OK... first thing is that the Solar Panel mentioned by the OP is not a great choice for 12 Volt application IE vehicle or camper as it is a 24 Volt (36 Volt open cct) panel. Most domestic installations I am familiar with run on higher voltage Panels and indeed most panels over 160 watts are 24 Volt so not suprised.
You will need a more expensive regulator to reduce the up to 36 Volt Output to 12 volts and then the useable power will only be around 60 watts as the maximum current that panel can produce is around 5 amps. The next option is to regulate to the designed 24 Volts and use a DC DC converter to charge the batteries which will give you about 100 to 120 watss depending on losses. Its all doable but I would price out the costs of a Reg and possibly a DC/DC Converter as the Panel needs to be a bargain to make it worth it
About the only trap with power budgets with Solar Panels is they are rated at the Panel and are current limited IE a 120 Watt Solar panel doesn't deliver 12 Volts at 10 Amps (or 10 amp hours if you like).
Rounded out to make the math a bit easier it works like this. The Solar Panel max voltage output of a 12 Volt panel (depending on technology) is close enough to call it 20 Volts so a 120 watt panel is capable of delivering 6 amps (6 amps X 20 Volts = 120 Watts). They will usually deliver a little more than that but the losses thru the cables and regs etc means its ballpark.
The Regulator will reduce the voltage so it doesn't fry any electronics or overcharge the battery but the Reg doesn't increase the current past the Panel capability. This means a 120 watt Solar Panel in a 12 Volt application will give you approx 75 to maybe 80 watts of useable power under max sunlight and optimum conditions (12 volts X 6 amps = 72 Watts). The rule of thumb is approx 2/3rds the rating IE 60 watt panel 40 watts power 120 watts panel 80 watts power.
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