Critique proposed solar battery upgrade

BFL13 wrote:
I don't think you need to change anything just now. IMO wait till the Trojans get weaker so they don't do the job anymore, and then replace all four. I doubt you need six except in winter maybe when there is no solar.

I get the same numbers as you and don't have any problem with them. I use a big inverter and get about 0.6 drop with microwave size loads. The drop is the same no matter what voltage you start with.

The object is to stay above 50% with no loads (but you can go lower at times) which is 12.1 with Trojans. That means I can be at 12.1 and that morning still run the kettle or the toaster, when the inverter will draw the batts down to 12.1 minus 0.6 = 11.5 No problem at all. Later that day, after gen hours start, it is time to do a recharge to stay above 12.1.

Note -I have a MSW inverter so it does not draw as many amps when running the microwave as a PSW would, so your 11.4 etc is normal- pulling higher amps that's all.

Actually it doesn't matter what it gets down to under load except for the inverter alarm (mine is at 11 v and it quits at 10.5v but some inverters have different settings)

Six batteries with solar are more likely to not get full in the available daylight, so you get sulfation. Better to have four and get them all right full. EG, 2oldman on here, posted a while ago that he reduced his bank from six to four because of that.

I had six batts in the bank for winter, which was fine doing 50-90s for a few days then go home to do a full recharge, but in the summer on solar I had that problem getting them all full and reduced to four, so they would have a chance to get full on the good days.

I like the idea of moving to 12v batteries when I do the swap. What wattage do you have on your solar array? I was thinking of 1000 watts to make sure I could top up reliably every day (or use the inverter generator when needed).