Tom.B
Moderator Emeritus
- Joined
- Jul 30, 2009
- Messages
- 5,839
- Location
- USA
- Vessel Name
- Skinny Dippin'
- Vessel Make
- Navigator 4200 Classic
Hello team!
As my introduction to our new 42’ 2000 Navigator continues, I had a chance to spend some quality time in the bilge to figure out exactly how the factory has wired this wonderful vessel. As was documented in an earlier thread, we have had a total failure of battery #3 and the other two are below 80% of rated... so they are on their last leg too. All of the batteries are currently 8D Ray-O-Vac’s from Batteries Plus (NOT deep-cycles), but will all be replaced. Let me also say that there is quite a bit of space to add multiple batteries and also vertical space. Where the #3 battery sits, there is a deck about 36x12 and where 1 & 2 sit is about 48x12.
Below is the diagram and I will point out a few of the features.
Real pic of switches (I am sitting between engines looking starboard):
Battery location (aft under cockpit, still sitting between engines looking aft)
It’s a fairly ingenious design. As it sits, each battery can be isolated for any task. Meaning, there is no “starter bank” or “house bank” designation. That frees me up to design the new system as-needed.
Charging is not tied to the battery switching. I think that is a good thing.
One thing I see as a problem is that all the alternators are tied to the starter posts. Even the genset.
Another thing I am curious about is that the two engines starters are tied together. How common this is I can’t answer because this is our first twin-engine boat. The engines are, by my standards, large, however, I am not the expert. I don’t know how much juice is needed to crank them over. Maine Sail (the guy from Compass Marine) consistently says that starting smaller sailboat engines is a breeze with a house bank, however, I don’t know if these big Volvo’s fall into that category. The instruction book makes only a couple of references to batteries. One of which says the electrolyte density, but the other says: Battery capacity for a 12V system……… 2x12V connected in parallel. max. 110Ah (total max. 220Ah), so it’s hard to say one way or another exactly what is “required” to start these gals.
Finally, the battery switches are all the way in the bilge. That is good and bad. The good is that making an error while underway is less likely. The bad is that it brings in the out-of-sight-out-of-mind mentality and opens the door to an error when anchored or access during an emergency. That may change in the future, but for now, I will just note it and move on.
Here is what I am considering. Let’s say, for a moment, that I do indeed, need to have a separate starter bank for these motors. Would it make any sense to make one bank a pair of dual purpose 12V batteries (Group 27 in parallel maybe?) specifically for that task? Part of me says yes, but unless I start switching around the switches whenever I start the motors, I would me mixing the starter bank with the other two banks. In a way, that seems pointless. But that does still leave me room for two banks of four 6V golf cart batteries (if sized from Trojan T-105s, although there is room to go with taller batteries with even more amp hours).
Otherwise, if we determine my motors do NOT need dedicated starters, could I not go 100% golf cart on all three banks? I will eventually want to put in a medium-size inverter, so the way I see it, the more the merrier.
I am not afraid to make some major changes, however, considering that this is a fairly good setup, about the only thing I might need to do other than all new batteries and a few lug changes would be to maybe move the alternator feed wires… but to where, I am not sure. Then, maybe next year, throw in some buss bars and move the switches up to the main salon. It’s not a very far move. Just a foot or so above (through the floor) from where they are in the bilge and into a cabinet below the breaker panel. Still, that would be a fairly big task that I am not really ready to tackle.
Look forward to your opinions.
As my introduction to our new 42’ 2000 Navigator continues, I had a chance to spend some quality time in the bilge to figure out exactly how the factory has wired this wonderful vessel. As was documented in an earlier thread, we have had a total failure of battery #3 and the other two are below 80% of rated... so they are on their last leg too. All of the batteries are currently 8D Ray-O-Vac’s from Batteries Plus (NOT deep-cycles), but will all be replaced. Let me also say that there is quite a bit of space to add multiple batteries and also vertical space. Where the #3 battery sits, there is a deck about 36x12 and where 1 & 2 sit is about 48x12.
Below is the diagram and I will point out a few of the features.
Real pic of switches (I am sitting between engines looking starboard):
Battery location (aft under cockpit, still sitting between engines looking aft)
It’s a fairly ingenious design. As it sits, each battery can be isolated for any task. Meaning, there is no “starter bank” or “house bank” designation. That frees me up to design the new system as-needed.
Charging is not tied to the battery switching. I think that is a good thing.
One thing I see as a problem is that all the alternators are tied to the starter posts. Even the genset.
Another thing I am curious about is that the two engines starters are tied together. How common this is I can’t answer because this is our first twin-engine boat. The engines are, by my standards, large, however, I am not the expert. I don’t know how much juice is needed to crank them over. Maine Sail (the guy from Compass Marine) consistently says that starting smaller sailboat engines is a breeze with a house bank, however, I don’t know if these big Volvo’s fall into that category. The instruction book makes only a couple of references to batteries. One of which says the electrolyte density, but the other says: Battery capacity for a 12V system……… 2x12V connected in parallel. max. 110Ah (total max. 220Ah), so it’s hard to say one way or another exactly what is “required” to start these gals.
Finally, the battery switches are all the way in the bilge. That is good and bad. The good is that making an error while underway is less likely. The bad is that it brings in the out-of-sight-out-of-mind mentality and opens the door to an error when anchored or access during an emergency. That may change in the future, but for now, I will just note it and move on.
Here is what I am considering. Let’s say, for a moment, that I do indeed, need to have a separate starter bank for these motors. Would it make any sense to make one bank a pair of dual purpose 12V batteries (Group 27 in parallel maybe?) specifically for that task? Part of me says yes, but unless I start switching around the switches whenever I start the motors, I would me mixing the starter bank with the other two banks. In a way, that seems pointless. But that does still leave me room for two banks of four 6V golf cart batteries (if sized from Trojan T-105s, although there is room to go with taller batteries with even more amp hours).
Otherwise, if we determine my motors do NOT need dedicated starters, could I not go 100% golf cart on all three banks? I will eventually want to put in a medium-size inverter, so the way I see it, the more the merrier.
I am not afraid to make some major changes, however, considering that this is a fairly good setup, about the only thing I might need to do other than all new batteries and a few lug changes would be to maybe move the alternator feed wires… but to where, I am not sure. Then, maybe next year, throw in some buss bars and move the switches up to the main salon. It’s not a very far move. Just a foot or so above (through the floor) from where they are in the bilge and into a cabinet below the breaker panel. Still, that would be a fairly big task that I am not really ready to tackle.
Look forward to your opinions.
