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-   -   discharge the batterys good or useless? (https://www.rcuniverse.com/forum/questions-answers-154/8601354-discharge-batterys-good-useless.html)

costarican_pilot 03-21-2009 05:43 PM

discharge the batterys good or useless?
 
so far i have two planes after a good day of flying i never discharge the batterys.. i stop flying because my batterys are low showing a voltage of (4.8) sometimes i just been avaible yo fly around 5 flys of 10 minutes each. i see others plitos flying 8-10 flys every day whitOUT diying the battery... i ask one of my friends how do u get so many flyts on one small battery 4.8? and he goes because i discharge my battery before charging... he tOLD MY JUST TURN ON UR PLANE AND TRANSMITTER AND LET THE BATTERY DIE AND THEN CHARGE IT AGAIN AND I WILL GET U BETTER RESULTS? ITS THIS TRUE?

MinnFlyer 03-21-2009 06:01 PM

RE: discharge the batterys good or useless?
 
Bad idea. Discharging the cells below 1v (1v each - 4v total for the pack) can damage them.

First of all, a standard battery pack is SUPPOSED to be 4.8v - When you initially charge them, you'll get a little more, but when you use it, it will drop fairly rapidly to 4.8 and then it will stay there a long time... Then it will drop rapidly.

That said, 5 flights of 10 minutes is usually about right for a standard battery. If you want more, you could buy a battery with a higher capacity. Most packs that come with a radio are 600MAh, you could get a 1200MAh pack and fly twice as long - Just remember, it will also take twice as long to charge.

aerowoof 03-21-2009 06:04 PM

RE: discharge the batterys good or useless?
 
you can damage batteries by discharging to a too low voltage, a discharger/charger only discharges to a safe level and then recharges plus alot of them will tell you the total capacity of the pack.this is good to know as a pack ages it's capacity in mah decreases.This means that while you were able to fly 5 flights you may only be able to fly one.Most recommend battery replacemet once capacity drops to 75% of the rated pack.fo instance a 1000 mah pack that is showing a capacity of 700 mah should be replaced.

costarican_pilot 03-21-2009 06:15 PM

RE: discharge the batterys good or useless?
 
mmm thank you guys..... i think i will have to change the batterys on my planes if i want more time to fly.. or just take my charger to the field and wait to charge... one more questions for can i left my planes charging during the entire night? or that will damage the battery 2?

MinnFlyer 03-21-2009 06:33 PM

RE: discharge the batterys good or useless?
 
I usually leave them overnight the day before I fly

costarican_pilot 03-21-2009 06:59 PM

RE: discharge the batterys good or useless?
 
ok thaks!

Luftwaffe Oberst 03-21-2009 08:07 PM

RE: discharge the batterys good or useless?
 
Once a year I cycle my batteries. I made a homemade battery discharger with 12 auto interior light bulbs on a board, all sodered together. I drain the batteries down until the lights are dim, then I disconnect the discharger. I let the batteries cool off before I recharge them back up with the full 16-18 hour charge.


MinnFlyer


Bad idea. Discharging the cells below 1v (1v each - 4v total for the pack) can damage them.

First of all, a standard battery pack is SUPPOSED to be 4.8v - When you initially charge them, you'll get a little more, but when you use it, it will drop fairly rapidly to 4.8 and then it will stay there a long time... Then it will drop rapidly.

That said, 5 flights of 10 minutes is usually about right for a standard battery. If you want more, you could buy a battery with a higher capacity. Most packs that come with a radio are 600MAh, you could get a 1200MAh pack and fly twice as long - Just remember, it will also take twice as long to charge.

Mike B. is right.

If you don't know what your doing it's best to not cycle your batteries, or have someone that knows what they are doing do it for you. I can't prove it however it seems that my batteries last a bit longer. I'm on my 3rd year with one of my mAh batteries, and it still is good as new.

Rodney 03-22-2009 07:55 AM

RE: discharge the batterys good or useless?
 
A gross error in many of the above posts. You will not damage a NiCad by discharging down to zero as long as the rate is not so high as to raise the internal temperature a great deal. What will damage them is to get a reverse charge. If you try to discharge a series string of batteries, then when the weakest one goes to zero the rest of the pack will continue to discharge and reverse charge that weakest cell. If discharging a single cell, it is perfectly save to discharge to zero volts. In fact, in some of the NASA studies, they store their NiCads by discharging to zero volts, attaching a shorting bar across the cell and store at a low temperature as this prolongs their storage life. Note: this is on individual cells, not batteries. The reason for the common 1volt warning is that, if you hold to that, the probability of reversing a cell is next to zero. If you are comparing capacity to factory specifications, you need to discharge down to 0.9 volts/cell as that is how most manufacturers test them.

MinnFlyer 03-22-2009 11:43 AM

RE: discharge the batterys good or useless?
 
Thanks for the info Rodney

costarican_pilot 03-22-2009 04:26 PM

RE: discharge the batterys good or useless?
 
thank you for the info

Luftwaffe Oberst 03-23-2009 04:31 AM

RE: discharge the batterys good or useless?
 
Thanks Rodney, yes I don't drain them down to nothing (Just to be safe.) I drain them down until my bulbs are a dim orange ( I'm guessing just over 1.5 to 1.8 Volts). I guess that any battery that is too hot... can damage them over time, I check to make sure they are warm and not hot during and after a discharge. [8D]

hacker8675309 09-05-2011 10:47 PM

RE: discharge the batterys good or useless?
 
ok guys I have a going debate with my buddys and I. The charger that came with my alpha 40 was for a nicad battery I bought a nimh of the same power levels and went to charge it with the same charger they started in on me saying I and going to wreck my battery... as far as I know power is power.. you have to make sure that the levels are the same. as long as they are the battery should be alright. please help me end this debate. are they right about there being different chargers for different batterys or am I right power is power long as the mh and v match up. please get back to me help me figure this stuff out.. only been flying a few years

Gray Beard 09-06-2011 07:10 AM

RE: discharge the batterys good or useless?
 
Same charger for nicad and nimh. lipo and lifie require a different type of charger. For nimh and nicad it may be the same charger but chargers are usually set for a max mah. I have one good charger that is fine for all my nicad and nimh packs but it only goes up to 1500 mah then goes into trickle mode. Most my packs today are above 2400 mah so they don't get a full charge on that charger. I charge them on one bigger charger then trickle charge on the other charger. I bought my trusty old charger when a big pack was 1200 mah. It works great but it has it's limit.

Oberst 09-11-2011 11:58 PM

RE: discharge the batterys good or useless?
 

ORIGINAL: MinnFlyer

Bad idea. Discharging the cells below 1v (1v each - 4v total for the pack) can damage them.

First of all, a standard battery pack is SUPPOSED to be 4.8v - When you initially charge them, you'll get a little more, but when you use it, it will drop fairly rapidly to 4.8 and then it will stay there a long time... Then it will drop rapidly.

That said, 5 flights of 10 minutes is usually about right for a standard battery. If you want more, you could buy a battery with a higher capacity. Most packs that come with a radio are 600MAh, you could get a 1200MAh pack and fly twice as long - Just remember, it will also take twice as long to charge.

Exactly. Very true, don't do it! I'd get a charger system that has a cycler system built in. It will safely discharge and trickle charge your old batteries and will tell you if you have a bad cell or not. I have batteries that are over 8 years old and they work as good as the day I bought them. I have them cycled once every 3 years to make sure they are in tip top shape and can still use them.

I usually do it the cheap way and keep a few electric flyers around. I just give them my batteries and they do it for me.

I'm Luftwaffe Oberst, and last time I did my old method I forgot that I was draining them killing one battery, and my other one exploded. So I stand corrected to what others claimed. DON'T DO IT!


Pete


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