System thoughts?

[WindyMcsunny]

Good day;

my wife and I have a camp on the north channel of Lake Huron. We recently invested in more panels and more batteries to upgrade from the previous setup.
We now have 8 panels at 300W each
And 16 - 6V- 225Ah batteries tied in series parallel. setup in a 24V system.
I’m running the outback FM80 and outback charge controller.

Our question to the group is can we set this up in a 48V system? Would it make a difference? Are there advantages? What is the best way to wire up the panels?

also; 8 of the batteries last week we’re gummed up with corrosion and we’re cleaned immediately. What could cause this? Overheating? Environment?

curious of the equalizing methods and how often or necessary it is to do such maintenance?

 

[chrisski]

IME experience with the lead acid batteries and cars, I have about 6 months left after I find terminals corroded. Sometimes I notice the Battery acis has leaked out of the caps and gotten to the terminals.

I think going to a 48 volt system and dealing with less current is great, provided your current setup can handle it. That way your wiring does not approach an amp limit as quickly. I don’t like to go past 100 amps on my wiring. I am upgrading from 12 volts to 24 volts, but the two things that stoped me from going to 48 volts were:

1) My SCC would not charge a 48 volt battery bank, so would need to replace.
2) Many of my components were not rated to 48 volts like fuses, or were rated to 48 VDC like busbars. i don’t know what happens when you exceed 48 volts on those busbar s by going to 52 volts for charging, or a little over 60 volts for equalization. So I gave up and went with a 24 volt upgrade I am working on.

Also, paralleling 4 banks of batteries can be difficult. In my signature block there’s a link to a document with some math that shows how to parallel multiple batteries with some math that shows resistance and how doing it different ways can show the first batteries work way hard and the last batteries, hardly at all. It’s not such an issue with 2 batteries for 48 volts, but 4 sets at 24 volts

If you use high wattage items quite a bit, then 48 volts can work out. If you hardly use it at all, I‘m not sure it would be worth the effort. Without an energy audit, hard to tell, but with 16 batteries, I think you probably go high amperage a lot.

 

[WindyMcsunny]

IME experience with the lead acid batteries and cars, I have about 6 months left after I find terminals corroded. Sometimes I notice the Battery acis has leaked out of the caps and gotten to the terminals.

I think going to a 48 volt system and dealing with less current is great, provided your current setup can handle it. That way your wiring does not approach an amp limit as quickly. I don’t like to go past 100 amps on my wiring. I am upgrading from 12 volts to 24 volts, but the two things that stoped me from going to 48 volts were:

1) My SCC would not charge a 48 volt battery bank, so would need to replace.
2) Many of my components were not rated to 48 volts like fuses, or were rated to 48 VDC like busbars. i don’t know what happens when you exceed 48 volts on those busbar s by going to 52 volts for charging, or a little over 60 volts for equalization. So I gave up and went with a 24 volt upgrade I am working on.

Also, paralleling 4 banks of batteries can be difficult. In my signature block there’s a link to a document with some math that shows how to parallel multiple batteries with some math that shows resistance and how doing it different ways can show the first batteries work way hard and the last batteries, hardly at all. It’s not such an issue with 2 batteries for 48 volts, but 4 sets at 24 volts

If you use high wattage items quite a bit, then 48 volts can work out. If you hardly use it at all, I‘m not sure it would be worth the effort. Without an energy audit, hard to tell, but with 16 batteries, I think you probably go high amperage a lot.

In regards to the acid; do you have info on how to maintain and test the levels of the batteries?

 

[chrisski]

I take a hydrometer to the cells And compare it against the chart in the owners manual. I do this fully charged. If there’s a difference between cells in excess of what’s on that battery sheet, I equalize. This is for Floosed Lead Acid, not AGM or Gel.

I’ve only had my batteries a year, and have only had to equalize once. Within an hour they were all reading the same.

Monthly, I try to open up my 8 golf cart batteries and check the water level. I add distilled only.

I’ve never seen any corrosion on my Solar Batteries, but my car batteries, I clean that right away. Paper towels, a wire brush, and baking soda water solution works well.

Not much more you can do.