# Solar Maintanace Charge Marine Batteries

Posted by phillb on December 19, 2016, 9:36 am

A friend of mine has a Battery Tender connected to five marine batteries for over winter maintenance
I mentioned solar panel on garage and a battery charge controller for the batteries
Have been going over the web pages of controllers
But there is no mention of series or parallel with the controllers; It just seems single battery connection for one solar controller
Is there a set amp number I should be looking for dealing with solar charge controller, or is there a controller made to handle multiple battery connection to maintain five 12 volt batteries over the winter months

Was thinking just connect 10 Watt Panel, Charge Controller with thermal sensor for batteries, two batteries in series connected to other two in series
Swap the lone fifth ever other two weeks

Thank You

Posted by Martin Eastburn on December 21, 2016, 5:52 am

Suggest you determine the charging voltage & current of flat batteries.
Then make sure the charger can handle that power on the output.
Then determine the input voltage & current to provide that output.
That then determines the array wattage / voltage & current.

Martin

On 12/19/2016 3:36 AM, phillb wrote:

Posted by phillb on December 21, 2016, 12:07 pm
So figure from a flat battery, by flat almost dead?

Posted by Martin Eastburn on December 22, 2016, 5:43 am
If the battery is driving a load and there isn't solar to
charge and the battery works for several days without getting
a charge due to the local storm or snow on the array or heavy over cast.

I got less than 4 kWh for 4 days - 2 were in the 1kWh out of my 6.5KWP
array. On good days I'm 20 to 35 KWH per day.  And if off the grid, (I'm
not), I'm running lights, computer and Air controls.  And a monster
fish tank with several pumps, heater, cooler, and fan-pumps.

Therefore at night I draw from the utility and many days as well.
I can make for 50-70 % on really hot summer days and buy 50-30% power
from the grid.

Martin

On 12/21/2016 6:07 AM, phillb wrote:

Posted by phillb on December 24, 2016, 1:02 am
Martin
Thank you for the comparidon
Helps with future ideas n wishes

Phill