Did we trash our batteries?

[jen1722terry]

Hello again, friends,

As some of you know, we live half the year in New Hampshire and the other half in Nova Scotia. Nova Scotia had a brutal (for them) winter with several cold nights (just below zero).

Our CD 31 was shrink-wrapped in Nova Scotia last winter, including our 160-watt solar panel on the stern davits. We had also shrink-wrapped the boat and solar panel in the winter of 13/14 and the panel still kept all three batteries topped up in a very cold and snowy winter in Portsmouth, NH.

When we arrived at the boat today in Nova Scotia we noticed three things:

1. All 3 batteries were stone dead (2 Grp 31 Deka AGMs for the house and one Grp 24 Deka AGM for starting). All the batteries were new in 2010.

2. The contractor had install two layers of shrink wrap over the solar panel.

3. The controller for the solar panel controller seemed to be functioning, with a green light glowing.

We did a visual and checked grounds and cables and all seemed normal. We uncovered the solar panel and worked on the boat for two hours in bright sunshine, but no charge registered on the battery meter for the house and the starter batteries. None of the boat electrics worked.

Tomorrow, we plan to return to the boat and see if the panel made any progress in recharging. If it did, can we then trust the batteries? Do AGMs freeze and become useless when the charge runs down in very cold weather?

If the batteries are toast, at least we're hopeful to find a tractor supply house with AGMs at decent price up here near Halifax.

Thanks in advance to you all,

Jenn and Terry

[Astronomertoo]

Jenn and Terry,
Wow. I am sorry to hear how they wrapped your solar panel system. It sounds like you had a good system. With your batteries disconnedted (OFF) with no loads all winter I would expect them to survive, even if under 12V. But with your normal charging they would have maintained topped off unless they were pumping a lot of water. If the batts were standard lead acid cells I would say yes, they would likely have discharged and not only frozen internally if there were serious freezes, but would then have likely split the boxes. That is because the electrolyte in the cells would have become more water (lower specific gravity) and less acidic with discharge. BUT for your batteries I would personally contact the manufacturer, and ask for an engineer to talk to which can tell you if you can put a charger on them and try to save them. Regardless if they froze or not HE will want to know the resting voltage of each battery, like 6 or 10V. But first, you wrote your electrical system is dead. I assume with the fuses and breakers ok and ON?
If you can measure with a volt meter directly at the batteries and they are 12V batteries, and read very low voltage, like less than 7 V, they are dead, and would likely never take a full charge, and surely not store anywhere near full ampere/hour RATED capacity. If you see good local voltage, over 10 V, and it does not show on your electical panel meter, you may have a cable connection or protective fuse problem. Or someone disconnected them (or a jumper) for you? Before connecting or disconnecting primary DC fuses make sure you turn OFF the manual battery switch to prevent a flash if there is something shorted. Then make sure the primary battery fuse(s) is good, and the voltage is correct to the fuse. Even if your battery is very low voltage, your power panel meter should still read the same thing you read with a portable meter at the batt cells. If the batteries are all dead, or nearly so, and been sitting dead or shorted with a load all winter, then I would never trust them out on the water.
Let us know what you learn.
BobC
(I&C/E design engineer, retired)
Moon Shine

[Maine Sail]

Jenn & Terry,


Sadly yours is not the first nor the last of this sort of story we will come across. This does not have to happen but sadly it does.

Best Practices:

#1 Batteries should be 100% disconnected from the vessels DC system for long term winter storage.

BATTERIES SHOULD BE CHARGED TO 100% SOC RIGHT BEFORE DECOMMISSIONING (EQ IF SUITABLE)
BATTERIES PHYSICALLY DISCONNECTED FROM THE BOAT
BATTERIES SHOULD BE PHYSICALLY DISCONNECTED FROM ONE ANOTHER
BATTERIES SHOULD BE PHYSICALLY DISCONNECTED FROM CHARGE SOURCES

Most all boats have some sort of parasitic loads that will eat your unattended batteries. As temps drop so does the "useable Ah capacity" so even a small parasitic load at 80F becomes a much larger parasitic load at 0F because you have less usable capacity. The only sure fire way to stop this is to fully disconnect the batteries from the vessel.

In this image you can see all the negatives have been removed from the battery terminals and zip tied so that they can't fall back in touch with them over the winter.


BTW when I reconnected this bank of Lifeline batteries three weeks ago the battery voltages were above 12.96 volts after sitting since October 18th 2014....! There is no need to charger batteries all winter in cold climates as self discharge slows to a dead-crawl due to the temps.

#2 Long term stored & unattended batteries do not need to be left charging, especially AGM or GEL.. This practice is only asking for trouble. Chargers fail, solar panels become occluded with snow or ice and batteries fail internally. Charge the batteries to CHOCK FULL in the fall then 100% disconnect them from the boat. You now risk no chance of a short, battery fire, charger failure, a solar panel becoming occluded or chronic over charging a battery with limited electrolyte.

CHOCK FULL for Deka AGM batteries is when they are accepting 0.3A of charge current at 14.6V for every 100Ah's of capacity. At this point they are ready for winter storage.

#3 Disconnect the PV array from the solar controller on the panel side.


So why did the solar controller not re-charge the batteries? It was doing exactly what it is programmed to do and that is to prevent a battery explosion or potential fire by not charging into a potentially failed battery that may have lost a cell or internally shorted. Most every reputable smart charger and smart solar controller will not charge a battery with very low voltage as it treats this as a bad cell or unsafe to charge battery. So when the panel becomes occluded and the parasitic loads go to work on the bank, because they were left connected, and drop batt voltage to the 10V range, it's bye-bye solar.......

As for the batteries your Deka's AGM's were likely already on their last legs at 4 years so you probably did not lose much. Based on many, many, many capacity tests on AGM's your batts were probably at 45-65% of as new capacity. Unless you are really taking advantage of the benefits of AGM's flooded batteries will cost you a lot less.

If you stick with AGM I would urge you to buy a premium AGM battery such as Nortstar, Lifeline, Odyssey or Firefly. The Deka battery is not a true deep-cycle AGM and the recent Practical Sailor "Partial State of Charge" (PSOC) testing they showed this to be the case.

Practical Sailor May 2015 - Fighting Sulfation In AGM's

P.S. In well over 25 years of charging to 100% full and disconnecting batteries from the vessel I have never once had a failed battery come spring, not once. Contrast that to 4-5 customers every winter who do what you guys tried and then destroy their batteries. Last week it was ruined house bank of $$$$$$ 8D Lifeline batteries on a power boat where they left the "trickle charger" charger connected to the start bank and the battery switch set on ALL to charge everything. Problem is someone turned the switch from ALL to OFF and the batteries were still connected to the vessel.... Cha-ching $$$$$$...

[jen1722terry]

Thanks so very much to Bob C and Mainsail. This has been an education in marine battery systems.

Tomorrow, we'll put the volt meter on a three AGMs and see if there is decent voltage - unlikely based on the charge indicators. If all is as suspected, we'll order new batteries

If it were possible, we would have a marine electrician check the entire systems, but such skills are rare here in rural Nova Scotia. And this time we'll try to order the best batteries locally available.

But what kind? We're not crazy about lead-acid. Are gels better than AGMs or vice-versa? We'll search the Prac. Sailor archives before we spend the money.

Again, sincere thanks to two gentleman who spent a good deal of time sharing very thoughtful answers to a vexing problem. With luck, we'll be in the water and sailing by July 1.

Jenn and Terry

[Maine Sail]

Thanks so very much to Bob C and Mainsail. This has been an education in marine battery systems.

Tomorrow, we'll put the volt meter on a three AGMs and see if there is decent voltage - unlikely based on the charge indicators. If all is as suspected, we'll order new batteries

If it were possible, we would have a marine electrician check the entire systems, but such skills are rare here in rural Nova Scotia. And this time we'll try to order the best batteries locally available.

But what kind? We're not crazy about lead-acid. Are gels better than AGMs or vice-versa? We'll search the Prac. Sailor archives before we spend the money.

Again, sincere thanks to two gentleman who spent a good deal of time sharing very thoughtful answers to a vexing problem. With luck, we'll be in the water and sailing by July 1.

Jenn and Terry

GEL, Flooded and AGM are all still "lead acid" batteries. The differences are in the electrolyte.

GEL's can be some of the longest lasting however they really do need to be installed as a system as they don't do will with over charging and should be temp compensated for charging. To give you an idea, based on lab data comparing Deka GEL to Deka AGM, they rate their GEL batteries at 1000 cycles and their AGM batteries at just 300 cycles. In the real world you are usually lucky to see half of that due to the PSOC environment, but I regularly see GEL's exceed 10 years when properly charged.
I can't say anywhere near the same for AGM's. The Firefly AGM looks like it will change that but the technology is new.

AGM's should also be installed as a system though they rarely are and this often results than less than stellar cycle life. AGM's vary widely in how they deal with PSOC use on boats. The "premium" AGM's generally doing better than bargain AGM's..

Good deep cycle flooded batteries such as golf cart batteries are by far and away the best value in terms of cycle life to $$ to Ah's per sq inch of floor space.

Be aware that many batteries that are labeled as "deep cycle" are not really a deep cycle battery. The battery industry is quite misleading on what the term "deep cycle" actually means...

Here are a few links that may help the battery buying decisions...

What Is A Deep Cycle Battery?

AGM Batteries Making The Choice

[jen1722terry]

Update on the battery issues with our CD 31:

After leaving the three dead batteries to the mercy of the 160-watt solar panel for two days, the starter (Grp 24 Deka AGM) registered 12.8 volts, while the two house bank units (Grp 31 Deka AGM) only registered 11.8 volts.

We finally were able to meet with the local marine electrician and he agreed with Maine Sail and Bob C that the batteries should be replaced.

The problem over the winter may have been a stuck float valve on the bilge pump along with the snow-covered solar panel. Surprisedly, the pump did not burn out, just ran down the batteries. We plan to switch out the pump with a spare we carry on board just in case.

We talked to several battery dealers in the Maritimes, and all agreed that the Deka batteries had a useful life of maybe 4 years with the heavy use we put them through on our last two long summer cruises, as well as our failure to run them down periodically.

After much thought, we decided to again go with quality AGMs (Odessey), rather than the less expensive flooded batteries. We did not consider Gel batteries because we're not familiar with them.

We're also curious why the solar panel controller would allow completely dead batteries to recharge - a possible safety issue, and we will pursue this with the controller manufacturer.

Again, thanks so much to Bob C. and Maine Sail for their very thoughtful comments.

Jenn and Terry

[Maine Sail]

Update on the battery issues with our CD 31:

After much thought, we decided to again go with quality AGMs (Odessey), rather than the less expensive flooded batteries. We did not consider Gel batteries because we're not familiar with them.

Jenn and Terry

Good choice. Odyssey's are a high quality, high acceptance rate AGM.

For the longest life of these expensive batteries you will want to adjust your absorption voltage up to 14.6V to 14.7V (preferably 14.7V) and feed them as much charge current as you possibly can. They prefer 40% of capacity as a minimum charge current for the longest life. You will also want temp compensation for your charge sources.... The Odyssey battery performed very well, coming in second place behind the Firefly, in the recent Practical Sailor PSOC testing in dealing with Partial State of Charge use.....

[Bob Ohler]

Another great example of why we are so fortunate to have Maine Sail watching the Cape Board! I frequently refer people to your "how-to" site!

Thanks Maine Sail!

[tjr818]

...Good choice. Odyssey's are a high quality, high acceptance rate AGM.

For the longest life of these expensive batteries you will want to adjust your absorption voltage up to 14.6V to 14.7V (preferably 14.7V) and feed them as much charge current as you possibly can. They prefer 40% of capacity as a minimum charge current for the longest life. You will also want temp compensation for your charge sources.... The Odyssey battery performed very well, coming in second place behind the Firefly, in the recent Practical Sailor PSOC testing in dealing with Partial State of Charge use.....

I know that our Pronautic Charger will automatically adjust the absorption voltage, but what can I do about our original alternator on our YSM8?

[David Morton]

I know that our Promariner Charger will automatically adjust the absorption voltage, but what can I do about our original alternator on our YSM8?

I use a Xantrex Digital Alernator regulator that has multistage output, adjustable for battery type, be it flooded, AGM, or Gel. I am currently set up for my Deka Gels with an absorption voltage of 14.1. And, btw, one of my house Gel batteries is over 10 years old and going strong. I am a Gel fan (Thank you, Sail Maine!).

David

[Maine Sail]

I know that our Pronautic Charger will automatically adjust the absorption voltage, but what can I do about our original alternator on our YSM8?

The Pronautic won't automatically set itself you need to set it for the absorption & float voltages that best match the Odyssey. If it is a Pronautic "P" model I would recommend the custom settings option.

As for your alternator you could convert it to external regulation and add a Balmar ARS-5 or MC-614 external regulator properly programmed for Odyssey or upgrade the alt & regulator as a high performance package or leave is as is and just understand that it is not going to be an optimal charge source for the Odyssey AGM's. You will just need to accept that shorter battery life & longer charge times will be one of the consequences of using the stock alternator...

[jen1722terry]

Well, our three new Odessey AGM batteries were delivered and installed over here in Nova Scotia. You US folks would not believe how much they cost.

Now we have to learn how to preserve them. We already have a large, 160-watt solar panel hooked up to a Morningstar solar controller. I'll photo the other charger tomorrow.

Terms like "temperature compensated charging" and "equalization charging" are new to us. Not sure if the latter applies to Odessey batteries. Much to learn and any any detailed advice will be profoundly appreciated. We're neophytes to the AGM fraternity, and wish to do it right.

Happy Solstice Sailing, and a late Happy Father's Day to all you Dad's GrandDads, Great GrandDads, etc.

J&T

[Paul D.]

J&T,

For this sort of advice, looking at a systems approach to how you use your power and figuring out simple solutions, I recommend calling Ham Ferris at Hamilton Ferris. They sell/design solar, wind systems and components for marine and off the grid applications. After looking at several options from a bunch of sources, I utilized his suggestions when I upgraded Femme's electrical systems in 2002 and they have served me well.

http://www.hamiltonferris.com

[Northoceanbeach]

Sorry man, I've been lugging to really big expensive gel batteries around for a year and a half trying to take care of them and waiting to learn how to install them(I did last week)

I would feel really bad for you, having lost your entire battery system, which it sounds like you cared about a lot.

[Northoceanbeach]

Sorry man, I've been lugging to really big expensive gel batteries around for a year and a half trying to take care of them and waiting to learn how to install them(I did last week)

I would feel really bad for you, having lost your entire battery system, which it sounds like you cared about a lot.