battery charging

wastwast Registered Users Posts: 41 ✭✭
I have recently added 3 banks of surrette 550 12 volt batteries (batteries are 6 volts each hooked up in series)to my off grid cabin solar system.. 1200 ah at c 20.. my charger is a iota 55 amp charger and I have 3 130 w solar panels.. unfortunately this time of year here where I live the sun isn't much help.. Is this charger capable of keeping my batteries charged. I usually run my generator 5-6 hrs a day in winter when at the cabin. Is this enough to keep batteries fully charged> what voltage should my voltage meter show for fully charged

Comments

  • wellbuiltwellbuilt Solar Expert Posts: 763 ✭✭✭✭

    Good question ,  I use 210 watts of solar to charge 230ah battery @ 12volt and it work good all year , until about NOV 1

     I seem to use around30/ 40% battery capacity now, with low light and less hours of day lite  and cool batterys.

     Ive had snow on my panels for a few day also.

    I use a 30amp 12 volt charger for 3hours a day and it gives me enough power, it mite bring me to 85/90% charged .

    I think 2hrs would replace enough power for every day use with a full charge once a week .

    I start to charge at 30 amps and in 3 hours im charging @ 8 amps  around 14.8 volts resting  voltage  +- I run the voltage to 15 volts for an hour every month .

     6 hours seem like a lot every day.

     I would try 4 hours every day and a long charge every 4/5 days  just guessing  

    Out back  flex power one  with out back 3648 inverter fm80 charge controler  flex net  mate 16 gc215 battery’s 4425 Watts solar .
  • vtmapsvtmaps Solar Expert Posts: 3,741 ✭✭✭✭
    Welcome to the forum,

    If your bank is 1200 ah, then rule of thumb suggests a 5% - 13% charge rate.  5% - 13% of 1200 is 60 - 156 amps.  Your charger is a bit on the low side. 

    Whether or not 5-6 hours of generator time can charge your batteries depends upon how discharged they are. 

    By the way, you mention that you run the generator in the winter... but with only 390 watts of solar panel, you will need to run the generator every day in the summer also. 

    Do you have an hydrometer?  If not, get one, use it, and adjust your charging parameters accordingly.  You have a large investment in batteries and you are likely to ruin them by chronic deficit charging.

    --vtMaps
    4 X 235watt Samsung, Midnite ePanel, Outback VFX3524 FM60 & mate, 4 Interstate L16, trimetric, Honda eu2000i
  • wastwast Registered Users Posts: 41 ✭✭
    vtmaps said:
    Welcome to the forum,

    If your bank is 1200 ah, then rule of thumb suggests a 5% - 13% charge rate.  5% - 13% of 1200 is 60 - 156 amps.  Your charger is a bit on the low side. 

    Whether or not 5-6 hours of generator time can charge your batteries depends upon how discharged they are. 

    By the way, you mention that you run the generator in the winter... but with only 390 watts of solar panel, you will need to run the generator every day in the summer also. 

    Do you have an hydrometer?  If not, get one, use it, and adjust your charging parameters accordingly.  You have a large investment in batteries and you are likely to ruin them by chronic deficit charging.

    --vtMaps

    thks for the input.  I plan on more panels in the future. Whenever generator is running then there is no draw on batteries as I have a automatic transfer switch which lets the generator take over until shut down. Not a lot of draw on system mostly lights and a small refrigerator which has a .6 amp draw. I do have a hydrometer and a volt meter to keep a check on things.. this is a remote cabin. sun not much help here at this time of the year.
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