On our shakedown cruise of the 4788 a few weeks ago we noticed that the port side starting battery was totally dead, and would not take a charge, but this had not been noticed when we purchased it because there is a crossover switch from the house batteries to the starting batteries. That crossover switch was on, and we had not noticed that during the survey or sea trial. Typically the crossover switch from the house batteries to the starting battery is only to be used briefly, effectively for a jump start, otherwise it runs down the house batteries, which may explain why they were dead also.

After our experience with the getting the dinghy to run, I know that old battery cables on a boat can be in pretty bad shape, and the red and black wires going to the starting batteries looked seriously bad, so we decided to replace them while replacing the starting batteries.

It had been recommended that instead of replacing the 12v 4D staring battery with another 4D battery, instead that we replace it with 2 group 31 batteries. We picked up 2 Group 31 batteries from West Marine, ordered some battery boxes from Amazon, and picked up some more 2/0 battery cables. Fortunately from our house battery bank work I already had the crimping tool, and most of the ends that I needed to put on the cables. I had to buy some addition cable ends with a 1/2 in hole to replace the wires from the starting battery.

Here is what the 4D battery looked like when we pulled it out.

And after removing the black wire from the old battery to the engine block I cut it open to see if it was really worth replacing, and anytime there is more black than copper in your wire that is a bad sign.

Then with help from the boys we installed the new battery boxes, made custom cabling for the new pair of batteries, and replaced the wires going from the batteries.

The engine started beautifully. Next on to the starboard side starting batteries, and the generator starting battery.