I have 4 planes that I normally like to fly. I usually go flying spontaneously and I would like to keep the RX batteries toped off. Do you think it would be aok idea to leave the RX batteries on the charger all the time (after they are fully charged) and have the chargers plugged into an outlet that is on a timer for 30 minutes or so a day? I am wondering if that is a bad idea for battery life or capacity issues.</p>

If you are using the wall charger that came with your radio, set the timer for one hour a day every day after they are fully charged.
This is the best way to keep them charged and ready to go when you are.

Tim

The idea of leaving batteries on a wall wart all the time makes me uncomfortable....too much can go wrong....the timer could fail....thermal runaway on a NiCad......yes it is different than charging over night as with an over night charge you at least see the batteries and charger 15 to 17 hrs......I have heard that you can loose up to 30 percent of a charge over night...30 minutes a day just wouldn't return the battery to a full charge...
Instead why not pick what you're going to fly the night before and stick with your choice or use a quick charger if you change your mind.......
I'd never leave a Lipo unattended....I've seen those burn a couple of times...
But this is just me.......good flyin

I did exactly that for many years and know many other people who do the same. I set the timer for 1 hour a day.

But I also know a very experienced instructor who never charges until he ia driving to the field then he plugs in a peak detect fast charger as he leaves and has toasty warm batteries when he gets to the field.

I can assume that you have no cordless phones in your house.

This is the web site.
http://www.hangtimes.com/redsbatteryclinic.html

This is the link on the site that tells how to do it.
[link]http://www.hangtimes.com/id32.html[/link]

Tim

The using a timer set to charge 30 to 60 minutes each day is an excellent way to keep your batteries ready to go, much easier on the batteries than leaving them on a constant trickle charge. You might want to check out
http://www.hangtimes.com/redsbatteryclinic.html for some excellent advice on how to care for all types of batteries.

Thats what I do also. Now that I am running A123 packs for most of my planes I dont even hook up the charger until I am at the field. 5-10 min and good to go.

Charging Nixx batteries at a slow rate will increase their life.
Inversely, fast charging reduces their life.
Fast charging on the way to the field everytime you fly is not a good thing.
Properly charging and keeping them topped off with the timer/wal-wart is a good thing.

Do your own thing,
KW_Counter

Nope, absolutely not.

I fly with a guy who told me a friend advised him to only use a quick charger, saying overnight charging was bad for your batteries. Obviously there's a lot of misinformation about a lot of aspects of this hobby. I told him that quick charging should be kept to a minimum and the rate used should be at a minimum for the needs at the time. After all, a 3 hour charge is considered a quick charge by the battery manufacturer.

One thing too that you need to realize about a wall charger is they don't supply a constant current like, for example a Hobbico Multi Charger (which is a CC charger). If you're using a 50 ma wall charger it starts out at 50, maybe 55 ma and after the battery is at full charge it may only be 10 ma. So leaving it on the charger all the time isn't as hard on the battery as you might think. I would never do that, I usually just top off with a couple hour charge if it's been a few days since a full charge and overnight if it's been a few weeks.




Mike

I use an old ACE charger and just leave my planes hooked up to them on trickle charge, ready to go at a moments notice. There was a product called the Little Trickler that you would just plug several wall warts into and it would keep your batteries at a trickle charge.

i wouldnt do it, i wouldnt even do the hour per day thing,
your nicd's or ni-mh's will be good for at least 3+ weeks. if they arnt you have a problem
i just charge mine throught the week, then when i fly on the weekend all of my planes/starters/glow starters/transmitters/feild battery/ect are ready to go.

Chopper Mike,
I am confused, are you agreeing or disagreeing.

Your first comment apprears to disagree.
quote:

Fast charging on the way to the field everytime you fly is not a good thing.

Nope, absolutely not.

I fly with a guy who told me a friend advised him to only use a quick charger, saying overnight charging was bad for your batteries. Obviously there's a lot of misinformation about a lot of aspects of this hobby. I told him that quick charging should be kept to a minimum and the rate used should be at a minimum for the needs at the time. After all, a 3 hour charge is considered a quick charge by the battery manufacturer.

Your second comment appears to agree.

Please clarify.
Thanks,
KW_Counter

Opps - Sorry
KW_Counter

ChoperMike, you are correct, there is a lot of misinformation on batteries in these forums. Here is a list of very good info, especially the second and last items, giving you the straight skinny on batteries.

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
http://www.hangtimes.com/redsbatteryclinic.html

NIM batteries don't like heat. The fast field chargers tend to heat them up a bit more then they like. By fast charging them they just tend to have a shorter life. Instead of three years you may only get one or two years out of a pack. That's the easy answer as to why people usually don't fast charge them all the time. I charge at home over night on some of my planes that are hung up and I can't trickle charge them. When I'm at the field and making it a full day of flying and my batteries go down I use my field charger, I really don't care if they poop out on me a little quicker then they would if I always slow charged. Fast charging works but you won't get the full life out of a pack if that's how you always charge your batteries. In my case, BIG WOOP!!!! I'm not going to quit flying because my batteries are low.

I use lipos. They hold a charge for a much longer time, work much more efficiently, and are lighter than nixx batteries. It's just so much easier than trying to keep all your batteries ready for flight at any given point.

If you really don't want to get involved with lipos, then I follow Mr. Greybeard's school of thought - slow charge when I get home, but fast charge the am I want to fly, or in the car on the way to the field. Batteries are cheap enough for me to use them in a convenient way, and spending hours of my valuable time on a $15.00 battery is just asinine.

Many Nimh cells have a high self discharge rate. 5 - 10 % in the first 24 hours then around 1 % per day, higher if stored in hot conditions, so after 3 weeks expect a 30% loss in charge. The higher capacity cells on offer are supposed to have higher self discharge rates.

There are some cells around with lower self discharge rates, often designated as camera cells. Just be sure which kind you have.

I like to be safe and KNOW that my battery packs are fully charged. Hence the full charge then daily top up from a timed charger set up.

Fast charging at the field is inviting a failure. It is only as good as the peak detection on your charger which might and does sometime flase peak. If it does and you are not aware there in lies the problem. Kevin.

Hi!
NIMH cells should never be fast charged first time!!!! Doing this will invite trouble!

It's also vital to slow charge them over night ( 14-20 hours) using your R/C wall charger when ever you want to go flying.
Peak charing NIMH cells are no good, as they are notoriously false peakers!

Rc is a luxary for me with time , between work and my boys ice hockey its my last freedom of choice to fly . I alwasy finding myself ready to fly with no batterys .
Then one day asked the same question , an rcu member suggested a simple $26 purchase called a Lil "Trickler " I now own three , its the best little investmenet I ever bought , batterys on tricle charge , always worked great , never a lost plane due to battery failure , always ready to fly , and best part its a plug and play set up , no sodering ect out of the box ease

I just got a turnigy accucell 6... so far the setup is easy. My big question is how fast should i charge the pack? I am using a 2700mah 4.8v nimh pack.
dan

I use the same charger and I set my charge rate at 25% if I have some time. I never go more than 50%, even if I need it more quickly. So, this would be about .6-1.3 for you.

This is what I have been doing for the last 30 years. I have 4 Ace chargers that charge at a slow rate (C/10) for 15 hours and then switch to a trickle charge (C/50) rate. Also I have added Ace Add-A-Trickle adapters to all of my wall wart charger that provide the same function as the Ace chargers. When I get back from flying I start the receiver packs used on a slow rate. Then 15 hours later the charger switches to a trickle rate which I keep it at until I next go flying. My packs last for years this way and are always ready to go to the field.

Bruce