how long these batteries last? when and how do I makes sure my batteries are in top performence condition

Thanks

There are some that will say that cycling your batteries is the most important thing you can do. Others will tell you not to worry about it.

Me? I do it occaisionally (like once a year in the Spring)... If I remember to do it.

www.rcbatteryclinic.com

this site will explain you everithing......... made by an expert

How can there be no definite answer? Hasn't anyone done experiments to see if cycling has a benefit? It looks to me like if there was a significant benefit, everyone would be in agreement.

experiment have been done, the results of them are that frequent cycling will shorten you battery life, cycling once a month is a maximum in my opinion

Since I had a set of batteries survive 10 years... never cycled ONCE... the cycler is obviously not a necessity.

The primary purpose of a cycler really is to measure the current capacity of the battery. This is a test to see if the battery is in the early stages of failure. The cycler can definitively test and find a 5% loss of capacity.

You will find that capacity varies with the temperature of the battery. (kind of interresting to play with this. ) And capacity will vary with usage of the pack. The first cycle of a brand new, never before charged NiCd will be short. A couple of charges later will be your maxmum, then it will begine a very slow decline. (nearly a flat line for a long time) Colder means more capacity up to a point. Hotter is just too dangerous to play with. (NiCds can explode if too hot) Taking a battery that was charged when warm and then cooling it... you will see a marked reduction in what you can get out of it.

An annual or semiannual cycling test program is a good idea. (you'll know your battieries' conditions) Monthly cycling of NiCds that are not being used (when you put the airplane up fr the wnter) s a good dea too. NiCds that are not used tend to go bad faster.

The battery clinic site tells more... and better detail. This just works.

I'm new to planes but not to RC. Running and racing electric RC cars, we deal with battery issues. In electric racing, having a battery that is not well care for is like having a wore out nitro motor.

First off if you use NiMh (Nickel Metal Hydride) you can charge a partially drained battery with no lasting problems. With Nicd (Nickel Cad.) you ideally want to drain the battery before you recharge. Over time a battery that is not fully (fully being to cut off, not completely dead) discharged will develop a memory. The battery may still last a long time, but at some point the voltage output drops to a low level causing a false dump. In electric car racing, you will see cars that go fast then start to slow, this is due to the power loss a NiCd battery has as it goes through the discharge cycle. The memory will cause this to happen sooner. If you look at RC car batteries you see all sorts of matching and time claims and a price reflecting this. This is where they match cell and create the best combination of cells to provide longer more powerful lasting packs. The receiver packs are pretty much all just non matched packs.

Now for the cycling, you don't need a special charger to cycle them. All you need is a car taillight bulb (like a 2257) that you use to drain the remaining charge in a pack before recharge. A single bulb is fine for a receiver pack and will allow each cell to discharge equally. Don't let the bulb go all the way out, you will see it start to go dime as the voltage drops. I let mine go until the bulb element is just glowing red hot. The let the pack cool a bit and charge fully. You don't need to do this every charge cycle, but when you have time and think about it.

With a receiver pack battery, you may not notice the reduction in performance as it happens slowly and you are not demanding that much the battery. As the battery begins to dump (what we call the point at which your battery is to discharged to perform) your servos response will be slower and weaker. I have NiCd packs that are close to 20 years old, they work fine and only lag in the capacity compared to modern NiCd's. I have also got new packs that went to junk in about a year. Like anything, you can get good and bad performers.

With NiCd's a little care, can help ensure long life and reliable discharge while in your plane. Imagine how bad you will feel when you crash your New P-51 due to battery dump.

If I confused you, read up on batteries at some of the RC car sights. Just remember there is a big difference in care between a NiCd and NiMh.

NiCD memory effects is a myth. It does not happen unless you discharge the pack to EXACTLY the same voltage dozens of times.
Dennis-

I cycle my packs a couple of times a year. WHen I see that my packs don't obtain 80% of their rated capacity, I replace them.

Cycling, is very usefull. It lets you detected bad cells on the ground, instead of in the air. hehe. Usually, a pack will let you work for 2 hours, if it is good. Make sure that you set up the cycler right. Also, if you really want to be cheap, once you get home, turn on your plane, and leave it until the batt. voltage on the reciever is 4.4, (5.5 for a 6 volt). Check it everynow and then. Once it is discharged, charge it back up. The Getto method.

Okay guys. During my duties in the Coast Guard, I was attached to a marine safety office in the San Francisco Bay area. We had portable radios that worked on Nicd batteries. These radios were operated basically 8-5 every day, M-F. When I got there, it seemed like every time we responded to a pollution incident our radios would fail after about 7 to 8 hours of use. And believe me, EVERYBODY wanted to have a portable radio and we had to supply them to the cleanup contractors so they could talk to us. The radio batteries should supply power for approximately 12 to 15 hours of use. After talking with representitives from the radio manufacturer and the Coast Guard electronics repair people, we determined that the radio batteries had developed a memory that said they only needed to supply power for 7 to 8 hours.

Needless to say, I had to convince my command that we needed to purchase new batteries for the radios and a special charger that would automatically cycle the batteries every time they were plugged in. After I implemented this procedure at my command, we were routinely getting 15 - 20 hours of battery life from our Nicds.

Just food for thought from past experience with Nicd batteries.

My suggestion based on past experience with Nicd batteries, I would COMPLETELY discharge the battery before recharging EVERY time.

Larry

You bought new batteries............ Of course they will last longer. [X(]

needless to say that the "MEMORY EFFECT" of a battery pack is a pure fiction

New batterys will last longer, however cycling them won't hurt.

Back when I was in the Coast Guard, it was candles and row boats.. Just Kidding CGCOMM3RET, The Coast Guard thing caught my eye as I spent 4 years in the CG. You battery experience enforces the effect of battery neglect well.

You want to see how important battery care is, go ask any Electric RC car racer and look at their gear. Then ask how they do in a race and look at the battery care the guys who beat them use. Not that a plane demands that much of a battery, but to answer the original question, proper care, cycling included will extend the working life of a NiCd.

The Electric RC car guys, they take volts of each cell, match cells, measure run times, charge times, graph discharge volt drop. It is amazing the care they give their battery but makes sense as it is the primary power source. Now for the demands of a receiver pack, a little care can go a long way. cycle when you can and go have fun.

Thanks for all the info guys.
after reading all this I came to a conclusion that I should cycle my batteries at least a couple of times a year, eventually new batteries will have to take the place of the old ones so i'll use mine as long as I can.
one day i'll add my experience with cycling batteries as well.

have fun flying/racing/driving/protecting the world/watching t.v?

I am not going to pretend to know the correct answer, but do cycle mine once per month. Although in the cold like we have had, I am not making sure this is done every 30 days. I did, however, notice something ironic here. The persons using the batteries in cars seem to take better care of theirs when the only thing that would happen is the car will slow down. On the other hand those that fly have the entire plane to lose, and are less strict. Like I said, just an observaton.

We all have diferent opinion about how should be maintened battery packs. I had my own one also, and like most of us I tried to explain to other fellows that my method was the best.
Folks, let's be serious...... What is exactly our background with battery operations and what are exactly our theorical knowledges about battery designs and the way they work ?

I discovered www.rcbatteryclinic.com, and my opinion about the way a battery pack should be operated and maintain totaly changed.

This site is done by a guy who DESIGNED battery packs and worked in battery it's entire live.

I consider this site to be the battery pack bible !

You will see that plenty of things we think are wrong..........