how many charges can i charge a lipo in a day to be on the safe side?

[speed demon]

I've been doing some testing with an airthunder 4S 5000mah. I have some headlights setup that will drain it dead in under 10 mins. I drain then charge(after it's cool) about 5 times in a day and noticed the mah drop off about 300 by the end charge. I let it sit over night fully charged and the first discharge and charge the mah are right back up within 20mah of the previous day. Also I notice it will hold over 16v for a good 30 seconds on the first and second cylce. After that the volts drop below 16v right after I connect it.

Just some things I've gathered.