Ditto to Ghurd's comment: "Throw away the controller as soon as you open the box.
Get a Morningstar SG-4, ~$25. It may save that much in asprine."
I bought a couple of very cheap charge controllers from Northern Tools a couple of years back. I think they were around 25$ a piece (about as much as the much higher quality Morningstar that Ghurd mentions), and each were rated at 7 amps. Anyway, both of them -- after around a year or so -- eventually quit limiting the charge -- which can be dangerous, needless to say. After all, that is what charge controllers are supposed to do, limit the charge.
However, I keep them anyway since the blocking diodes in them still continue to work just fine (no surprise there). This can be very helpful for some projects, such as using pedal power on rare occasions to supplement battery charging. Without some blocking diodes, the power reverses and the pedal generator starts draining the battery when not being used. Using one of these el-cheapo charge controllers to block the reverse current is the perfect solution.
So don't actually throw the controller away, put it somewhere in case one day you may need it for something else less important.
