Sep 1, 2006 10:45 am
Re: Power Inverter Faults, what am I doing wrong?
the theory is correct, at least, but the charge controller is not that sophisticated. when it is sunny, it will put into the battery what it gets from the pv. If you have a load on at the same time, it will draw from the battery to fulfil that load. If the load takes out more than what the pv puts in on a daily basis, you are operating at a net loss; not good. welcome to the basics of system design! If you are using more energy than you are producing, it is not the components' fault, but the system designer's fault. although more storage (bigger battery) can delay the inevitable, making less energy than you use will ultimately create a system that will work intermittently if at all.
james - Alt-E staff
it is important to note that some charge controllers have what is called a low voltage disconnect (LVD) which will disconnect the load before you wreck the battery by drawing it too low. with morningstar controllers, the models containing a low voltage disconnect have "L" in the name for the sunsaver series, and the prostar series has an lvd as a standard feature. A low voltage disconnect can protect your batter from an untimely death, but will not fix bad system design. Incidentally, most inverters (even no frills inexpensive ones) usually have a lvd on them nowadays.