rcj

I forgot the reason why nicad are preferred over nimh for receiver power packs...can someone answer this?

Also, how do you go about building a receiver battery pack? I planned on using 5 "aaa" or "aa" energizer nimh cells to make the power pack. Do I weld the ends together or is there some kind of adhesive that's easier to do without fear of damaging the cells?

P-40 DRIVER

Do not, I repeat, do not build your own reciever packs, leave it to the pros! Improper technique can easily damage cells risking an airplane to save a couple of bucks is not worth it. Battery packs are cheap, go buy what you need. Nicad packs will last longer and have a lower internal resistance at the expense of higher weight. Go with nicad unless you have weight issue and charge it overnight at 10%.

alan0899

G'day P40,
I totally, completely & utterly agree.
In case I was not making myself clear, DON"T try building your own packs!!!!!!!!!!!

rmh

- I build all of my own packs - made from just two A123 cells - 6 v - 2300ma
In my book -there is nothing on the market to compare as they have the best capacity to hold voltage under load and can be recharged almost instantly at 8 amps-

Dr1Driver

When I first started using 5 cell packs, they were not commercially available except from SR ($$$), so I made my own. It's a PITA. The soldering is difficult and must be done quickly to prevent the heat from damaging the battery. You should be an experienced solderer to build a pack. You must glue the cells together to prevent vibration. Hot melt glue is usually used here. Now, you should wrap the pack in something. Large shrink tubing is available ($$$) at your local electronics store, or you can use plain old electrical tape. Now you gotta solder on the leads. See what I mean? Unless you have a special voltage, amp, or configuration need, go with the commercially made stuff.

Dr.1

rcj

P-10,

When you say nicad will last longer, do you mean useable cycle times or number of cycle life. I'd agree with cycle life from all the reading that I came across on the subject. But nicad has longer cycle times because nicad keeps a voltage steady (flat) longer than nimh?

To all,

Which do you use nicad or nimh for receiver packs? Do you notice any difference between them in use?
What I like about nimh for receiver pack (in my truck) is that it doesn't have memory and I can topped it up before racing.
(For some reason, for my experience with nicad and nimh since the 80's, the nicad's doesn't seem to have a flat power output like nimh)

Rafael23cc

My Feedback: (6)

What are you trying to power with NiMh batteries? if it has a low power requirement, then the AA nimh should be fine, you are better off with low impedance nimh cells and those are hard to come by in AA configuration. The higher the impedance the higher the voltage drop across the pack, and if you have a high power requirement, you will drop the voltage below a safe level.

I used to run nimh on my helicopters and changed back to Nicds because I was getting about 1-2 flights on the nimh packs. Now I'm looking a lithiums to be able to fly all day long without worrying about the batteries.

Rafael

BillS

I continue to use NiCad’s because they are better able to tolerate my stupidity about overcharging and self-discharge.

Bill

rcj

Alright, I see some of your points on over discharging so I will get a nicad if I can find one easily. I don't need to worry about overcharging since I have a peak charger (Hyperion EOS 5i) that should work with the power pack I think. I just need to add the right plug. It's too bad that nicad can't really be topped off because of it's memory properties. I will get to use my discharge-then-charge function for nicad on my charger then! Yippee it works out.

Dr1Driver

It's too bad that nicad can't really be topped off because of it's memory properties.

Modern nicads have very few memory problems. The only memory problem I know of is when the pilot forgets to charge them.

Dr.1

BillS

You might want to verify but memory problems were a 1960’s condition in the spacecraft under exact same discharge conditions. Technology has improved and radio control use does not discharge exactly the same amount each time.

Bill

rcj

Hi again,

The application for the 6.0V nicad receiver pack is my Futaba R603FF 2.4Ghz receiver and Hitec HS5625MG steering servo (and possibly a 5.0V, .6 watt cooling fan) in my 1/10 stadium truck (XXX-T MF2). Which one would give me enough power and decent times for my application:

1. http://www.greathobbies.com/producti..._id=GHP070N5FS
2. http://www.greathobbies.com/producti..._id=GHP110N5FS
3. http://www2.towerhobbies.com/cgi-bin...=++&search3=Go

Many thanks.

Rafael23cc

My Feedback: (6)

If you're just going to run one servo and a "constant" load, then a nimh pack should work fairly good. My comments on high impedance apply to several servos and high-variable loading on the servos and electrical equipment.

Of course, the higher the capacity the longer you can go between re-charges.

Rafael