Battery life expectancy questions

Most household electric kettles are in the 2kw range. Much more efficient energy wise to use the propane stove to heat water for coffee on a boat
 
Portland Tug25, we changed the batteries on our R31 (2014) a week ago. The original batteries were 5 ½ years old and losing their capacity. We selected Concorde Lifeline AGM 31XT batteries to replace the original batteries. These batteries have the same group 31 footprint of the original Universal batteries that came with the boat but have a 125 amp hour rating versus the 110 of the Universals. This increased our total battery bank to 500 amp hrs over the original 440 amp hrs. The Lifeline batteries do have the disadvantage of having posts instead of vertical tabs. That meant I had to reroute the cables to a horizontal arrangement instead of the vertical orientation of the OEM batteries. I wish Lifeline made the tab style on the group 31 like they do on their 4D and 8D batteries.
Here are some things I do to try and minimize the time and problems associated with changing the batteries on the R31.
Prep Work
Here is a photo of our original battery bank:

Note that the positive leads (red) are on the “outside” part of the batteries while the negatives are on the “inside” of the batteries (yellow). We set up the new batteries on the deck so that their orientation looks just like the original installation.


I also tape my wrenches since I don’t have insulated wrenches. I try to limit the possibility of touching a negative and positive post which can cause a fire or explosion. I also remove my ring as well. A LED headlight is useful so that you don't have to use a flashlight.

Removal
After turning off DC and AC circuits, turning off the inverter, and turning off the shore power at the power post, I start removing the positive leads first. On our boat, the Magnum inverter requires that if the positive lead is connected it must first have a negative lead attached.
As I remove the positive cables I take a cable tie and tie the cables together and label each set so I know which battery they came from. For example, we labeled right front, left front, left rear and right rear. We used red and yellow electrical tape (we bought these rolls at Home Depot), red for the positive and yellow for the negatives. We tape the end of the exposed cable so that other leads would not inadvertently touch other cables. See this photo of the taped cables.


After removing all of the positive leads we removed all of the negative leads. We then removed all of the batteries. The battery trays supplied by Ranger Tugs work well. I removed the hold down straps. I found through prior trial and error that the batteries don’t have to be lifted out of the tray, in fact doing so in this small space is a difficult task. There is enough play in the tray that the battery can be tilted and then you can slide the battery out of the tray and remove it from the lazarette. Here is a photo of the battery being tilted out of the tray.


Once all of the old batteries are out, I cleaned the trays and placed the new batteries in the trays. The straps are re-attached and the cables attached to the posts on the new batteries. Again, the negative cables are all attached first and then the positive cables. The positive terminals are then covered with the red insulators. The power is restored and the inverter restarted. Check your inverter manual as to how they stipulate you should shut down and restart your inverter after replacing the batteries. If you have any hesitancy about doing this yourself it may be worth it to have a professional shop do the installation for you. Hope this is helpful in your battery replacement task!
 
Excellent description and illustrations. Thanks for going to all this trouble to share with the rest of us. I have another year or two left on my AGMs and am already planning the dreaded exchange.

Jeff
 
Thanks for your comments, Jeff. I hope your eventual battery exchange will go smoothly. For me, the key is to label each set of cables coming off of a battery post and tie them together with the cable ties. The other critical element is to tape the terminals on each cable set. There is a lot of spaghetti down there and in the process of removing batteries I did not want any cable terminal to touch other terminals or battery posts.
 
BaylorU":5alovxoi said:
Following! My batteries are the originals (2012 C26, 4x 110ah AGM’s) and this past week they couldn’t run the microwave. Seems like they’re beginning to tire out.
Click to expand...

This weekend I removed the 4 batteries from my boat in preparation of installing new Northstar AGM's. The batteries were manufactured in 2015 installed by Fluid Motion and are sealed maintenance free.(Centennial Batteries) Last fall I noticed the voltage drop was quicker when using the Inverter without the engine running. No noticeable change with the engine running. I was still able to use the same devises but for less time. I use and abuse the house batteries. I don't have a generator and still want the comforts of home. Using 12.8 has 100% state of charge and 11.8 has 0% state of charge, my house batteries have seen 0% a few times and been at 50% (12.2V ) a number of times when at anchor. While cruising we use outlets, microwave, crock pot, coffee maker without issue. This winter I have noticed the house batteries after sitting for a week or two at below 11V and the thruster and Engine battery still sitting at just below 13V. I turn the charger on and with in a short time the house is showing full charge. I now have all four batteries on the bench marked engine ,thruster, house 1 and 2. I charged each one using a 10 amp portable charger for 2 hours. I waited about an hour after removing the charger to check voltage, each battery voltage reading ranged from 13.14V to 13.01V all excepted a charge. Today I again checked battery voltage 18 hours after charging, using a fluke 85 multimeter, Engine 12.98V, Thruster 13.01V, House (B1) 6.93V (B2) 12.93V. House battery (B1) did take a charge meaning it mostlikly doesn't have a dead cell just a great deal of Sulfation build up on the plates causing it to discharge quickly. I assume the battery sulfating is from discharging the battery to 50% a number of times and 0% a few times. I believe (B2) is not far from the same condition and has been supporting the circuit. Because I use the batteries for inverter use often I decided to go with a AGM that "advertises " more charging cycles 900 at 50% discharge, and ability to recharge quicker. I will monitor the battery voltages closer trying not to allow the them to go below 50% and may have to run the engine a few times while at anchor relying on the AGM's ability to recharge quicker.

Baylor you may have the same situation on your boat .You stated that the batteries were fully charged but not capable of running your microwave. (B1 or B2) could be providing very little and ( B1 or B2) could be marginal. The alternator is being required to carry the full load. The alternators capacity could be at maximum without back up from your batteries. Given the fact that your batteries are original 2012 batteries I would say they have had a good run. I will be happy with 5 full years of maintenance free service from the AGM's I'm installing.
 
One way to prolong the life of a Lead-Acid battery is to use a De-Sulfator. I used a pair of these on my previous boat which had 4 AGM batteries house batteries installed when I bought the boat. The De-sulfators kept the batteries going for the 13 rpt. 13 years before I sold the boat. I do not recall the brand, but they were made in Japan. I don’t know if there are any of these devices that are not made in China <sigh> but perhaps someone can shed some light on this.

Here is a description on how these small devices work:

A battery desulfator is also known as a battery regenerator. The second version of the name is a little misleading as it gives one the impression that a battery desulfator can regenerate just about any battery. That isn’t necessarily true. If your battery is not working as a result of internal damage or is shorted, no desulfator in the world can repair it. However, if the battery has lost a great deal of its capacity due to sulfation, then you’re in luck. Let’s not get too far ahead of ourselves, though, we were talking about battery desulfators.

A battery desulfator is a device that restores the capacity of a lead acid battery. That way, the lifespan of the battery is extended and so is its performance. These batteries are also known as pulse conditioning devices, battery reconditioners, and, of course, battery regenerators.

It all begins with the battery. If you store it in an uncharged state for too long, then lead sulfur will form little deposits on the lead plates and harden over time. How long to leave it uncharged pretty much depends on the battery, but generally involves leaving it only partially charged every time you charge it. When these lead sulfur deposits form on the lead plates, we say that the batter has been sulfated. That means it is now incapable of charging to its full capacity that you purchased it with. Keep leaving it uncharged for too long and the capacity grows smaller and smaller until it becomes practically impractical to use the battery any longer and you have to swap it out for a new one.

That is where battery desulfators come in. They send pulses of electricity throughout the batter. In some cases, those pulses of electricity will get the sulfate to come off the plates in flakes. The sulfate dissolves and your battery regains its capacity.

So you’re probably wondering why such a miracle of science and technology isn’t popular. Well, as it turns out, the battery industry, or at least the mainstream part of it, has an incentive to sell replacement batteries. In fact, most of the profit made by battery manufacturers comes from selling replacement batteries. They stand to benefit from the process of sulfation and so they don’t feel the urgent need to solve the issue in batteries. There has therefore been very little scientific research into the issue and understanding exactly what is happening under the hoods or any verification of the claims that are being made about sulfation. As a result, the market for desulfators is still very small and most battery owners don’t even know about it. That said, it is a growing market, no matter how small and we are hopeful that the setback to battery longevity caused by sulfation will soon be a matter of the past.
 
All the above is very informative, good read.
Question though......My 2017 CW AGM batteries are hooked up to shore power 24/7, even when the boat is stored in my boat garage at home . I was told by CW Rep ," just keep them on charger all the time"...not a problem.

Batteries ,after two seasons of use seem to be fine. Curious how other folks handle this issue??

Bill T.
 
Bill,

No issue with keeping the batteries connected to the Battery charger 24/7, in fact it is the best approach to keep your batteries healthy with modern battery chargers.

The only disadvantage I know of is if your boat is in the water at a Marina where other boats may not be properly protected from galvanic corrosion. A galvanic isolator should protect your boat from this issue though I have heard some have still had issues even with one. In that case, some advise to only connect to shore occasionally to keep the batteries topped off but minimize the depletion of the zincs. In any case this avoids consumption of the zincs and potential corrosion issues but could be harder on your batteries if they did not receive regular full charge.

In your garage there should be no issue with keeping them on the charger 24/7. It has enough smarts to keep them as healthy as possible.

The sulfation issue discussed above is caused by not fully charging the batteries. Keeping the batteries fully charged minimizes this.

Curt
 
Curious if anyone has looked into the Dragonfly Foam Core AGM batteries. Definitely a speedy AGM for sure although somewhat attractive given the number of cycles and depth of charge which seems like a way to effectively double your charging capacity without the added weight? Always looking at ways to increase charging capacity for lengthy times on the hook, cloudy days and not having to fire up the engine.
 
Do you mean the Firefly AGM battery? Dragonfly is a Lithium battery. Different animals!

Curt
 
Yes the Firefly AGM
 
Kaptajnen":aizv7svh said:
One way to prolong the life of a Lead-Acid battery is to use a De-Sulfator. I used a pair of these on my previous boat which had 4 AGM batteries house batteries installed when I bought the boat. The De-sulfators kept the batteries going for the 13 rpt. 13 years before I sold the boat. I do not recall the brand, but they were made in Japan. I don’t know if there are any of these devices that are not made in China <sigh> but perhaps someone can shed some light on this.

Here is a description on how these small devices work:

A battery desulfator is also known as a battery regenerator. The second version of the name is a little misleading as it gives one the impression that a battery desulfator can regenerate just about any battery. That isn’t necessarily true. If your battery is not working as a result of internal damage or is shorted, no desulfator in the world can repair it. However, if the battery has lost a great deal of its capacity due to sulfation, then you’re in luck. Let’s not get too far ahead of ourselves, though, we were talking about battery desulfators.

A battery desulfator is a device that restores the capacity of a lead acid battery. That way, the lifespan of the battery is extended and so is its performance. These batteries are also known as pulse conditioning devices, battery reconditioners, and, of course, battery regenerators.

It all begins with the battery. If you store it in an uncharged state for too long, then lead sulfur will form little deposits on the lead plates and harden over time. How long to leave it uncharged pretty much depends on the battery, but generally involves leaving it only partially charged every time you charge it. When these lead sulfur deposits form on the lead plates, we say that the batter has been sulfated. That means it is now incapable of charging to its full capacity that you purchased it with. Keep leaving it uncharged for too long and the capacity grows smaller and smaller until it becomes practically impractical to use the battery any longer and you have to swap it out for a new one.

That is where battery desulfators come in. They send pulses of electricity throughout the batter. In some cases, those pulses of electricity will get the sulfate to come off the plates in flakes. The sulfate dissolves and your battery regains its capacity.

So you’re probably wondering why such a miracle of science and technology isn’t popular. Well, as it turns out, the battery industry, or at least the mainstream part of it, has an incentive to sell replacement batteries. In fact, most of the profit made by battery manufacturers comes from selling replacement batteries. They stand to benefit from the process of sulfation and so they don’t feel the urgent need to solve the issue in batteries. There has therefore been very little scientific research into the issue and understanding exactly what is happening under the hoods or any verification of the claims that are being made about sulfation. As a result, the market for desulfators is still very small and most battery owners don’t even know about it. That said, it is a growing market, no matter how small and we are hopeful that the setback to battery longevity caused by sulfation will soon be a matter of the past.
Click to expand...

As a footnote, I found a small desulfator manufactured in the U.S. (Jamestown, N.C.).
Google “MAX DESULFATOR MD-12”.
Listed for less than $20 incl. shipping, I might give it a try.
 
S@LTD":3u6b8kwn said:
Curious if anyone has looked into the Dragonfly Foam Core AGM batteries. Definitely a speedy AGM for sure although somewhat attractive given the number of cycles and depth of charge which seems like a way to effectively double your charging capacity without the added weight? Always looking at ways to increase charging capacity for lengthy times on the hook, cloudy days and not having to fire up the engine.
Click to expand...

Alternatively you could buy a second solar panel for the difference in cost of the batteries. The solar panel has a even better life and could allow indefinite time on the hook in all but the worst weather. Of course if you have the $$$ you could do both or even go to Lithium.

Curt
 
Yeah been thinking about the second panel as it is a reasonably priced upgrade. Also, Trying to look for something for those longer periods of rainy/cloudy days. We use the roof rack real estate for other things as well so was trying to strike a balance with increasing capacity without taking up added space. Not interested in Lithium for our needs or for the $$. Was just curious as to anyone’s experience with these Firefly batteries.
 
The information stated that 80% discharge is acceptable with theses batteries. (Firefly) 80%= approx. 12V. The inverter installed in my C26 shuts down at 11.6 with load so right around 12V. I have done this a number of times causing sulfation do to low percent discharge and never fully charging while traveling and anchoring. Unfortunately relying on solar and the engine doesn't always fully charge the batteries. Especially when using power while trying to replenish the batteries. If the firefly technology works as advertised a two battery bank is equivalent to a 4 battery bank. 50% or less discharge is hard on lead batteries. The ability to go to 80% without damaging increases usable capacity. That comes with a cost slightly higher then a good AGM battery. $550.00 Firefly , 300.00 Northstar. Seems like good alternative. Something to research more!
 
Cutwater28GG":for284rn said:
here's my math on this.
Click to expand...
Interesting take on this, thanks. Might be interesting to plug in Lithium battery numbers.
 
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