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jeff cote here with pacific yacht  systems we've got a boater with solar  panels  asking about the minimum charge rate for  batteries and how would solar meet that  minimum charge rate  it's  a problem it's a  conundrum you know  with solar we don't necessarily do what  we want we do what we can  right all of us or many of us  want or would want solar panels to do  everything on our boat  and bulk charging your batteries with  solar panel  is going to be a really maybe that's a  little bit stretching  right because remember solar panels are  not able to deliver  a lot of energy over a short period of  time they give you some energy over a  long  period of time so when you factor that  in  it's going to be really hard to size a  sol's solar array on a boat to be  bulk charging so for example in this  instance we've got a 440 amp hour  battery bank that's probably four golf  cart batteries  okay so we've got a 400 hour battery  bank and i  constantly emphasize that you need a  minimum of 10 percent charge as a charge  rate  so that would be 40 amps well 40 amps on  a solar array is going to be huge it  might be uh  at 12 volts it might be probably seven  800  probably or more watts of solar panels  and that's when it's really sunny  so you're rarely going to be able to get  that sort of output from a  solar array with solar you do what you  can  and generally what's going to be good is  the battery bank might not go too low  you're probably not going to go from 100  down to 50 overnight you might only go  from 100  because when by time you go to bed the  batteries are near full  you bring them down the next morning and  as the sun starts shining  you might only bring your batteries down  to 80 or 85 percent  or 90 overnight and if that's the case  then the bulk minimum charging  requirement of 10  won't apply right because you're  actually in the absorption  stage of your battery charging so first  solar you do what you can  and if you can't do it that's okay  thanks for asking