Intelligent lead-acid battery choice

[Suliwar]

As far as I understand You have 6 batteries connected in parallel. This is not a problem when You are living on board since, in case of a battery failure, You will notice the malfunctioning of Your electrical system and take action.
Instead when You are NOT on board for a week or more, leaving 6 batteries permanently connected in parallel increases by 6 times the probability of a total battery failure. In case of a failure in one of the batteries, since connected in parallel, the other batteries will tend to support the system voltage by discharging all their current into the failing battery and, once completely discharged for some day, all the other otherwise healthy batteries will be ruined as well.
For this reason, each time we leave our boat unattended for some day, we always open the parallel connections between all our batteries (a switch on one pole of each battery is sufficient).This way, any failing battery cannot damage the others.

[roland stockham]

My main bank is 2 6v 400ah Trojans bought in 2006. They have been boiled dry once and lest flat a few time when the boat was stored (worried about leaving them on charge unattended) Still working but possible about due for replacement as I think they are down to about 300a/h. Before I bought them I was getting about the same battery life as you...

[Maine Sail]

Originally Posted by snotter

John, are the Trojan SCS200's a true deep cycle? If they are what Maine Sail calls a true deep cycle I think that is the way I should go. Also, if the SCS200's have more room above the plates, they would be better at surviving healing when sailing on the wind since there would be more water to keep the plates submerged.

The SCS series are Group 24, 27 & 31 batteries. The SCS200 is a G-27. Trojan rates the SCS batteries at 600 lab cycles. The T1275 (Golf Car 12V) & Trojans GC2 batteries, T105 etc. are rated at 1200 lab cycles. The stickers on all of them say "deep cycle"...

[smac999]

Originally Posted by ranger42c

Or if that doesn't work... you can install AGMs on their side... so AGM GC2s could maybe work that way?

-Chris

I have put AGM batteries on their side twice on clients boats and both catastrophically failed within 6 months (lost house bank while out on water)

I will never mount them sideways again. these were US battery. maybe better luck with better ones.

[CapnBazza]

The question is a bit like asking which blanket do I need to send my smoke signals efficiently. My advice would be to buy a cell phone or a decent radio if you're going far offshore. Have you looked at LiFePO4 options?

[ranger58sb]

Originally Posted by smac999

I have put AGM batteries on their side twice on clients boats and both catastrophically failed within 6 months (lost house bank while out on water)

I will never mount them sideways again. these were US battery. maybe better luck with better ones.

Sorry to hear. Given all the military mounting systems Odyssey and Lifeline advertise, maybe they have a better track record. Maybe Maine Sail will comment...

-Chris

[a64pilot]

I don't understand Skip.
We sit on our box, its under the Settee. Best answer I think is to cut out the box and lower it.
Literally cut it, lower it and re-glass in the gap.
The covers are 3/4 and sit into recesses in the top of the settee base and are flat when sitting in their recess.

[skipgundlach]

Originally Posted by a64pilot

I don't understand Skip.
We sit on our box, its under the Settee. Best answer I think is to cut out the box and lower it.
Literally cut it, lower it and re-glass in the gap.
The covers are 3/4 and sit into recesses in the top of the settee base and are flat when sitting in their recess.

Ah. I didn't realize the location.

Mine's in the engine room, and while I sit on it for convenience, there's room at the top.

What's under that which prevented it from being further down to begin with?

L8R

Skip

[john61ct]

Originally Posted by smac999

I have put AGM batteries on their side twice on clients boats and both catastrophically failed within 6 months (lost house bank while out on water)

I will never mount them sideways again. these were US battery. maybe better luck with better ones.

Do you know (saw evidence for the idea?) that it was the mounting orientation that killed them? Does U.S. say that should be OK?

​Northstar, Odyssey and Firefly is the list I've culled from thousands of threads for good deep-cycle AGM brands. And Lifeline.

Firefly explicitly states sideways is OK, but "not upside down" 8-)

[a64pilot]

Originally Posted by skipgundlach

What's under that which prevented it from being further down to begin with?

L8R

Skip

I hope not the hull, I hope they built it as deep as they needed, not as deep as they could. An exploratory hole will tell, a bulkhead is in the way of just looking
I think the boat came with two large Gel batteries. I know it had a dumb 30 amp Raritan charger that was connected with 20+ feet of 10 GA wire to the bank.
I contemplate going back to Gel, its my understanding that if treated right, they can last a long time.

However I believe that there is a lot of Logic in Sailorboy's idea of using inexpensive GC batteries, not obsessing over them and just replacing them as needed as opposed to buying real expensive batteries, obsessing over them cause they cost so much, and in the end you save no money, just obsessed for years.


My local Sams club price for a GC2 is $84.52 today, average price for a Lifeline GPL-4CT is close to $300

Will the Lifelines last more than three times as long as a GC2?

Umm maybe, if I baby them and put them to bed correctly every night etc.

[GrowleyMonster]

A pair of L-16's in series gives you a respectable 380ah at 12v. Tall, yeah, but with only two batteries to tuck away somewhere, it could be a solution.

My propulsion bank is 8 Eveready GC-2 6v batts from Sams Club. 3 years in and they show no signs of age yet. The price was right. Trojans better? Sure. But better enough to justify the price break? I am guessing no. Meanwhile my old house bank is getting pretty weak and I am probably not going to buy new ones. A couple of DC/DC converters running off the prop bank, and a small inverter, and I think I can dispense with the house batts and charger.

Then, there are LiFeP04s. But not for me. I can't justify the price, even at double the lifespan.

[snotter]

Originally Posted by Maine Sail

The SCS series are Group 24, 27 & 31 batteries. The SCS200 is a G-27. Trojan rates the SCS batteries at 600 lab cycles. The T1275 (Golf Car 12V) & Trojans GC2 batteries, T105 etc. are rated at 1200 lab cycles. The stickers on all of them say "deep cycle"...

Maine Sail, Thanks for the information. Will the Trojan SCS200 in your opinion likely provide more cycles than Walmart/costco type of deep cycle batteries?

[snotter]

All, thanks for your replies.

I too, like many of you feel that GC-2s provide the most bang for your buck; however, I have just too many irons in the fire to tackle moving the bank to the main saloon. The boat was relaunched last July after an extensive refurb--new engine, xmision, shaft, mid bearing, stern bearing, stuffing box, new exhaust system (both for the new engine and for the old genset), much new plumbing, wires, lighting, etc., etc. I did all that work myself. To get the yard off my back, I threw money at them to paint the boat stem to stern and top to keel. In addition to my work below, I had a hand in much of fiberglass work (fabricating a new helm station and installing much new navionics).

I took the boat down the ten-tom last fall. Since I arrived on the gulf coast work has proceeded non stop--new rudder post bearing, complete survey, and taking care of all items on that the surveyor pinged me on. All this work was done by me. Lee Creekmore, the surveyor, has rated the boat above average condition. I say these things because I have been very very busy spending money on the boat and working on the boat. I would very much like to have more modern battery technology than lead-acid installed, and have the batteries placed outside of the engine room; however, I do not have the time right now--there is more pressing work I want to get done before my wife and I head to the carribean hopefully this year. Work that I would like to get done is to get my genset back together and operational again, get an arch installed, move the radar, and solar panels and davits to the arch, etc, etc, etc. I have to work by priorities. If I were to move batteries to under the settee at this time, I have to move the fish-finder transducer and the flux compass. I have no idea where to locate those things. For this go around, I have made the decision to stay with group 27, 12V batteries which will be plug and play for me.

[ranger58sb]

Those pesky priorities again.



Yep, sounds like you've had/got your work cut out for you, and some things can be solved relatively easily just by replacing what you've already got and that you already know will work.

FWIW, I haven't understood the difference between G27s and G31s. Just haven't looked closely enough, I guess. Seems footprint is similar, dunno if capacity over various brands changes...

-Chris

[john61ct]

Originally Posted by snotter

Maine Sail, Thanks for the information. Will the Trojan SCS200 in your opinion likely provide more cycles than Walmart/costco type of deep cycle batteries?

It is helpful to use precise terminology.

The only deep cycle batteries sold at Costco are the GC type you don't have room for. Walmart far as I know sells none at all.

If you are talking about the dual-purpose starter batteries that big-box marketing liars slap "deep cycle" stickers on, then best you use "pseudo deep cycle" or if you don't want to be so disparaging "dual-purpose starter" batteries.

And the answer is yes for sure, at least 2-3 x the cycles.

And as MS pointed out the SCS series is still not so great. Sorry if already covered above, but are you sure the GC-12 form factor doesn't fit?

Trojan J150 or T-1275 would be **much** better.