Svenska IF-båtförbundets forum

Hello to all. I am new to the site but compliments for the quality as very helpful for Marieholm users. I have a technical question (my apologies if already posted and answered) . My martieholm came equipped with 2 batteries but no coupler. I decided to put a coupler M series ( 1, 2 and both). However the present wiring may indicate that there is a voltage regulator in the alternator. In the attached photo, the the black positive wire in the bottom goes to battery one. the brown wire positive on the red cover of the alternator goes to battery two with a fuse in between. The coupler would require one main positive from the charger to the BOTH position, and one positive to battery one and another to battery two. Could I just disconnect the brown wire without risking overloading the alternator ? A local installer said that it would not. The reason I am adding a coupler is that with the present set up I cannot use the service battery for starting the engine . Also ... can I then add a voltage regulator such as Cyrux or similar ? Many thanks for any guidance.

Any reply ... magic lantern :) ?

Hello again. and help on this topic please . many thanks.

I am sorry to see that you have not recived any answer to you question. I suspect that this is because very few owners of International Folkboats (or IF-boatas as they are called here in Sweden) have inboard engines in ther boats, and threrfore there are very few, if any, on this forum that have any knowlede pertinent to your question.

On the other hand, your question is not, as far as I can tell, specific to IF-boats, but instead relevant to this specific enginge (which to my untrained eyes looks like a Volvo Penta of some kind).

I think you have better odds for reciveing an answer if you post your question on a site where there are more people knowledgable on inobard engines and the electricity issues related to them. In Sweden there is a good site for these questions called saileguide.com, but unfortunately that is a Swedish only site. I hope you can find an English laguage equivalent site somewhere.

Dear Roger,
The shop manuals for the Volvo Penta engines are found amongst the hidden documents only available for members of the Swedish IF-boat Association. As you are such a member of the association please log in as per instructions in the personal message, recently addressed to you.

Thanks much Maja. You are right this is a volvo penta MD5A engine. I love this engine and I am pampering it ;) My only problem is accessing reference resource material as there is very little english based material to help with the engine . Thanks again and best wishes for xmas and the new year. Cheers. R

Looking in the documentation for the Volvo Penta marine diesel engines, it seems than the only type equipped with 2 batteries as standard is the MD2B version. However, in the manual for the MD5A it is indicated that your additoinal battery is extra equipment, but it is poorly explaned how this is connected to the boat´s electrical system.

Maybe you can have a look in the different electric schematics in the manuals to figure out what is valid for your engine? For Swedish text I can be helpful.

In the manual for the MD5A it is also advised, that an external start battery may be used for emergency start and it has to be connected parallell, i.e. plus to plus and minus to minus.