Electrical System Refit

I finally started a project that has been on my mind since before I even bought Sea Puppy. Moving the battery from starboard to port. The original design (actually the only design from the factory) for the Beneteau F235s has the engine, gas tank, Cockpit locker, holding tank, head, chart table and battery all on starboard.. This gives a normally laden F235 a pronounced list to starboard. When sailing on starboard tack this is like having another crew person hiked out but on port its just the opposite.. This creates a significant difference in speed between port and starboard tacks as well as a little bit of pointing difference.

When I first saw this I thought that moving the battery to port would help. It would take (for the group 27 battery I have) 70lbs from starboard and move it to port. The equivalant of a 140 lb person hiked out on port with no changes made. I measured the compartment under the port settee just forward of the galley and it has plenty of room for the battery (actually it has room for 2 group 27 batterys if needed in cruising mode).

The battery was under the chart table on starboard and is now under the the settee just forward of the galley.
I only have one battery as yet.. but the cables are run for when and if I want a second one. (note: I got the second battery about 2 months later and installed it beside the first one)

I used awg 2 cable for the batteries back to the switch.. I know that this is much heavier than needed for normal sailboat systems but I have a 1000 watt inverter I am installing. ( I had a 400 watt one but it couldn’t handle the load from my drill) Also I plan on experimenting with a trolling motor as a auxilary drive and need the cables to carry at least 30 to 40 amps for that.

Richard had some old cable laying around that he gave me which gave me two runs about 15 feet long and then I was able to buy a 20 foot length of marine grade tinned awg2 cable for 1.26 a foot.. which is a great deal. I ran all the cables together from the new location to the old location where the switch is mounted under the chart table. I also installed two bus bars one for the ground and one for the common positive coming off the switch. These are mounted externally beside the switch and under the chart table. I have to create a shield over them to make sure no one accidently touches both at the same time but the way it is layed out it makes working on the electrical system very easy. Before you had to practically crawl up in the cubby hole behind and under the chart table in the head area. A 5 year old might be able to do it but trust me even a small adult ends up looking like a pretzel to reach it and even then you might not be able to do anything productive once your jammed in there. 🙂

The battery Switch is already a 2 battery switch with 1/2/both/off settings and it is rated to 250 amps.. So I think it can handle everything this system can throw at it. The bus bars can handle 100 and 150 amps respectively.. I will be changing out the 100 amp one for a 150 amp one later so both are the same but for now i will use the smaller one that I had on hand.

The cables are set up so that there is a jumper cable between the negative poles on the batteries and then the yellow cable runs from one of the negative terminals to the ground bus bar. There are two positive (black in color) cables running from each + terminal on the batteries to the 1 and 2 battery poles on the switch respectively. ( actually there is only one battery so there is no jumper between negative terminals and the second positive battery cable is just laying there unconnected) Then there is a awg 2 jumper cable running from the common positive terminal on the switch to the new + bus bar. All the positive and negative cables from the fuse/switch panel run to the easily accessable bus bars now.

Later this week I should have some pictures off all this to show so check back.

ok pictures are now here

Where you see the coiled white bilge pump hose is where the battery used to sit. This is on the starboard side of the boat under the chart table in the head. as you can see the battery switch is still here I just ran some long battery cables to where the battery is now. Using aw2 cable. The two buss bars to the left are a ground buss where the yellow cable connects and above a positive buss that the cable from the common connection on the back of the switch goes to. Mounting them here allows very easy access to wiring stuff in.. I still have to build and install a shield over these.


here is where behind this bulkhead that the cables go under the old battery compartment floor and start across the boat to startboard. the next pictures should document this.


It goes through the aft compartment here


and on starboard into the first aft galley cabinat


Under the stove


Under the sink


and in to the new battery compartment under the port couch


Also here is the new 12volt switch panel layout


This happened a few months later.
Well I took my battery back in monday to west marine and they put a tester on it and then exchanged it out for another battery. They didn’t have any group 27 gells in stock so gave me a group 27 AGM battery. I got 13 dollars in change back as the AGM batterys are cheaper than the Gel batterys now. The GEL was 87 amp hours while the AGM is 92 amp hours.. So I got about a 5 amp hour upgrade. The downside is that AGMS do not last as long as GEL batterys. I will be buying another Group 27 AGM to make a two battery bank on Sea Puppy. This will give me a much larger capacity and also some redundancy.. As I have already installed the cabling and connectors prior when I was rewiring the batterys to be on port instead of starboard it will just be a matter of hooking up the second battery.

Something I have also learned from all this is that a pre-sailing checklist and a post-sailing checklist are needed. I will be putting this list together and working with it for a while this fall before I get it laminated and mounted on sea puppy so that you can check it off with grease pencil.. I will probably also leave a blank space so that repairs that are needed or items that I need to buy can be written down as I think of them.

And just a few days later
Ok I got the second battery and installed it.. I had to create the jumper cable from one negative post to the other battery’s negative post and then connected it all up. So now I have two 92 ah AGM batterys wired to a OFF/1/2/Both switch.. it works well.