Space for another battery?

[timturner]

In the 2 cabin version of the 36i, in the storage area behind the shower, there is a space below the floor just inside the door. I am considering putting the engine battery here, and devoting all three batteries underneath the bunk, to service batteries. Has anyone tried this, if so how did you get on with the wiring, etc.?

[Trevor]

Hi Timturner,

I guess the battery could be put in fibre glass a battery box and then tied down. I think it would be easy enough to parallel the old start battery with the other house batteries. It would then require an extended black earth cable and an extended red positive cable to the isolation switches. Because the distance is extended the cable needs to be pretty heavy gauge.

This sounds like a good idea to me and I might try it myself before we go on a 3 week cruise in November. ;D

Thanks for the great idea.

Trevor

[jamestown]

Just for info, on the 2-cabin 39i, the service batteries are all under the floor in the storage area, and the one engine battery is under the bunk on the starboard aft. So yes the positive and negative leads go to the isolator on the other side of the boat without trouble. It actually isn't very far since the batteries are just on the other side of the bulkhead and the isolator is also very near the bulkhead. There isn't all that much space between them in a straight line.

Steve

[Trevor]

Timturner and Steve,

I had a look at my boat today and the space below the floor in the aft port locker is fairly narrow. The space between the aluminium angle protecting the cabling and the support for the back of the opening cover only about 150mm. The smallest start battery I have found has a with of about 175mm so I'm not sure how to get a battery down there.

Can you get thinner batteries or are you modifying the opening?

I would like to do it but do not want to take to the boat with heaps of cutting implements.

Regards,

Trevor

[Trevor]

This is the space I am talking about.



This photo was taken from the shower and shows the space for the battery but in my case it is only 150mm wide. I don't think I can get a battery in there?

Trevor

[MartyB]

Trevor,

You could go with dual starting batteries, ie two smaller ones that together equal the same CCA that the single one does. Larger diesel trucks etc use this option. I have a smaller battery on my mini track hoe/excavator that would fit in that area, BUT, you would probably need at least two to start up your motor, depending upon the size of the motor. I have a 16HP 3 cyl Yanmar of about 750CC IIRC the size. A bit smaller and easier to turn over than our boat motors.

Optima if they or an equal exist down under, has starting batteries that are 6.8 and 6.9" wide, or about 175-180 mm wide.

It is doable, but you will need to talk to a local battery supplier etc to see what can be done.

marty

[Trevor]

Thanks Marty,

I will have a look around and see what options are available. I wouldn't mind increasing the house capacity if I could get a start battery to fit reasonably in the space.

Regards,

Trevor

[timturner]

Thanks everyone for the contributions, so helpful and factually correct. Trevor, you are right, the aluminium cable protector does not help matters and is difficult to remove. So what I am going to do is to remove the floor support batten, which widens the space to 174mm. There are several batteries that are 170 - 174mm wide so I shall have no trouble getting it in and out. I shall then put in a marine ply floor supported on battens screwed to the heavy plywood sides. Rather than a battery case, I shall put in some battery straps to keep the battery secure. I have to replace the floorsupport batten but I will keep the centre section as a removable piece to allow for the access. This will be a good job now that winter has set in and the boat is out of the water in a superb boatyard beside the River Dart in Totnes, Devon.
I am also fitting a 48w solar panel to keep the three service batteries topped up ( Serenity is on a swinging mooring in the Salcombe Estuary ). Also, thanks to Trevor, my son and I are just getting together the bits and pieces to enable the amp meter - such a useful tip and it seems so mean that Jeanneau did not do it in the first place!!
Thanks again for the useful tips, Tim

[saxofon]

Interesting! I have a SO 37.1 (1995 years model) and have started to look at redesigning the lowest step at the engine to a box instead and have the engine battery here.
Hopefully all required electronics on the engine battery side would fit there as well.
This would mean that I can fit another service battery in the starboard aft cabin where the current engine battery is.
I have also mounted 2x33W solarpanels on each side of the coachroof together with a regulator.
Works wonderfully and I haven't had any shore-connection at all this season.
My three service batteries was in half-descent condition when I bought the boat in may.
After a couple of weeks with solarpower and frequently adjusting the water-level in the batteries (they took quite a lot of water in the beginning) they are now in top condition and haven't required any water adjustment at all. I'm very happy with this installation.

[Trevor]

Hello All,

As we have revisited this thread, I have done the extra battery modification on our SO36i.

It was pretty simple. I cut a section out of the floor support which allowed enough room for the battery to be lowered into the space. I then put two rails either side down near the bottom of the space and put a piece of timber across the gap to support the battery. I bought a battery cradle with plastic hold down screws and fitted the battery.

Two 1.2 metre battery cables allowed the negative to go to the common earth connection on the house batteries. The positive went straight to the battery isolator switch.

The original cable to the start battery isolator switch was paralleled to the other house batteries.

We were away for three weeks and it was great to have that extra house battery capacity. It was a big improvement. ;D

Happy sailing,

Trevor

[timturner]

My goodness Trevor, you don't hang about do you!! Unfortunately, I have had to have a hernia sorted, so my work schedule is running late and now it's Christmas. Very good to read what you have done, if you can, a photo would help. It OK for you guys down under, it has been so cold here, the coldest December for 30 years, working on a boat is no fun right now. Happy Christmas to all, Tim

[Trevor]

Hi Tim,

Yes the extra battery really helped when we were cruising up the coast. I'll try to remember to take a photo when I am back at the boat next.

Regards,

Trevor

[Trevor]

Hello,

Today I remembered to take the photo I was asked for,



This is the start battery installed on the port side in the locker under the floor leaving the three batteries under the bunk for house batteries.

Happy sailing,

Trevor

[timturner]

Only two weeks to "launch day" and most jobs are finished including putting the engine battery in the locker under the floor of the port-side storage area. I know I suggested the possibility last October, but an Englishman needs time!! I am glad others have done this, it works a treat. I have also fitted a flexible solar panel on the coach roof, which on a good sunny day will give about 4 amps - a good steady top up. And finally, I have fitted the shunt and wired it up so we have an amp reading , as suggested by Trevor. Thank you to everyone who has had some input on these matters, it is so helpful.
PS. I also put a cupfull of sunflower oil in the holding tank so as to free up the outlock cock, and it also worked well!!