Hi,
I am new to rc hobby and need some help to choose a baterry pack please.
a)can I use 5cell (6v) pack with jr receiver? (646pcm) Came from factory with 4.8v pack

b)what size cells I must use with a 60in plane ? I see that the cell s weight between aa aaa and biger type cell isn’t much different.so I must use aa,aaa or biger size cells for my pack?

c)the capacity of the cells. I will need them only for the receiver and servo operation but in the price they have at about 2$ diference. If I choose cells with biger capacity (2600) the 5x2600 will be 13000mah. Is it too much?until now i used a 1100mah pack and it is more than enouth for me. Is it more dificoult to balance the cells in the packs when I charge them?

I see that many smaller capacity aa cels is out of stock. Any suggestions?
I don’t want to charge with 13a at 1c.

I was thinking of 5 cells at about 1000-1500 mah with total of 5000-7000mah to be able to charge them with 7A at about 1c or 2c.

d) the shape of the pack is critical?

e)many users suggest 2 packs with two switches at the same receiver. Is it safe? The packs must be identical and I will need a regulator?

f)nimh or nicd?

the reason i want to change my packs is that they are already 3 years old and i dont risc a crash.
please help me to choose a pack
charger used : ICE

Thanks very much
Achilles
Achilles

G'day Achilles,
Ok first off, you can use a 5 cell, 6 volt pack with that RX, sometimes some servos are not suitable for 6 volts.
A 60 inch plane is relatively small, & an 1100 Mah pack will do nicely, unless you are flying with digital servos & flying 3D.
The capacity of the pack, is derived from the capacity of the individual cells, because they are connected in series, so a pack with 1100Mah cells is still rated at 1100Mah, the capacity does not add on.
You will need to charge new packs at 1/10 of its capacity, so an 1100Mah pack should be charged at 110ma. see site, http://members.aol.com/davthacker/balancecharging.htm

I personally still use nicads, because I have had trouble getting NiMh cells that will supply reasonable current, but NiMh packs are good if you can get the good ones.
It is a good idea to replace you batteries about every 3 years, so anything over 1100Mah, up 2000Mah will be good for your installation, remember the larger capacity, means more weight.

thanks for the help Allan,
i am thinking of buying cells (sanyo nimh hr-3u) and build my own packs.
i am trying to find cells with solder tabs , connectors and everything else i will need including instructions on how to do it.
any good place to find that info?
thanks again
achilles

Do not build your own packs, It is very easy to damage the cells by overheating them, leave this to the experts. For a standard 60" airplane running 4 or 5 standard servos, 600-700 mil nicad pack will work fine if your not doing a huge number of flights. double that if your going with digital servos. You may want to add a little more NIMH cells. Charge your batteries over night at 1/10 th thier capacity, 100 miliamps for a 1000 miliamp pack. The Pack that came with your radio will probably work fine and thier is no reason to run 6 volts unless your are running a high performance application such as 3D etc. Sounds to me like you have yourself completely confused about batteries. Don't waste a bunch of money untill you understand whats going on.