Onboard charger problem???

I went to take the boat out the other day and the cranking battery was dead even though the green fully charged light was on. When I unhooked the battery the green light stayed on (I assume it would normally turn red when it is not hooked up). Does this sound like a charger problem or something else?. Thanks.

Which charger do you have?

Here is a photo.

Attachments:

1. 

   IMG_1121.jpg
   

Do u have another battery to test it with? My gut says it’s a bad battery simply because quite a few chargers will indicate a green light when nothing is connected to it.

I have to keep my charger instructions in my boat cause mine does not have simple green and red…just food for thought if you can find the charger instructions.

Lots of charger will not know the battery is connected if the voltage is to low so it will look like it’s fully charged on the charger. Lots of times if you hook a jump box too the battery while the charger is plugged in it will sense the voltage and start charging the battery.

Thanks guys. You were correct it was just a bad battery.