hi im really sorry that im being this kind of person but i dont exactly get many chances to buy up at the electronics store, so i will just describe what i need, and if you know what it is called ill look at the relevant wiki page
I have a really nice 12 VDC to 240 AC inverter that works really well when supplied 12 VDC from my lead acid bats, but in incorporating solar panels and having a number of 12 VDC cells, I'm finding that it is very easy for them to have too much voltage, which flips the fault switch on the inverter. So im guessing a voltage regulator would be a good guess