Which controller?

[jpkelly]

Have recently hooked up twin 35 watt panels in parallel. (sailboat arrangement)
Arrangement is producing about 4 amps, in parallel. I have hooked up one controller (older model-Morningstar with single red light) to one panel but assume that the controller is working with both panels since they are in parallel.
I want to upgrade controller since arrangement is left un attended to trickle charge my 3 Gp 31 AGM batts (110 am/hr each), and am concerned about controller failure.

I am assuming that I don't need diodes since this limited arrangement (70watts) will never over charge batteries, and I also assume that new controller can be rated at around 10 amps??
Are my assumptions correct? Do I need to have two controllers?? Diodes??

THX.

[Mike90250]

Controllers have specific ratings, the amount of current, or Amps, they can handle. As it's pretty likely 70W / 5 amps is within the limits of most small controllers, you should be ok, if a single red LED is the normal mode for your existing controller. If it's old, nasty looking and has corrosion, then yes, look into a replacement for it.

If you use a controller, you don't need any extra diodes.

Make sure your wires are still good, and corrosion has not eaten away at them. Be sure the replacement wires are the tinned copper stranded type, not plain stranded copper, which corrodes quickly.

But, for 330A of batteries, you need more charge than your 70W of solar.

Here's a vendors link to their Morningstar controllers

http://store.solar-electric.com/mochco.html