I have a 2006 Mainship Trawler twin engine Yanmar. I just installed a dual out put solar controller plus 175 watt panel because I keep my boat on a mooring and some of the parasitic charges keep running down my batteries . I am trying to figure out how to choose the priority batteries to charge. The controller defaults to the position #1 when there is not enough solar to charge both banks. I have three 8d batteries (two outboard of the starboard engine not in parallel as far as I can see)two cut of switches marked port engine and starboard engine. There is also a third cut off in the bilge area that cuts off another battery located outboard of the port engine. There is a separate battery for the windlass and the generator aft with its own cut off switch as well. When I cut off switch to port battery both engines still start. When I cut off port or starboard switches corresponding engine won’t start. When I remove cable from one of starboard batteries with both port and starboard switches in the on position there is not enough power to crank either engine but they are not visibly in parallel. This is confusing me , I don’t know what “house battery”is because when I switch off the single battery outboard of port engine with the switch in the bilge I still have house power to some items(not fridge). The owners manual is of no help. Does anyone know if this is the original configuration and have a schematic? In the mean time I have connected the priority charge to the two batteries that seem to be somewhere parallel that start the engines and do run a couple of bilge pumps.
Battery question
- Thread starter Roger L
- Start date
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Roger
I can't swear to the 2006 or anything PO might have modified.
My 2008 34HT from factory had similar pair of 8 Ds on Stbd that were a combined engine (mine single) start and house. Single 8D to port ran bow & stern thrusters only.
I have made many mods and documented charging system mods in the project section of my Bacchus website linked below and in a thread in the TF Marlow-Mainship section.
I have since moved my eng start to the port thruster batty for a much shorter run and to leave a pure house bank.
A also changed my gen on/off sw to a 1-2-all and added a jumper to my house which let's me charge the gen batty if needed (normally only charged by the gen alt) or to boost start in an emergency.
Yours sounds similar but I'm surprised the fridge has been powered by the port batty as that batty on mine does not feed any part of the 12V distribution panel. Thrusters each have separate 500A fuses and on/off switches in the ER. I did not fuse eng start when I moved it.
No real helpful MS schematic info I'm aware of and I just had to start tracing, checking continuity and documenting what I found and them modified.
Hope that helps.
I can't swear to the 2006 or anything PO might have modified.
My 2008 34HT from factory had similar pair of 8 Ds on Stbd that were a combined engine (mine single) start and house. Single 8D to port ran bow & stern thrusters only.
I have made many mods and documented charging system mods in the project section of my Bacchus website linked below and in a thread in the TF Marlow-Mainship section.
I have since moved my eng start to the port thruster batty for a much shorter run and to leave a pure house bank.
A also changed my gen on/off sw to a 1-2-all and added a jumper to my house which let's me charge the gen batty if needed (normally only charged by the gen alt) or to boost start in an emergency.
Yours sounds similar but I'm surprised the fridge has been powered by the port batty as that batty on mine does not feed any part of the 12V distribution panel. Thrusters each have separate 500A fuses and on/off switches in the ER. I did not fuse eng start when I moved it.
No real helpful MS schematic info I'm aware of and I just had to start tracing, checking continuity and documenting what I found and them modified.
Hope that helps.
I do have a bow thruster. I did not think to see if the port battery is for the thruster. I will confirm. I will double check to see the fridge actually is powered down when I cut off that battery. This all makes sense the port battery is fused. My concern is that one 8d battery alone will not start the engines. Perhaps I have battery issues on one of the two starboard batteries or both. At the batteries only the negative runs between the two batteries ,I would have assumed they would be in parallel and the positive would be going to the second battery I put the solar input directly to one battery and did not jump this to the other battery because they appear to be independent but I don’t think they are. This is where I am befuddled
Do your eng start battys on stbd side have 1-2-all-off switches on each?
My single had a switch that selected between the batty's on the stbd side.
If you go into the ER and remove the fiberglass cowl where the air intake is it will give you access to the back side of the electrical panels and will make tracing out easier. You should be able to follow the lg cables from the stbd battys and learn how they are connected.
I will bet each is wired to a sw and then to each engine a.lowing you to start from either and combine or separate or combine for house but it needs checking.
One 8D should be more than enough to start your engine(s) if it is in good shape and fully charged. when I had start on my house combined if I only had one 8D selected there was no problem starting but at sometimes my electronics didn't like the surge & V drop. no issues when I had them both combined. That was part of my reasoning to move start to thruster bank and have it completely isolated from the house, in case house was run low and also to avoid any issues with electronics flinching. I once lost all custom screens etc on my Raymarine GPS / MFD when I started my engine on a single batty and house was also only on that batty.
I will look for a pic of mine and post it.
Roger - here is my old (OEM) start / house selector panel. As you see the battys are marked Port & Stbd but they are really both on the Stbd side and I have labeled them #1 & #2 as the only Port batty is for thrusters (and now my eng start)
How good are you at tracing / checking continuity with a DVM?
That was how I really learned how my battys were wired. It is not hard but it does take some time and discipline going through it. The good news is it doesn't have to be all at once - you can do it a section at a time and learn as you go.
My single had a switch that selected between the batty's on the stbd side.
If you go into the ER and remove the fiberglass cowl where the air intake is it will give you access to the back side of the electrical panels and will make tracing out easier. You should be able to follow the lg cables from the stbd battys and learn how they are connected.
I will bet each is wired to a sw and then to each engine a.lowing you to start from either and combine or separate or combine for house but it needs checking.
One 8D should be more than enough to start your engine(s) if it is in good shape and fully charged. when I had start on my house combined if I only had one 8D selected there was no problem starting but at sometimes my electronics didn't like the surge & V drop. no issues when I had them both combined. That was part of my reasoning to move start to thruster bank and have it completely isolated from the house, in case house was run low and also to avoid any issues with electronics flinching. I once lost all custom screens etc on my Raymarine GPS / MFD when I started my engine on a single batty and house was also only on that batty.
I will look for a pic of mine and post it.
Roger - here is my old (OEM) start / house selector panel. As you see the battys are marked Port & Stbd but they are really both on the Stbd side and I have labeled them #1 & #2 as the only Port batty is for thrusters (and now my eng start)
How good are you at tracing / checking continuity with a DVM?
That was how I really learned how my battys were wired. It is not hard but it does take some time and discipline going through it. The good news is it doesn't have to be all at once - you can do it a section at a time and learn as you go.
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My battery switches are just On/Off . Removing the cowling is a great idea and I do have some experience tracking electrical. This is my first season with this boat and spent a great part of the season fixing many small problems I came across on my trip down from Maine. I have learned a lot about the boat just from these issues. I will try and do a systematic check and figure this out. Thanks for your help . I will update as I find things out.
garmstro55
Senior Member
Which Mainship are were talking about? I have the schematics for the 400 Trawler and on my 400, that is not how my batteries are set up.
