Tom and Victor, Thanks so much for your timely and informative responses. The house batteries (deep cycle) are separated from the starting battery. The only time they would be connected in parallel would be if I had the battery switch set to "both". The boat's engine can actually be started on the house (#2) setting but this would be undersirable since it consists only of deep cycle batteries and the boat's electronics are connected only to this circuit. I don't want to unnecessarily expose the electronics to voltage or current fluctuations. If I am anchored, I would only have the battery switch set to #2, thereby isolating my starting battery from any current draw.
My quandary is this: I will start the engine on #1 battery (starting) only.and then let it recharge. The starting battery is normally charged before the engine is warmed up. I could then turn my battery switch to "both" which would connnect the house batteries and starting battery in parallel. The alternator could then start charging the house (deep cycle) batteries. Theoretically or at least it should be, the alternator voltage output is higher than that of the batteries. Hence, since the starting battery is charged at this time, most the current would then be directed to the house batteries for charging. For additional protection, however, would it be better to install a dual battery isolator that basically consists of 2 diodes that will not allow current flow from the stronger battery to the weaker battery through the charging circuitry? I am not sure this is necessary or desirable given I can separate the circuits manually by my 4 position switch. ( "off", #1, "both", #2) Most RVs are wired with the dual battery isolator. Any ideas? Tom, as I write I am watching someone ice skate on the lake in front of the house. I envy the warmth of Florida right now. However, I will be spending a week in the Ten Thousand Islands area during the middle of March, so my view will change a lot. Only trouble is, my father-in-law has a house right on the water with a channel that leads all the way out to the Gulf. Sounds good, but he sold his boat two years ago. Makes no sense! Thanks again, J. Black On Feb 27, 4:42 am, flitebuilder <[email protected]> wrote: > JB, > > I have done a lot of research for my 36' SS. It has 4 12 volt systems > and here is what I am going to do. > > 1. Start battery for each engine > 2. Start Battery (smaller) for the generator > 3. House batteries (not sure what batteries yet, will be determined > by remaining budget at end of re-fit. > > The two main engines will be seperated from eachother with cables from > thier respective batteries. There will be a battery combiner switch > between the batteries. This switch will be in the engine > compartment. The supply for the switch will run to a combiner switch > at the helm that will allow you to connect the engine(s) to the house > circuit. If on 1 or 2 then either the port or starboard engine will > be connected to the house batteries for emergency starting purposes. > Normally with everything working properly the engines will be left in > parallel all the time and the switch turned off when not in use. > There will also be plain on / off switches for each engine battery to > turn them off during storage. > > On the house circuit there will be an automatic charging relay that > will automaticlly connect the engine(s) to the house batteries to > charge them. This unit has starting isolation so that when the > engines are starting the relay will not connect the two banks. The > house circuit will also have the ability to be charged froman on-board > battery charger. > > The generator 12V circuit will be completely isolated from the rest of > the boat. I will have jumper cables for emergency puroses though. > > In normal operation you will get to the boat and turn on the two > battery switches for the main engine batteries, switch the 120V system > from shore to gen, and prepare to leave... If there is a problem with > the main engine starting batteries there will be a very fast option to > start from the house circuit. > > For more information you can look on Blue Sea Systems website. they > have some great information on boat wiring. Of course they are > wanting you to buy thier stuff. I do reccomed thier products as I am > very impressed with the way they are engineered. > > I will be posting my boats wiring diagrams soon. I am still working > on them. I am re-engineering the entire system. > > hope this helps, > > Victor --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "UnifliteWorld" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/UnifliteWorld?hl=en -~----------~----~----~----~------~----~------~--~---
