Even 5 is pretty short. The panels are rated 25yrs plus. Properly cared for batteries (even lead) can last 10 yrs... nickel/iron can last much longer. Makes the charger sound like the weak link.
Kaiwiki McCoy wrote:i'm piecing together my power system (Solar PV with microhydro one day down the line) as i get the funds/find the deals. For a long time i've been wary of the newer type of charge controlers (Maximum Power Point Trackers), because 1) they are much more expensive 2) they have shorter warranties in general (2 years vs 5).
Recently thou, as i've been researching more, it seems like a MPPT makes a lot of sense. Being able to use 24v panels in a 12v system is FANTASTIC, and being able to wire in series for boosted voltage is also great. 24v panels are about 1/2 the price of 12v panels per watt.
60 amp MPPT controller - $500
2 240 watt 24v panels - $980
60 amp PVM controller - $200
4 120 watt 12v panels - $1600
2 240w 24v panels in series to produce 48v can run through the same wire as a single 120w 12v panel - so that's 1/4 panel wiring cost right there, not to mention simplified installation.
Kaiwiki McCoy wrote:
as far as i know, most (modern) panels have build-in blocking diodes that circumvent the problem of older panels re: shading. Without the blocking diode, a little shading on one cell would essentially shut down the entire panel, and any other panels connected in series with it. modern panels use a blocking diode that isolates the shaded cells and maintains the performs of the rest of the cells. i hadn't heard about the shading diffrences between 12v and 24v...just keep them unshaded, no problems.
i won't attempt to build a MPPT controller, and i'm pretty sure anyone short of an electrical engineer would spend more time and money trying to build one that just buying a warrantied version.