Manatee House Bank Capacity

Well, it seems it's time to replace house bank. T105s (8) making 900ah. PO installed these but now wondering if I need 8. We cruise full time but are power frugal (ex sailors). I realize there are many variables but just would like to know what others Manatees carry. We have genset, high output alt.
Thanks
Bob
KASSIE 3693

It's not the boat, but the boaters that determines what power you need. Having a genset would reduce your need for battery capacity, I would think.

Kaylic said:

Well, it seems it's time to replace house bank. T105s (8) making 900ah. PO installed these but now wondering if I need 8. We cruise full time but are power frugal (ex sailors). I realize there are many variables but just would like to know what others Manatees carry. We have genset, high output alt.

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How long have you had the boat? How long have you been recovering from "power frugal"?

If not a long time, I'd suspect you might -- over time -- come to appreciate the extra power capability... and so I wouldn't suggest skimping now. Replace with 8, use them up over time, make a fresh decision after that, i.e., after you've had time to get over that "frugal" thing.

-Chris

We've been cruising for three years. We live happily with the mantra of less is more.
Bob

I carry two Interstate 1400 CCA 8D wet cells for the house, A 900 CCA for the main and a 450 CCA for the genset. I'm contemplating a remote 4D for the bow thruster, but so far the system seems OK. I'll likely add a small battery under the helm to support electronics before we go full time cruising. The 8D's are getting harder to change out solo.

The question of how much house battery capacity you need depends on how much DC you use, how long you sit at anchor, and what you have to recharge them.


I suspect that you can get by with four not eight GC batteries, but you need to tell us more to know for sure.


David

Kaylic said:

We've been cruising for three years. We live happily with the mantra of less is more.
Bob

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Fair enough. Sounds like you already know the answer to your question.

-Chris

Four T-105's and a group 27 no maintenance battery for starting the generator. I switched from the two 8D's because the weight. No maintenance battery because of the tight quarters made it difficult to check the water levels. With the increase cost of batteries when switching to T-105's, I put in a new Charles Marine charger to make the T-105 last, it worked 7 years and counting.

Kaylic, Hope this helps. This is what we inherited from the PO. Seems to work for us so far.

1 - Interstate 8D, 12 Volt deep cycle lead/acid (Engine starting)
6 - Interstate 6 volt deep cycle lead/acid configured in series parallel as one bank of twelve volts (House Bank)
1 - NAPA, group 24, 12 volt deep cycle lead/acid (Generator starting)
1 - Interstate 4D, 12 volt deep cycle lead/acid (Bow Thruster and Anchor Windlass)

Got a great price on t105s from my marina, so that made it easy. I'm not about to remove and install them, they gave me a good deal on that also . My banks are in 4 cases slid up to the hull side in engine room. Bolted down. There is a watering system attached so that makes it easy. New t105 are 220ah so 880ah total. Maybe we'll stop being so frugal and just go crazy and heat up the hot tub!
Bob

Kaylic said:

. My banks are in 4 cases slid up to the hull side in engine room. Bolted down.
Bob

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I've seen a photo I think of your engine compartment - sure gives you more room with them over to the side. Curious how they are bolted down? Next time mine get swapped out I may want to change the location. I'm not going to be changing them myself anymore so what the heck, if I have to pay for an install it might as well be worth more than just dropping them down into a box. I've got 2 8D's in that compartment that sit on platforms on either side of the engine.

I built that same battery bank (8 T105s) when I did the refit for my trawler. One of the things to consider would be how much you could use your inverter instead of the generator. My expresso machine and the microwave easily run off the bank through the inverter. Making the bank smaller tends to work the batteries harder for the heavy loads such as the microwave. There are no free lunches, so you have to put the amps back in the battery. But on days you will be cruising, you get to save the generator time. Really like the idea of not firing up the generator for a 10 minute job. If I were to do it again, I might have gone to 12 batteries to be able to go 2 days without charging. At $100 a piece in Delaware with no sales tax, they were certainly inexpensive enough.

Ted