Battery Question

Brian D · Jan 11, 2012

Check out Wal*Mart for Marine Deep Cycle batteries. I have used them (Gp 27) for several years. Currently have a Wal*Mart battery in my boat. I have had no problems with them. They are wet cells, so if you are using Gel or AGM, then you might have to look elsewhere.

Jackdaw · Jan 11, 2012

Duc,

+1 on the walmart batteries. We have 3 of the G27's on kestrel, one for start and two tied together for the house. We use a Blue Sea Systems ACR to charge them smartly when underway. Also re-wired the crazy Beneteau handles so one is a combine. PM me if you want to see pictures or have more questions.

EDIT - If you go the Walmart route, make sure your house batteries are the marine ones and marked DS, for deep cycle.

ramblinrod · Jan 11, 2012

If you purchased good batteries a few years ago, and have charged maintained them well, this should not be a pressing issue.

Good marine batteries, maintained and treated well, should last about 10 years.

Unfortunately, many cheaper batteries, are really automotive batteries with marine labelling, and don't last as long.

Look for a quality marine brand name like Trojan or Royce.

Do not use a starting battery for a house battery; they do not like long discharge cycles. Do not use a deep cycle battery for a starting battery, they do not provide the required cranking amps, causing the voltage to dip.

Do not allow any battery to sustain a prolonged period at any state of discharge before recahrging, and do not allow any battery to discharge more than 50% of capacity ever.

Tom · Jan 11, 2012

Happy New Year everyone!

I don't know what I'm doing wrong, but I have always used auto batteries and have never had a problem. Granted, my needs are low, radio, sounder, gps, running lights and house lights. I recharge with solar. I'm not saying it's right or wrong, just saying it works well for us.

Tom
s/v GAIA

Maine Sail · Jan 11, 2012

Ducati said:
I must admit, I know very little about marine electronics.

A few years ago we paid mucho-dollars for two new batteries for our boat.
We have one assigned to start the engine and the other as the house.

Question? Would a couple standard 12v automotive batteries which cost substantially less do the same job? We paid almost $250 each for our present batteries and when I look at the cost of an auto battery $90, I have to think that it might be better buying one of those next time.

Thanks

Some thoughts..

1- One battery as a house battery on a 36 footer is quite possibly on the small side. This could be why you need replacement so soon as it may cause your discharges to be excessively deep..

2- Automotive batteries will not withstand deep cycles for very long. They can provide for house loads but would have a shorter life doing so compared to a thicker plate battery. It would be fine in a dedicated starting only situation but not for running house loads consistently.. You'll want a "deep cycle" battery for the house loads. These batteries will have thicker plates and are designed for deeper discharges.

Normally cycling the bank between 50% SOC and 80-85% state of charge, when away from the dock,is what you'll be doing so you really only have about 30-35% usable capacity of your house bank. So, if you use 60Ah per day and you want to be able to go for 2 days before recharging, you'll want a house bank in the 400 Ah range due to the 30% usable capacity "gotcha". Good quality deep cycle batteries can be purchased as inexpensively as Sam's Club under the Duracell label. These are really Deka / East Penn deep cycle batteries and are the SAME EXACT battery West Marine puts their label on. The only difference is the price at Sam's is about half of West Marine..

3- I can't say much as to what you paid without knowing what they are. Group 24, 27, 31, or 4D or 8D. Also what type of battery are they wet cell, AGM, GEL..? 12V bank or 6V in series / parallel..?

4- How old are these batteries you have now and how have you charged and cared for them? There may be an issue that should be resolved before spending more money on new batts, only to do it again in another 2 years. Depending upon where you are, and how you use your batteries, I see an average life of wet cell deep cycle batteries ranging from 4 - 7 years, GEL batteries 5-9 years and AGM batteries 2 - 5 years.. A "couple of years" is quite short.. These averages are in Maine where are temps are cooler and this can lead to longer life. In warmer climates batteries generally last less long on average.

5- Do you have a battery monitor or any way to know how deeply you are discharging your bank?

navigator97 · Jan 11, 2012

For what it's worth, I have two Die Hard Marine Deep Cycle Group 27 batteries on our H-33.5. I use both of them for both starting and for house. I have talked to battery manufacturers and they have said that for the size of my engine, that the Deep Cycle Marine battery would be fine. My engine is rather small. It's a Yanmar 2GM20F 18Hp Diesel and doesn't draw a very large starting current. I alternate which battery I use for each use of the boat. Since one of the items I put into the logbook each time is which Batt. No. I use that day, it is easy to know to use the other the next time. These batteries are coming up on 6 years of use this coming spring. At least twice a year I check water/electrolyte level and top off with distilled water. For winter storage, after topping off with distilled water, I put on the 3 stage charger long enough to give them a good trickle charge top off. I only loose about 0.1 Volt after the winter on the hard. The batteries stay on the boat with all cable disconnected from them. No problems. I will probably get another year use out of them this coming season. Works for me.

Maine Sail · Jan 11, 2012

navigator97 said:
For what it's worth, I have two Die Hard Marine Deep Cycle Group 27 batteries on our H-33.5. I use both of them for both starting and for house. I have talked to battery manufacturers and they have said that for the size of my engine, that the Deep Cycle Marine battery would be fine. My engine is rather small. It's a Yanmar 2GM20F 18Hp Diesel and doesn't draw a very large starting current.

Most deep cycle house banks have little issue starting a small aux diesel engine. Also when you put batteries in parallel, what many sailboats over 30 feet have for house banks, you add the amps, and this includes cranking amps. Our bank of group 31 deep cycles supplies over 3000 cranking amps at 70F.

I used to start my massive Cummins turbo diesel on Trojan T105 golf cart batteries, even in the dead of winter... Personally, I much prefer two banks of deep cycles because if one bank gives up the ghost your reserve/starting battery can handle the use as a house bank just fine until you address the issue. Starting our 44HP 4 cylinder Westerbeke uses less than half an Ah....

Benny17441 · Jan 11, 2012

It might help if you tell us what you purchased at $250 a piece. I don't know what kind of electronics you support and what kind of sailing you do but for most us a couple of deep discharge wet cells from Walmarts do the job at about $150 a pair. Oh, and if one fails on the road just pull over in the next inlet or pass and find a quick replacement.

Stu Jackson · Jan 11, 2012

Ducati, you're a nice to see regular here. Perhaps you could pick up a lot of answers to your questions by reading some of Maine Sails's Musing with Maine Sail articles about electrical systems and components, in the Featured Contributors section of Forums.

Batteries are well presented in both the West Marine Advisors, Electrical (http://www.westmarine.com/webapp/wc...51&catalogId=10001&page=West-Advisor-Articles) and www.amplepower.com, tech tab, download the Primer. Great reading about battery types and charging.

Bill Roosa · Jan 12, 2012

Just read the ample power.com technical documents. WoW, what a sales pitch. You might want to break out the salt when reading this stuff. I'm certain that some of the things in there are misleading and suspect they are wrong. ie 3-way switches go bad a lot, "all the boats we know of that have electrical problems either had a lightning strike or had 3-way switch installed" REALLY?? Given the number of 3-way switches out there I would not say that is much of a statement about the failure of 3-way switches. More just a statement of fact that incorrectly suggests the 3-ways are causing the problem.
There are better sources. Remember they sell stuff so "buyer beware"

Bill Roosa · Jan 12, 2012

To answer your question Ducati
Auto start batteries could be a solution IF (and only if) you have some pretty hefty solar-wind generation and your electrical loads are very light. I think I'd still go with a deep cycle just to give more AH and flexability in charging schedules.

Maine Sail · Jan 12, 2012

Bill Roosa said:
Just read the ample power.com technical documents. WoW, what a sales pitch. You might want to break out the salt when reading this stuff. I'm certain that some of the things in there are misleading and suspect they are wrong. ie 3-way switches go bad a lot, "all the boats we know of that have electrical problems either had a lightning strike or had 3-way switch installed" REALLY?? Given the number of 3-way switches out there I would not say that is much of a statement about the failure of 3-way switches. More just a statement of fact that incorrectly suggests the 3-ways are causing the problem.
There are better sources. Remember they sell stuff so "buyer beware"

You are spot on in your assessment! I am shocked that Stu still points to it. While lots of it is correct much of it is nothing more than marketing gibberish.

I have yet to have or see a 3 way fail in the manner they describe and see them starting HUGE engines on power boats. This is the most popular switch ever sold and there are MILLIONS of them out there.

Occasionally I get one where the contacts have worn or the contact is no longer as good as it was due to corrosion but what they claim as a "regular occurrence". Not yet seen it... Their points on fusing the negative lead can certainly work, it's a circuit, but are against ALL current safety standards and do not meet ABYC, USCG or CFR (Code of Federal Regulations) safety standards.

Bill Roosa · Jan 12, 2012

Yea, I would like a quick way to disconnect everything in an emergency. aAmost sounds prudent. Diodes and solenoids have left plenty of folks staring at the ignition switch though and amplepower seems to think they are the cat's meow. Course their system needs automatic controls to work.......... things that make you go hummm.

BarryL · Jan 12, 2012

lots more info needed.

Ducati said:
Question? Would a couple standard 12v automotive batteries which cost substantially less do the same job? We paid almost $250 each for our present batteries and when I look at the cost of an auto battery $90, I have to think that it might be better buying one of those next time.

Hey,

What is 'the same job'? How do you use your boat? What are you looking for the battery to do?

If you just race your boat, and you really, REALLY care about sailing performance, you want batteries that are very light, and don't need to provide a lot of power for a long period of time.

If you cruise your boat, and spend a substantial amount of time at anchor, and run heavy electrical loads like refrigeration, computers, TV, lights, water pumps, etc. You want batteries that are durable, can be deeply discharged, can accept a high charge rate, etc.

Think about how you use the boat, how you want to use the boat, and then you can decide what kind of batteries are right for you.

Barry