OP
OP
ranger58sb
Guru
Chris,
You have some really good advice above. I have read the CruiserForum thread a few months ago and my take is that unless cost is no object it will NEVER be cost effective in the next 10 years.
Why, because it also entails changing so much of your electrical system.
Yep, have come to agree. Didn't take long, either.That long thread on CF hurt my head!
Which leads me to another issue, as I reread your OP, I did not realize you were wanting to keep two different battery systems on board. That solution would significantly increase your cost and as others have mentioned, brings far more risks than benefits.
Well, it wouldn't have been that I wanted to have two systems; just that only one of the two banks is coming up toward replace time...
Last year, I like you, wanted, needed, to decrease battery charging time to make it nicer to anchor more often and longer. Thus my reading of the CF thread.
My initial solution was to add a second alternator, though at the same time, I changed my fridge/freezer from one that used 18 amps per hour to one that used 5 amps. I also added 440 watts of solar power.
Lo and behold, all of a sudden I didn't need the second alternator. 24 hours on the hook meant -150 amp-hrs; not -450 as needed previously, thus my gen time became two hours, not 8
Sounds like good changes. We already have efficient fridges (came with the boat), but don't really have room for much solar. Not yet ready to think about taking that one yet... although maybe in future it could happen. Depending on usable space on our hardtop...
You seem set in trying to cobble together something, yet want to try something new. I think you would be far better served to rethink your plan entirely.
Well, not exactly
What is your daily, 24 hr, use in amp-hours?
Can't remember, off-hand, but I posted it for somebody else in another thread a while back. Think that was on TF... It's within our current capacity, although I usually have to turn off our bridge electronics while at anchor to be within a comfortable margin. And run the genset morning and evening to recharge while we're cooking. Or when we're trolling for long periods on the port engine, I've had to use the parallel switch to restart starboard. It happens, this starboard bank I'm planning to replace/upgrade is the same one that runs our electronics.
Why not make one large house bank? and add a starter battery.
One large bank will be much easier to deal then having two banks being charged at different rates.
Falls into the same category of "too much other stuff" to deal with. This particular manufacturer has been cranking systems like ours out for donkey's, largely aimed at a typical powerboat market: marina hoppers. Having the two separate house banks hasn't really been too big an issue, actually; consider that I also have two separate houses.
Good point about the separate rates, though. My research on chargers, and discussions with our current charger manufacturer, leads me to believe that's not too big a deal, though, at least when staying within the same or similar basic chemistry. That came up first when I wanted to start the transition from FLA to AGM... but didn't want to toss out a perfectly good port bank, and I didn't want to buy 7 batteries all at once. In an overall system that also has a third bank with a relatively tiny genset start battery. Charger guys said no problem; the charger will only send what's demanded to any of the 3x banks.
Two banks as you envision simply can not be as efficient as one bank.
I think that's likely to be mathematically (physics-ly?) correct, but I think in this case the difference isn't going to be enough to worry me too much. I do appreciate the critique, though, very much.
Good Luck
Very good post, Richard, thanks, I appreciate it. Thought easier to follow imbedded responses....
-Chris
Last edited:
