Introduction and questions about my off grid setup

Hi mcgivor, thanks for the reply.

Agreed on part to full time system. This is kind of a special circumstance, related to covid 19. In Colombia, quarantine measures are quite strict, and are forcing people to stay at all times inside their homes, with only specific exceptions allowed to go out. No kids outside, no elder. This will go on, for now, until the end of this month (for now). Since we live in a relatively small apartment in Bogotá (around 700 sq feet), we chose to come here to the country, since even though the house is smaller (500 sq feet), there's ample space outside to move around, with one kid and two dogs. We are planning to move to the country eventually, but this situation has forced us to come here sooner. We don't have a refrigerator or washing machine right now.

Ths is what we plan on using at La Calera. This is the minimum, and it's close to what the apartment electricity bill tells us. I use power tools, but I am ok with using them off the gas generator, since I work outside most of the time. The figure you got is ideal, how much should one consider over sizing for average? There's no snow, just sunny and rainy seasons. Our panels are about 15 deg, facing south. According to PVWatts, It's the best orientation from january till march, then, the sun moves north. Maybe I could over panel a bit, to try and compensate this situation.


The original batteries were purchased in may-june last year, and have been used sparingly,  during weekends for the last year. I understand, and have read that adding old to new is not ideal, but, I could not justify disposing of the old ones or buying more batteries. The ones I got are the same model. I did a quick voltage check at the end of today, to see how unbalanced they were. There was a .15 volt difference between old an new. Old ones at 13.05, and new ones at 12.9. They were all connected in series, for about two weeks. How serious could this be? For now, I connected the old system to the new batteries (parallel 12v) to try and get a full charge, before reconnecting them together again. I checked my cabling, and 1 of the leads is maybe 50% longer than the others. I'll try and correct this. I have no way of disconnecting and charging batteries separately, without getting the house offline. Nor do I have a separate charger. I'll try and get them as close voltage wise, before re connecting them in series, tomorrow, or the day after, depending on weather. Getting hardware right now is close to impossible, given the situation.

I did not take into account inverter inefficiencies... Reading the manual, it says it is around 85% I've opted for turning it off after 9-10 pm, and back on in the morning, for now. It's an off brand inverter, unfortunately no info on the internet, but it's what I have for now, besides the original system. (renogy rover 40 amp + no name inverter) I can scan the spec sheet if needed.

One option I can think of, to apply, using existing hardware, is to create a secondary system. The main 48 v can be used for "heavy" loads, like the refrigerator, and the washing machine, with the existing 1000w power array, (and turn on the inverter auto on feature, so it is only used when needed), and create a secondary 24v system, with my trusty rover, for the rest of the house. That system could be around 600 watt/ 150ah at 24v.  I would need a new inverter, but can probably get away with a simpler 1500 watt tsw inverter. Some extra cabling needed.

hi Dave and Jim. Thanks for the replies.

An update on our current situation. We've been at our house for about 6 weeks, without issues. I reverted back to the previous solar system, at 12v, with the renogy cc 600w of solar, and 4 batt in parallel. Not ideal, but since getting anything now, other than groceries is impossible, it will have to do. I'll check individual voltages next week, but from what I understand, parallel will keep batteries balanced. I wired the batteries using the scheme found elsewhere in this forum, that supposedly evens out the load. But with our modest needs, we've had no issues. April and May are the worse months solar wise in our location and panel orientation.

The first upgrades after everything settles will be a 24v inverter and better cabling (I'll probably get a crimper to make my batt cables, current ones are soldered #4awg). This way I'll run the current system with 900 watt of solar (3s3p). I agree with getting better name brand equipment. The inverter charger was a mistake, but I'll try and give it some better use in an aux system, it's not very efficient, plus it has very loud fans.

 I will create an aux system for my fridge and washing machine, dimensioned accordingly. I will measure power consumption of my washing machine once I can go back to the city. It is a very efficient front loader, direct drive Samsung unit, and I do plan on running it during the day only, with some kind of timed switch.  This will probably be a 3600 wh battery with 400 watt solar.

Reading elsewhere, our power consumption is about 1\10th of the average American home. our climate is very even through the year, no heating or cooling loads, plus no microwave or TV, so that may explain. Our power bill back at the apartment shows an average of 63kw\month.