Looking To Add Solar Down The Road

BFL13 wrote:
Roy, the T-1275s need to get to at least 14.8 to be almost charged up and need to go into the 15s for the top-up to get SG back to baseline.

If your controller can't go that high, don't try to match it with T-1275s. I found that the Solar30 controller can support T-1275s, perhaps because mine goes a bit higher than set. That means to get 14.8 I set it at 14.3 and if I set it to its max of 15v it goes to 15.5 which is great for the top-up. However they probably all don't have that error built in.

Meanwhile my regular 6s can be set at real 14.8 and then drop to float of 14.4 the rest of the day and they do reach baseline SG, which surprised me. I thought they had to get to mid 15s too, but that was when after doing some 50-90s. Solar is different where they don't get down so low, which may be why they can get by on the high 14s.

You do not need MPPT to run a few 12v panels. You only need MPPT if you buy 24v panels of any size. You just don't get much extra charging for the expense of going MPPT controller. You might save a bit on the panels if you have room for the big panels.

You know all the arguments anyway. :) Just don't get a controller that can only do 14.4 and hope to run batteries that need 14.8-15v or you will not be happy. Read the thread "screwy 31" for lots more on that. He finally got that 31 working right by using high voltage charging.

As another reference point, my Solar30, when set at 15.0, will go to 15.2V 120 watts on input 6.6 amps to the battery, tied in to a T-1275 with 5 feet of 12 gauge 20 amp rated wire.

Very, very happy with the Solar 30, it does all I need it to do.