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Discussion Starter · #1 ·
Okay, totally noob question, but it seems crazy to me that all three batteries would be dead. I have 1 starter battery and two (large) house batteries. I'm still learning how to monitor/maintain all the systems on this still (fairly) new boat to me. Last year I never had a problem with the batteries and kept the boat plugged in while at the dock.

I've never used a digital multimeter before, but bought one for the boat that I could use while learning how to trouble-shoot/maintain the various systems on the boat.

So I drive up to the boat today to do some things prior to launch and one of the first things I want to do is test the batteries with the new multi-meter. I didn't have the boat plugged in, and nothing was on in the boat. The starter battery read 1.357 volts, house battery 1 read 1.632 volts, and house battery 2 read 1.357 volts. The previous owner installed a fourth battery (small like the starter battery), and it actually read 12.99 volts. So what the heck? Are the batteries toast and why would they have crashed over winter? The boat's been in indoor heated storage so it's never gotten below 40 degrees. I go up to the boat about once a month in the off-season and plug in the battery charger for at least 2 hours.

So after I took these readings I plugged the boat in. I have a Link 2000 Xantrex battery monitor, and it went throughthe AC In, Charge, Accept, and Float cycle until it stayed green in the Float cycle. Both house batteries read on the Xantrex around 13.35 to 13.45 volts.

Any advise or insight is appreciated. I've seen what house batteries can cost and I'm not eager to shell out $400+ for each battery. :(
 

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Possible that you got a bad reading of the voltages. One has to ensure that real contact is established. Propose you re-do the measurements, all three to have such low readings?

If the voltages really are around 1-2 V. then your batteries are toast, as you suspect. It is possible to re-charge a battery that has been dead, but it will not have any capacity. There are many stories on how to do this, but in reality, a 12 V battery that has had 2V readings for some time is dead, more dead than Polly the parrot.


If you have to buy new batteries, shop around. Generally, there are huge price differences in batteries - differences that are not refelcted in quality.

/J
 

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Dirt Free
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Next year for winter storage, charge the batteries then disconnect the negative conductors. If the batteries are in halfway decent shape they won't lose much.
 

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Discussion Starter · #7 ·
Thanks all. I took a reading on each battery three different times, and I tried to make sure I had really good contact; so yes, I think those readings are correct. I did not know I was supposed to take the negative cable off each battery. Could that have ruined them?

Also, I've never had to purchase big batteries before. On my small boat a walmart battery worked fine for a starting/house battery. The two house batteries on the Beneteau 361 are pretty large, like two feet across, or there abouts.
 

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2' long batteries ,,, sounds like 8D's. Cheap ones are about $400 ea.

You may be able to make do with much smaller, less expensive batteries depending on how you use the boat. I'd suggest you get an experienced buddy to take a look at what you have and assess what you need before your dent that credit card.
 

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If all these options fail.....

Pull them out and take them to a "Battery Center", A store that specilizes in batteries and have them "load tested". It's a special tester that stresses the batteries. It only takes a minute for each battery. They will be able to tell you a lot once the test is conducted. Normally this is a free service. I would not recommend a car care store.
 

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Oh, i forgot. The big commercial battery centers ussually buy used batteries from warehouse fleets. You can HUGE deals on 8D's and other large batteries. Ussually you can get them used for $100-200 bucks depending on useable life left.
 

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Thanks all. I took a reading on each battery three different times, and I tried to make sure I had really good contact; so yes, I think those readings are correct. I did not know I was supposed to take the negative cable off each battery. Could that have ruined them?

Also, I've never had to purchase big batteries before. On my small boat a walmart battery worked fine for a starting/house battery. The two house batteries on the Beneteau 361 are pretty large, like two feet across, or there abouts.
If I were me, I'd charge them individually then have each one tested to check the condition before buying new ones.
-CH
 

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Your voltage readings indicate the what you assume is start is actually house and what you assume is house is start. The two batts at 1.357V are in parallel. That is why the have identical voltages.

Leaving the batts on the boat is fine, if fully charged, like your 12.99V batt was. Your fatal flaw was in not 100% disconnecting them from the boat. If they sat at anywhere below 10.5 V for even a few days you have lost a LOT of your cycle life. The cold weather may have helped but the batts have been water-boarded/tortured and may never recover from it....
 

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Discussion Starter · #13 ·
Thanks All. I appreciate all the insight and advice. Would a place like Interstate Batteries have marine type batteries? That's the only Battery Center type store that I know of around me (Central Ohio).
 

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If you do replace the 8D conside 6 volts. They are much easier to handle

Do you ever equalize the batteries? If not you may be slowly suffacating them if they are wet cells.

Batteries and your electrical system/ charging etc is one of the most expensive and least understood systems on your boat for most sailors I have found. I would suggest boning up on that by reading the myriad of posts MaineSail has written or getting a basic 12 book to read, It can save you thousands of mispent dollars on misssmatched systems as well as maintainence which is quite simple

Dave
 

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If you do replace the 8D conside 6 volts. They are much easier to handle
1. Many cruisers replace their 4D and 8D batteries with 6 volt golf cart batteries. In general you get more usable amp hours for less cost. Frequently two 6 volt batteries will fit in the space previously occupied by one 4D. Also they are physically easier to handle.

2. Make sure that you replace all the batteries that are connected together (including when you have your off-1-2-all switch set to "all." A charged battery will charge a discharged battery. Ultimately all of the batteries will end up at the voltage of the worst battery in the group. It is a lot of money for most of us but any alternative will end up costing you more.

3. All batteries lose voltage over time. The purpose of disconnecting the leads during winter storage is to make sure you don't have some unknown load drawing the batteries down. It is not necessary, it is just an additional safety check. If the boat is stored inside (or if you get permission outside) put a trickle charger on the batteries over the winter or bring them home and put them in your basement with a small charger attached.

Fair winds and following seas. :)
 

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i have 4- 6V golf cart batteries. 2 each connected for 2 - 12V banks. they stay in the boat over winter & get charged once a month. i don't need a starter battery to start my yanmar 2GM20F. the batteries were installed in 2002, & still are ok
 

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Are the golf cart batteries the inexpensive acid flooded type, the much more expensive AGM, or some other type (SLA)?
 

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Sailboat Reboot
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Are the golf cart batteries the inexpensive acid flooded type, the much more expensive AGM, or some other type (SLA)?
Flooded
 

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I have a single group 24 that may need replacing in the coming year. I don't need more capacity for my uses. With an outboard, if the battery ever goes dead I just pull the cord on the motor to start it.

Are there golf cart batteries that are small enough that two would fit into the footprint of a group 24 battery? I like the idea of having two smaller ones for ease of removal/transport, but don't really have room for much more than I have now.
 
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