#217 -
Renewable Energy > Technical Discussion: Other > Re: Batteries
ok now we are getting a handle on what you have. that vector inverter (using the vec050 as an example)advertises a 90% efficency but that is the power conversion efficency only- there is also a load from the cooling fan "super turbo cooling fan" gotta love those ad men. anyway that load is not counted in the efficency of the unit. its about 40wh. if we run the inverter full time thats about 1kwh a day!
dave. i do hope you have gone over to solarjohns link and spent a few minutes, hours, days reading. he has a treasure trove of info there. go to his 3/28/07 posting and grab his battery soc chart. i lifted it the day he posted it (thanks john) you do have a multimeter? if not go buy two they are cheap. and with two you can cross reference if you don't believe the first reading. follow johns chart for topping off the banks with the honda. as far as adding any and how many new batteries to the bank goes thats for your pocketbook to decide but at fifty cents per amp hour they are a low cost and effective way to go. now here comes the sticky part of this post. if you have your bank wired like almost all the diagrams you see on the web you have what i call a "self amplified battery bank unbalancer circuit" built into your bank. what i would do is tie these batteries in pairs and pull from the cross corners with all the cable as long as the longest up to a central main busbar. then from the bus to the inverter. you want to sink and source all your power from that bus. you can pick up some real nice 200amp rotor switches for the strings of batteries coming up for less than five bucks a pop. that will end any battery balance issues and give you great control and monitoring abilities. check my gallery photos to get a visual of what i'm saying. also a good starting place for sizing your bus is a minumim one square inch of 1/4 bus plate (cda110) for every 80amps crossing it. fifty bucks will get you a 1/4 x 2 1/2 x 12 inch blank. bigger is better and you will want a good size to land all those big lugs. hope this helps.. please wait for some other comments from more expierenced re folks before ripping your system apart on just my advice. i'm experienced in power systems but still a newcomer to renewable energy.
all the best, dave