I have very little experience in electronics and only know the basic

math equations and funtion of all the basic components from resistors

to transistors. i have just started reading my first book on beam

electronics and need to know how to charge a battery pack. I took two

cordless phone batteries(one 3.6v 400mah the other 3.6v 600mah) and

wired them in paralel to get a 3.6 1000mah battery pack (is that

right?). What is the perfect voltage and amperage for charging this

pack? If I wired the pack in series, then how many mah would I have?

How would i charge this new pack?

Thanks in advance!!

You need to charge them separately. It's simple & cheap.

Get a 12V DC wallwart, 2 LM317 voltage regulators and 2

resistors. Wire it up like this:

---------

+12V ----+-----in| LM317 |out------+---Batt1--+

| --------- | |

| | | |

| +---/\/\/\-----+ |

| R1 |

| |

| |

| --------- |

+-----in| LM317 |out------+---Batt2--+

--------- | |

| | |

+---/\/\/\-----+ |

R2 |

Neg----------------------------------------------+

Batt1 is the 400 mAh pack, batt2 is the 600 mAh pack.

R1 is a 33 ohm resistor. R2 is a 24 ohm resistor.

Be *sure* to connect batt1 to the 33 ohm resistor

and batt2 to the 24 ohm resistor. Note that the

batteries are *not* in parallel or series. The

negative side of both batteries goes to the negative

from the wallwart. The positive side of each battery

goes to its own LM317/resistor combination.

Charge for 14 hours.

Do not use these batteries in series. Doing so could

damage the 400 mAh pack.

Ed