I added a second deep cycle battery to my boat. I am out on some windy long days, especially when fishing tournaments, and have had my battery run down at inconvenient times. I brought my boat to my boat mechanic and he added two identical deep cycle batteries (31 series), as my original 12v deep cycle was getting old. Everything works fine. Everything is running, however, my on board charger which is also brand new (Minn Kota 330) only shows the second bank as half charged and it has been going a7 hours. Bank 1 (starting battery) is full, bank 3 (2nd deep cycle) is full, but the 2nd bank )1st deep cycle) is half full. I switched the terminal ends so that the 1st deep cycle was on bank three and it showed half so it is the battery from what I can tell. I took off the jumper wire and started charging them and it started charging faster. It got up 75 percent complete so the battery is taking charge but when I put the jumper wire back on it slows down on the charge or is not charging (can’t tell). The light on the charger show that it is charging. I have two questions:
1st – Should I charge the batteries with the jumper cable disconnected? If so, do I need to remove both negative and positive jumper wires or can I remove just one negative and leave one negative jumper wired attached and both positive jumper wires attached?
2nd – what is the order of putting the jumper wires on when they are removed completely. I don’t want to short anything and also dont want to accidently touch a negative lead and positive lead together that are attached to the other batter? I have heard people say put on both negative first and then put on both positive first and then on removal remove both positive first, then both negative. However, I have heard people say put both positive on first, then both negative on. Then for removal you remove both negative first and then both positive. Which way is correct? Never really had to worry about this when just running the one battery.
attached is a rough picture on what my batteries look like.
Attachments:
parallel-battery.png
