Will batteries last 11-12 months on the hard?

[kerk fisher]

We have two battery banks: house with four 6 volt and a 12 volt starting bat. After disconnecting and topping off our batteries with a full charge last Sept. 1 and putting her on the hard outside in Southern Lake Huron (Penetanguishene) we returned home to Kentucky (12 hours away). Because of various situations here, we will be returning to our boat later than we thought, perhaps as late as August or Sept.

Normally we leave our batteries for 10 months (August 1 to June 1), and they're OK.  My question is, after 11-12 months will the batteries be OK? If not, what should I do? And, this is extreme, Is it possible we might have battery acid all over from a crack? If so, how is it cleaned up?

[Jon Schneider]

Use ammonia to clean up any spills; it'll create an inert ammonia sulfate residue as a result of neutralizing the acid. 

The answer to your question regarding time left uncharged is that to a certain extent it depends on the age and condition of your batteries; the older they are, the more detrimental this treatment will be.  Nevertheless, it's bad no matter what.   That said, you say that they don't suffer from being left for 10 months, so how much worse will an extra two months be?  Actually, it might be quite a bit worse, because it comes during the warmest months when the battery self-discharge rate is highest.  Too bad you can't sneak up north and rig a solar panel with a trickle charger.  Alternatively, you might want to invest in one of those Pulsetech battery re-conditioners; I don't know if they actually work, but it might be worth a try. 

[Marshall Tonner]

Kerk, we have had no extreme temperatures in the area and battery casings are a pretty durable item so I doubt that leakage will be a problem.If, when you return, you need help testing or replacing your batteries feel free to contact me here or at Doral Marine in Midland. I normally stock 6 volt batteries in my service van and can do much better than yacht pricing.
                   Marsh Tonner

[Stu Jackson]

Rest easy, Kerk.  I think Jon nailed it when he said, "what's an extra two months?"  You could calculate the self discharge rates, but, when all is said and done, if you've fully charged them before you left and they've been working fine for you in the past, the extra two months is NOT that much longer.

In a related, "Why Worry, Be Happy" vein, what can you do about it now, from where you are, and from this thread, that woudl change anything?  Just being philosopical...

[Ken Heyman]

Kerk,

I also keep my 4 Trojans onboard through a midwest winter. I get down every 6 weeks or so- to charge them and check the electrloyte. You don't want your plates to be exposerd as it is my understanding that this will freeze or kill the battery quite readily or at the very least it will suffer a loss of capacity.

I'm close to the yard and understand you're 12 hours away. --Is there anybody at your yard that could do these chores for you. I guess as always it's only money.

Good luck,

Ken

BTW--when I use spell check, I have lost my content ----anyone-else having this problem? I'm out of town and perhaps it is server related. This reply is being sent without using that utility. I spoke to Stu earlier who has dsicovered a better spell check and perhaps the site it has already been posted.

Ken

[Stu Jackson]

I found the spell check somewhat clunky, so we use iespell.  Do a google on it and download the app.  It's free and works easily with a right click to check spelling on web pages.

[Bill Asbury]

Kerk, while I'm certainly no authority on the subject, it's my understanding that batteries get sulphated over time if not kept charged and if electrolyte is allowed to go below plate level, resulting in the batteries having reduced capacity of perhaps 50% or less.

The solution for you would seem to be having someone, friend or yardworker, put a full charge in your batteries and then leave a trickle charger hooked up.  Since that seems obvious, perhaps it isn't feasible where your boat is located.

I also have 4 Trojan 105 golf cart batteries in the house bank and a separate starting battery.

BTW, I noticed that your hull #1102 and year 1992 are out of sync so I'm guessing one or the other is a typo.  My C34 is hull #1140 and year 1991.

Best wishes,
Bill Asbury

[Ron Hill]

Kerk : You've received some good advice for the future.  I believe what you should do is call your yard and ask them what they would be willing to do to keep your batteries up. 
They may even have a heated battery storage area!   

[kerk fisher]

Thank you all for your help. I've been out of town, travelling and haven't gotten back to the web site. I am on it and look forward to another sailing season. Kerk

[lazybone]

Use ammonia to clean up any spills; it'll create an inert ammonia sulfate residue as a result of neutralizing the acid. 

The answer to your question regarding time left uncharged is that to a certain extent it depends on the age and condition of your batteries; the older they are, the more detrimental this treatment will be.  Nevertheless, it's bad no matter what.   That said, you say that they don't suffer from being left for 10 months, so how much worse will an extra two months be?  Actually, it might be quite a bit worse, because it comes during the warmest months when the battery self-discharge rate is highest.  Too bad you can't sneak up north and rig a solar panel with a trickle charger.  Alternatively, you might want to invest in one of those Pulsetech battery re-conditioners; I don't know if they actually work, but it might be worth a try. 

Jon,
Could you point me to some reference information that would confirm; higher temps accelerate self-discharge.  I know for dry cell batteries it's the opposite, but I can't find any info about the effects of temperatures on wet cells?

[Stephen Butler]

Could have it all wrong, but I have understood for decades that batteries are controled redox chemical reactions, and with very few and exotic exceptions, the speed of chemical reactions occure as a function of temperature (amoung other conditions).  The warmer the chemicals, the fast the reaction, or so my chemistry books say.

[jmnpe]

There is a basic rule of thumb for almost everything electrical, including battery self-discharge rates. With each increase in temperature of 10 degrees C, everything that you wish wouldn't happen doubles it's rate.

In the northern climates, self discharge of batteries in good shape over the winter will probably not be a quick killer. In the southern climates ( like Texas... ), wet cells need a full recharge about every 60 to 90 days during the "cold" months ( < 50 degrees ) to prevent a permanent loss of capacity. During the hot months ( > 85 degrees ), the full recharge needs to happen about every 30 to 45 days to prevent a permanent loss of capacity.

Flooded batteries don't loose water from the electrolyte unless they are charged above their gassing point of about 13.8 volts, or unless the ambient temperature is very high ( > 100 to 110 degrees ). If they are just sitting in a northern climate, nothing will happen to the electrolyte level over the winter.

Exposed battery plates in flooded cells become "dead" after being dried out and exposed to oxygen for more than about 48 hours. "Dead" sections of plates produce a permanent loss of battery capacity that cannot be recovered by pulse charging techniques or most anything else.

Almost any form of "trickle charger" can damage batteries over a storage period unless it provides a well regulated output voltage below the gassing voltage. Any type of continuous charging of a battery, even at "float" voltages, will produce long term damage to the battery in the form of positive grid corrosion. It won't completely "kill" the battery, but it will reduce its capacity and increase its internal resistance. The longest useful life of any battery will be realized by utilizing cycle charging: only charge the battery when it needs it, fully recharge the battery at every charge, and then leave it alone in between charges.

If a boat is going to be on the hard for a full year in almost any US climate, the best way to not damage the batteries is to remove them from the boat and take them some place where they can be fully recharged on the intervals mentioned above. Nobody will care as much about your batteries as you, the owner, will.

If the batteries have to be left unattended, the best you can do is to make sure the cells are all properly filled to about .5 inch above the top of the plates by topping off with distilled water. Then, fully charge them per manufacturer's instructions, followed by an equalization charge per the manufacturer's instructions. Finally, recheck the electrolyte levels and top off with distilled water if required. Disconnect all loads from the batteries ( remove the connections ) and make sure the tops of the battery cases are clean between the battery terminals to prevent external discharge paths.

Just some facts for your consideration.

John

[Ken Juul]

I was always told the danger of leaving batteries in the boat over the winter was the possibility of freezing, cracking the case, then acid clean up and associated repairs when things thawed.  The key to not having the electrolyte freeze is to keep them charged.  I found this info on several different battery company web sites. 

State of Charge Specific Gravity ~ Approximate Battery Voltage
100% charged 1.265  ~ 12.6v or greater
75% charged 1.239  ~ 12.4v
50% charged 1.200  ~ 12.2v
25% charged 1.170  ~ 12V
Fully discharged 1.110  ~ 11.7 or less

Specific Gravity(cor.to 80oF/26C) Freezing Temp
1.280 Spec. Grav.(cor.to 80oF/26C) -92F (-69C)
1.265 Spec. Grav.(cor.to 80oF/26C) -72.3F (-57.4C)
1.250 Spec Grav.(cor.to 80oF/26C) -62F (-52.2C)
1.200 Spec Grav.(cor.to 80oF/26C) -16F (-26.7C)
1.150 Spec. Grav.(cor.to 80oF/26C) +5F (-15C)
1.100 Spec. Grav.(cor.to 80oF/26C) +19F (-7.2C)

So according to the data a fully charged battery should be safe until -72*F, which I hope no one ever sees.  A battery at 50% charge is -16*F, some of our members may see that.  It gets dicy at about 25% charge, batteries can freeze at temps above 0*F.  Moral of the story, keep the batteries charged as has been suggested by everyone else.