I also recommend buying one. If you get it wrong, you'll burn your house down. These things don't give you much warning.
LiPo and LiFePO4 are different chemistries and take different charging. Does it say 3.2v/cell (LiFepo4) or 3.7v/cell (LiPo)?
You can expect a constant current stage of .5 to 2 x C-rate, so if you have a 3000mAh battery, a slow charge is 1.5A, normal charge is 3A, and some support fast charging at higher rates like 2x C, but you better know what you have or it can thermally run away trying to fast charge!
After the voltage reaches 4.2v (for LiPo) or 3.6-3.65v (for LiFePO4), the charge mode is switched from constant current to constant voltage (otherwise the voltage would go up past that voltage and boom. When the charge current in this constant voltage stage drops below .05C to .1C (150 to 300mA for a 3000mAh battery), charging is stopped.
I only write this to give you an idea how it works, but if you get it wrong, or your constant voltage is just a little too high, even 4.25v for the 4.2v case, you can plate lithium damaging the battery and there is a risk of fire. This is why nobody here is going to recommend you try it yourself unless you have some good electronics experience and know EXACTLY what battery you have.
I don't plan to make anyone a schematic for this. Too much liability.
