self regulation of solar pv

[bob golding]

hi all, at the moment i have 3 250 watt panels. broken glass so putting out about 2/3rds of the rating  short circuit. i am feeding the output straight into my 800 amp hour bank,and everything is rosy. bank is charged and it all seems to self regulate quite happily. i have a tristar 40 amp controller across the bank. i want to add another 3 panels to the system to help in the winter. will adding 3 more panels drastically change this self regulation.?
 i am limited to 960 watts by the charge controller so assuming everything stays the same and i get around 2/3rds of the rated output at maximum sun i should stay within the rating of the charge controller. i tend to be away in may when the panels are producing there most output so wont be around to check everything is ok.
 i could of course just disconnect 3 of the panels when i am away, but i am  interested in the interaction between directly connected pv and batteries. in other words how does the internal resistance of the battery bank affect the output of the panels

i would rather spend money on panels rather than a MPPT controller as i have the space plus a turbine as back up in the winter anyway.

[eddy_currents]

I have two 225 watt panels vertical (or nearly) facing east to catch the rising morning sun, these are 24 volt panels feeding my 12 volt bank directly producing most always 16 amps, as the sun rises and starts to come south my main 1 +kw aray starts putting out and is controled by a C60, then as the sun goes west it lights up some more 24 volt panel that directly feed 20 (max) amps into the bank until sundown (again vertical mount). I have been told and read that your not suposed to, but it works for me and I have lots of power, banks most always full,got lots more panels but no need to put them up. Bank is 1100 amphrs at 12 volts. my rule of thumb is not more than 2% directly fed to the bank (amphr wise). Works for me YMMV.

[bob golding]

 thinking about it, what i might do is keep the arrangement i have now but 2 panels facing south at 40 degrees. the best all round angle for my latitude, and 2 east facing and 2 west facing. that should give me  less power in the middle of the day and catch a bit more in the morning and afternoon without going over limit of my charge controller don't know why i didn't think of that myself. thanks for reminding me.