Advantages of chaining another battery to 130Ah AGM deep cycle 12V battery
You need more than 150% of the power you use if you are using very low resistance parts. Otherwise you will need more. In the real world, typical solar panels don't actually produce what they are advertised to produce. In the real world batteries need more power than used to replenish their power with. Only the purest, least resistance batteries give extremely efficient recharge rates. Most produce heat and some swelling in the battery (AGM) which is loss of power. And you need a higher level of power offered to the battery than it currently has in order to charge it. I recommend double your perceived power achieved. Remember, only 1/3 the day is usable daylight typically, so if you want to use the battery after dark, the numbers get alot bigger. Never discharge a 12v battery under 12v whenever possible, and ABSOLUTELY NEVER allow a battery to remain in a discharged state for any period of time if possible. I have assumed lead acid batteries here, but they are all similar in the problems associated with them.