Re: 7.5 amps coming in from solar panels VS battery bank size
7.5 Amps to a 1200 Amp hour battery bank isn't much:
7.5 * 100 / 1200 = 0.625%
It is recommended that battery charging be at a rate of at least 5% of the Amp hours, and maintenance (float) can be less so long as it stays ahead of the self-discharge rate. That last item will vary according to the type of battery and its age. 0.625% won't meet any of these criteria.
I don't know where that "35 Amps" number came from, as that's about 3%. Self-discharge is usually only about 1% per month (as mentioned, depending on battery and condition).
A 1200 Amp hour battery bank would want at least 60 Amps of peak charge current net - in other words, without any loads.
That's a pretty darn big battery bank at any system Voltage. Normally you size the bank to handle loads demands and size the solar to recharge it properly. It would be more accurate to say the size of the battery determines the size of the array, rather than the array size limits the battery capacity.
Always a good read, the battery FAQ's: http://www.windsun.com/Batteries/Battery_FAQ.htm
1220 Watts of PV, OB MX60, 232 Amp hrs, OB 3524, Honda eu2000.
Ohm's Law: Amps = Volts / Ohms
Power Formula: Watts = Volts * Amps