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I hauled my boat out for a number of reasons recently so starting a refit period. Looking at adding some battery capacity. Currently, the boat has a Group 34 for starting and a Group 31 for the house bank (Both AGM). The battery box that was present didn't allow me to just turn the battery and add another one so I want to build a new box for two Group 31 batteries. The batteries are located under each quarterberth. While thinking about the battery box, I thought of possibly adding a larger box under the other quarterberth and having 4 Group 31s and may move the starting battery elsewhere.
If I add more batteries under the port side quarterberth, I'd have to first remove and patch a thru-hull, which is planned anyway since the removal of the old head in place of an Airhead.
</IMG>
Click for larger image.
With the possible increase of battery power, and on opposite sides of the boat, I'm trying to think of likely ways to wire things together.
On the left side of the picture below, I have each battery bank hooked up to a switch where one side could be used or both. With that, the starting battery would be relocated, but still wired in. Looking to see if this could work in keeping the starting battery and house bank charged using the alternator when the engine is running. Another idea I have is to isolate the starting battery with its own charging method so the alternator only charges the house bank. If the starting battery is wired in with the rest of the system, would a switch be required or recommended to prevent it from being over charged when the alternator is charging the house bank?
On the right side of the picture, it's wired pretty much as it is now with the house bank on one side of the switch and the starting battery on the other.
</IMG>
Click for larger image.
I wanted to see what recommendations others say about these options and what considerations should be taken into account.
One consideration I already have is the likelihood of replacing the alternator. The engine is a Yanmar 2GM and I believe the alternator is original, so maybe 35Amp. (Haven't seen anything on it yet to say what its rating is) I looked into alternators and those things are pretty expensive. I'm thinking maybe a 100Amp or so would be good.
Anything else?
If I add more batteries under the port side quarterberth, I'd have to first remove and patch a thru-hull, which is planned anyway since the removal of the old head in place of an Airhead.
</IMG>Click for larger image.
With the possible increase of battery power, and on opposite sides of the boat, I'm trying to think of likely ways to wire things together.
On the left side of the picture below, I have each battery bank hooked up to a switch where one side could be used or both. With that, the starting battery would be relocated, but still wired in. Looking to see if this could work in keeping the starting battery and house bank charged using the alternator when the engine is running. Another idea I have is to isolate the starting battery with its own charging method so the alternator only charges the house bank. If the starting battery is wired in with the rest of the system, would a switch be required or recommended to prevent it from being over charged when the alternator is charging the house bank?
On the right side of the picture, it's wired pretty much as it is now with the house bank on one side of the switch and the starting battery on the other.
</IMG>Click for larger image.
I wanted to see what recommendations others say about these options and what considerations should be taken into account.
One consideration I already have is the likelihood of replacing the alternator. The engine is a Yanmar 2GM and I believe the alternator is original, so maybe 35Amp. (Haven't seen anything on it yet to say what its rating is) I looked into alternators and those things are pretty expensive. I'm thinking maybe a 100Amp or so would be good.
Anything else?
