AirCon question

Last summer I spend about $5-600 on fixing the AC on my 97 Nissan SER. After about 5 seals, a high low switch, a used compressor and 5 trips to the mechanic the AC was working for about a month before winter weather hit. Today was the first warmish day and no functioning AC. I bought a recharge can with a gauge and charged the system. I get coldish air but the AC compressor cycles on and off. The gauge shows about 20lbs of pressure when the compressor is not engaged and then goes up to around 60lbs when the compressor is engaged. The little gauge makes it look like I need 30lbs to be good.

My question is should I get a second can of 13a and put even more refrigerant into the system?

I am at my usual stage of knowing just enough to be dangerous. This is where I usually make a stupid mistake that turns catastrophic. I don't want to go back to the mechanic. I have pissed away too much on this semi presentable car in the the last year.

Stick the second can in. IIRC, these cars need something like 800grams, or 2 lbs, to work right. Think the cans are what, 12-13 oz?

Discharge pressure should be between 200 & 300 psi, depending on ambient temp and airflow across condenser, suction pressure 25-35 psi.

AND CHARGE FROM THE SUCTION SIDE IF YOU KEEP THE CAN IN THE SYSTEM!! Sounds like you were charging from discharge side. Those cans have been known to kind of explode if they see too much pressure. That can really eff up your day