E-Component collection - charge a battery pack

Hello, I'm a long time tinkerer but never learned electronics, over time I learned a few things about some of the components and some what of what they do, but every time I get to salvage some parts I pick a few things out like Mosfets, heat sinks, capacitors, leds, and so on...

Right now I have an old PC under the knife............. soldering gun.............LOL

Found lots of Mosfets and things...

Prob is I'm an E-Dummy. I want to build things worthless and fun, or actually something I can use like a battery charger...

When digging into something what should I look for thats worth keeping if I was to be making a charger.

I want to charge a battery pack thats 9.9v so say 10v..... and at 3-5 amps.
I'd want it to get to 10v and taper off until its at 12v and stop.

Point me in the right direction oh electronic gurus...

E-Component collection

We cannot tell you how to blow up a rechargeable battery because you didn't tell us its chemistry (lead-acid, Ni-Cad, Ni-MH or Lithium) and its capacity. Seriously, we need the details for charging your battery.

My remote controlled helicopters use a tiny lithium battery that is charged at a low current by a battery charger IC.
My car battery has its charging voltage limited by a temperature-compensated voltage regulator.

Re: E-Component collection

The batteries are A123 cells, 3.3v each and 2300mah and I would be using a 12v DC power source..

E-Component collection

I think I answered your question a minute ago on another website.

You must look at the datasheet for A123 Lithium battery cells. Their recommended max charging voltage is 3.6V so for 3 cells in series 12V is much too high.

They are not fully charged when their voltage reaches 3.6V each, the charging must continue until their current drops to a certain low amount.

Each cell must be monitored so it doesn't over-charge.