You'd think I would know this by now... I'm spending a lot more time on a mooring ball and on anchor now and getting used to being on solar/battery/generator.
I think my system is doing pretty good. I just upgraded the solar and do get some charging. Yesterday my batteries went from 100% to 85% in a full day's usage. Today I decided to determine how long it will take me to get to 100% charge by using the generator (and solar) and I haven't had much success.
With the generator running
With the inverter switched to the "On" position my batteries depleted at what seems like a normal rate, they don't seem to be charging at all
With the inverter switched to "Charging" the batteries do charge, but only about 1.5% per hour (went from 76% to 77.5%).
At this rate it will take me another 15 hours to go from 77.5% to 100%. Am I looking at this wrong? Is this what others experience as well?
THANK YOU Duane and Bryan!! Between you two we solved at least half of it.
First, my battery voltage settings in the MPPT app for absorption, float, and equalization were way off for my lead acid batteries.
Second, the person that installed my solar wired the negative from the MPPT directly to the battery negative post. This excluded solar from the battery monitoring. I switched the ground wire from the battery to the tail end of the shunt (the end not connected to the battery) and BAM, it all started working. Good catch Duane!
My guess is that since I have a Cerbo GX, it uses the battery monitor and the MPPT to tell the inverter what to do. All three of these are connected on my setup. The interface on the Cerbo Gx never matched what the battery monitor reported and because of this I suspect it wouldn't allow the battery to charge. 70% was really 100%.
Right now my solar is keeping my battery charged to 100% so I'll need to let this deplete to test the generator charging, but I have a good feeling that will work now!
Another follow up. I turned a lot of stuff on last night and this morning the battery was at 71%. I've been charging and it seems that I get about 5% per hour of charge. I know this can be incredibly variable (cloudy day with lots of solar, AC on some, charging my dinghy outboard battery, water heater on, etc.) but just wanted to let everyone know that my problems from yesterday have been solved. Phew! Thanks again for everyone's help.
With a reasonable wattage of solar, for many days in Florida you can replenish overnight losses without need for the generator. You will need the genset to heat domestic water, of course, and run A/C and maybe your microwave.
Batteries, somewhat excluding the new Lithium versions, can take a high current charge only when at their lowest state of charge SOC (better to not get lower than 70% if you can help it with most batteries). Running a genset to get the batteries over 90% SOC is very inefficient since the charger will reduce the current more and more as you get closer to full.
What works well is to run the genset in the morning to make coffee, toast, heat water, and charge the batteries for a bit. If you expect sun all day, you could get to 80% charge and let the solar do the rest. If you expect less solar output, then charge with the genset longer. One advantage of heating water while charging batteries is to keep the genset loaded. In my opinion, it is OK to run lightly loaded when you need to, but better to load it up 50% of more.
You commented about charging at 5% per hour. Since the rate of charge drops asymptotically as you approach full, using a fixed percent rate is never an accurate way to estimate how long it will take.
This should be obvious, too, but running a heavy AC load while the genset is operating is much better than using the inverter to handle the AC load, then later running the genset to replace all the lost battery energy. Each conversion has significant losses.
Finally, best of luck figuring out all there is to living on the hook (or mooring). Feel free to call with questions.
