Charge controller and Diversion Load Controller on the same system?

hey guys, as far as i know, the fountain solution is possible, but impractical and the grid tie solution is impossible.

for the fountain, you would have to make sure that your loads (fountain(s)) could meet the whole production side's output.  then you would have a diversion load controller set to just below the voltage that your normal controller cuts out. 

the problem with this is that likely the diversion load kicking on will lower voltage and cause a see-saw effect.  i have heard of folks using timers to pull this off, or something like a relay driver, but the effort and cost put in (in my sole opinion) is not worth the end result.

i would just run the loads you want on the load portion of the controller.

 or you could use a dc timer during the best hours of the day, if you see continual controller regulating or "wasting" of power.

james
Alt-E staff

well, that is a good problem to have.  run more loads, especially midday.  if you want to run a fountain, you could have it on a timer like this

http://store.altenergystore.com/Enclosures-Electrical-and-Safety/Miscellaneous-Electrical-Parts/Switches/Timers/AEE-FlexCharge-Digital-Timer/p2342/

and run it sometime in the middle of the day when your output is likely the best.

james
Alt-E staff

Hey Keith - so in your schematic, you have both charge controllers hooked up directly to battery #1, right?  The first being used to charge from the PV, the second acting as a diversion load controller which would be powering the second load as long as the voltage on battery #1 was above a certain threshold?

My only observation there would be that if you've got the wires from both controllers connected to the same terminals on the battery, then controller #2 would be reading the voltage coming from controller #1, wouldn't it?  Thus, as long as the PV was lit up, controller #2 would think the battery was fully charged and would be powering the second load - even if the battery was dead!

That said (and assuming I read your schematic correctly), I think you are on the right track here!  Now, how can we get each controller reading the voltage of battery #1 without interfering with each other?  I haven't yet seen a battery with two sets of terminals...

Hey Ryan,
Actually, the batteries I'm using, do have two sets of terminals.
See:
http://store.altenergystore.com/Batteries/Batteries-Sealed-Agm/MK-8A31-AGM-105-Ah-20-Hr-AGM-Battery/p769/

And, when I test my battery, with a meter, I see what appears to be the battery voltage ... not the controller's input.  At least I think that is what I'm seeing. It definitely goes down with consumption!