TalkBaja.com » Baja Mexico Forums » Off-Grid / Solar, Wind or Generator?

Originally Posted by BajaGringo

It sounds like you and I are in the same boat, both needing a couple more panels. I see a lot of folks recommending to me to keep my ratio of panels to batteries at a minimum of 5% but preferably 10% in terms of amps charge rate:total 20amphr capacity. I am looking to add another kW and am shopping panels right now.

They tell me that if your loads are light and very few cloudy days you can usually get away with 5% but 10% seems to be a number that most suggest to get the batteries up to bulk quickly and allowed to float the rst of the day which they say will extend their life supposedly.

Might not be a bad idea to rewire your setup to 24v and get a new inverter unless you are running 12v loads. Used inverters sell pretty good down here...

I started my original system when 12 volts was about all there was. At the time, I never imagined solar technology would advance as much as it has. When we built the utility room, I pre-installed all the heavy gauge wire (which I bought long before the prices skyrocketed), and other accessories needed to expand my 12volt system when I built the main house, so it's really not that much of a disadvantage to be 12 volts at this point, other than I could have gotten away with 2 charge controllers at 24 volts, where I'll need a total of 3 at 12 volts. Still, an extra charge controller was much less expensive, and much less hassle than buying and installing two new 24 volt inverters. And... I do have a lot of 12volt lighting around the exterior and garden areas.

My setup is designed for Outback inverters. Any other brand won't fit, and I would need to buy two if I increased the batt voltage. They would be difficult to find down here. Two new inverters would run about $4000. Plus... if I upgraded the batteries to 24 volts, I would need to go back and re-wire the panels to 48 volts as the charge controllers I have need the panel voltage to be higher than the battery voltage. That would require about another three or four hundred bucks in MC4 connectors and a lot of work pulling and re-installing wire through the conduit runs. I don't think I have that much energy

As I expanded and bought new MPPT charge controllers, I did upgrade to 24 volt panels though. I re-wired my original bank of 12 volt panels series/parallel to 24volts. I'll eventually replace the 12 volt panels and throw them on my RV.

Since everything is working fine the way it is, and I already have the heavy gauge wire installed, I've decided it's way too much cost and work to change to 24 volts. At this point, I don't think the advantage outweighs the cost and effort to make the change.

Yes, I do need more panels though. I have an additional bank of 5 panels I'm in the process of installing. I packed that project up today though, as it's been well over 100 degrees on my roof. The additional panels are going to have to wait until it cools down a bit. Today I'm not doing much more than sitting under the ceiling fan posting on TalkBaja. I think I need to go jump into the ocean now .

Makes sense to me Wooo. Now if we could just figure out a way to get some kind of efficient heat exchanger that we could circulate on your roof...

Originally Posted by BajaGringo

I have had a few from online who I met in person who seemed genuinely disappointed to discover that was not really me. Maybe I should just change my look!!!

So that's just a younger you and you're more gray and wrinkled now?

Nah, I never looked that good even when I was younger...