must have started business during the tube days.........glad i don't ask for your advice.......i'd be crashing.

Jaka hit the nail right on the head though as usual...........dump this 3 year old pack and buy a higher capacity pack.........cheap insurance.

i do agree on reading the first link on the old timers post though........1 hour there and you'll learn more than oldtyme man can teach ya with his old time tech.:D

RE: battery question
 

still thinkin eh?:D:D:D

RE: battery question
 

The voltages given in the original post by poison are right on for a good 4-cell NiCd pack. Three years is not particularly old for a 700 mAh NiCd pack - such packs often last two or three times that long when charged correctly. However, summerwind is correct, the safe thing to do is to cycle the pack to check capacity, then check the self discharge rate over a week per the directions given on the link to RC Battery Clinic.

With regard to replacing the pack with a 6V pack or a higher capacity pack, that decision depends upon what posion is flying. If he is flying 72 MHz with a 40 sized plane and standard servos then the 4.8 V 700 mAh NiCd pack is a fine choice and is more robust, more economical and arguably safer than both higher capacity packs and 5-cell packs. If he is on 2.4 GHz then he really should be using a 6V pack. If he is flying 2.4 GHz, larger models, more servos or digital servos he might want a higher capacity pack.

Redundant packs with two switch harnesses is an excellent safety measure if one can afford the extra weight.

The notion that larger capacity and higher voltage is always better is an over generalization.

RE: battery question
 

i don't know if I want to keep flying at 4.9volts on my meter when I have seen two people clamed they crashed due to no control and there battery level was 4.8. I had battery in helicopet with high torque servos

RE: battery question
 

so summerwind your saying to discharge than charge than discharge again and it needs to be 10% of what it was full at? witch would be capacity right