I have a 1984 Tartan 3000 with two group 27 batteries. I installed a Xantrex Trucharge 20 battery charger and now I am thinking of what else I should be doing to upgrade the system. I have had several thoughts and I wonder how to priortize them. I don't have refridgeration but I did install radar, autopilot and a chartplotter this year. I intend on mostly day sailing with a trip from Lake Champlain to LI Sound next Spring for some coastal cruising, overnights are a definate possibility.
Some of the questions I have:
1. Should I install a starting battery, and if so any installation advice, and what type of battery. (I believe my battery charger can charge only one type of battery at a time)
2. How do I monitor the charge in the batteries when not on shore power?
3. Should I buy a small gas generator or can I rely on the diesel engine to charge the batteries.
4. Wind generators and solar panels?
So many choices, you can spend a fortune, how do you get what you need for the least cost?
Thanks for your thoughts.
You've already made a good upgrade by adding the TrueCharge. I agree, your current battery bank is a bit on the small size, but not desperately so for how/where you plan to sail. My approach to upgrades like this is to replace components as they fail or reach the end of their useful life, rather than throwing away equipment that still works fine. This is what I'd do in your shoes, in this order:
1) Swap your Group 27 batteries for Group 31s, preferably AGMs. The 31s fit in the same battery box as the 27s, but you'll immediately have 25-35 more reserve ah. But I wouldn't do that until the Group 27s began showing signs of anemia. OR, explore the possibility of even larger batteries if space permits, but be mindful of weight and trim issues.
2) Upgrade your alternator to a higher output Balmar or equivalent with smart external regulator (e.g., MC-612) and temperature sensing. Again, I would wait until the alternator reached the end of its useful life (if it's the original alternator, I wouldn't feel too bad about doing it with the battery upgrade).
3) Add a group 24 starting battery (same kind as house bank, i.e. AGM, Gell, or Wet).
The reason for doing #3 last is so that you have adequate alternator output to charge the larger battery bank.