Dead batteries--can they be revived?

[Joe Myerson]

I finally got down to the boat this weekend, where I discovered the joys of seacock maintenance (thanks, Neill, for the Morey's Red!), replaced the thermostat and some fasteners for the seawater pump on my 1GM and made a distressing discovery: It appears that my batteries, which I stored on the boat this winter, have died.

(Yes, all of you who warned me about trickle chargers from Harbor Fright may have been right. The chargers that I bought should probably have been hooked up for a long time, but the owner of the lot where my boat is stored didn't want me to leave them charging overnight.)

When I put the boat on the hard, the batteries read something like 12.75 volts each. When I tested them today with my Radio Shack digital multimeter, I got readings of 1.95 v (battery 1) and 6.54 v (battery 2).

The batteries are Exide Nautilus Gold Deep Cycle NG-24 batteries. These are sealed batteries.

So here's my question: Is it possible to put a charge back into these batteries--or should I just buy new ones? My boat is stored directly behind an auto repair shop, so I'm assuming they have the equipment that could recharge the batteries, assuming they can be saved.

This year I'm at the low end of a steep learning curve, and I'm afraid the batteries are the first casualty. I shudder to think what will happen when I de-winterize my engine!

Thanks, as always,

--Joe

[Russell]

Wow, readings that low are drastic, assuming you left the batteries disconnected through the winter so they could not possibly take a load, my first inclination is that your multi meter is busted. Ask the yard or a friend if you can borrow another and check again.

If they are indeed that low, I doubt they can be revived, but its always worth trying. Take them home with you since the yard wont allow them to be plugged in overnight and put them on a charger.

Being sealed batteries you probably cannot equalize them, but some AGM manufacturers do actually recommend it, check with the people who made them and if they say its okay, then try it at whatever settings they recommend if normal charger does not work.

[Joe Myerson]

Russell,

I was kinda hoping that it might be the multimeter. I'll check that out first.

The batteries were disconnected from everything except the el-cheapo trickle chargers.

I had hoped to avoid removing the batteries and storing them at home because they're very heavy, in a difficult place to reach and my back ain't what it used to be.

Next year, rather than storing it in a lot (it's not a boatyard), I might have the boat hauled to my parents' yard, in which case I could keep the chargers connected, or run them once a month or something.

Like I said, I'm at the bottom of a steep learning curve.

--Joe

[Neil Gordon]

I shudder to think what will happen when I de-winterize my engine!

I just open the raw water intake and turn the key.

[tartansailor]

Hi Joe,
Doesn't look good.
Might consider buying a good charger from NAPA or Sears, one with a 3 stage charging regimen for about 80 bucks.
After they're fully charged and they hold a full charge (multimeter) for at least a week, then all is not lost.
A battery hydrometer from Ace Hardware for about 3 bucks would be ideal.
Hope they turn out well for you.
Dick

[Maine Sail]

Some cheap chargers can actually drain off a battery if left connected but unplugged from the wall. I don't know internally what causes this but I have seen it happen.

A disconnected battery should be truly disconnected from everything. Our wet cell bank sat on the boat this winter from Nov 29 to April 2 and still measured 12.64 volts when I re-connected them, or slightly over 90% SOC. They had no charge from Nov 29 to April 2. This is a pretty standard winter form my batts. Some years I top them up in Jan or Feb but this year I specifically did not.. Self discharge is considerably slower in colder temps.

I can only imagine your charger bleeds them if not connected to the wall....

The Nautilus Gold Deep Cycle series batteries should not be "sealed" and the caps should come right off and you should have access to top them up with water.. I have installed a bunch of them including a 345 Ah bank of NG-31's just last week. Caps come right off and I showed the customer how to check the electrolyte on them.

You can try charging them then have them load tested as you don't have much to loose. Unfortunately at that depth of discharge, assuming your meter is right, the likely hood they can be salvaged to a serviceable life is probably rather slim.

[Russell]

Hi Joe,
Doesn't look good.
Might consider buying a good charger from NAPA or Sears, one with a 3 stage charging regimen for about 80 bucks.
After they're fully charged and they hold a full charge (multimeter) for at least a week, then all is not lost.
A battery hydrometer from Ace Hardware for about 3 bucks would be ideal.
Hope they turn out well for you.
Dick

His batteries are sealed, the hydrometer wont help him.

[Joe Myerson]

Some cheap chargers can actually drain off a battery if left connected but unplugged from the wall. I don't know internally what causes this but I have seen it happen.

I suspect this is the cause of the problem, as the batteries metered close to fully charged when I put the boat to bed. Then I hooked up those two chargers from Harbor Freight. In defense of the chargers, they may have been designed to be connected all the time--who knows?

I can't say I wasn't warned.

But I guess I'll try to get them charged up. Unfortunately the boat is about 85 miles from where I live, and I'm not going to be able to get to it for a while.

Thanks, everybody, for the suggestions.

--Joe

[tartansailor]

Hi Joe,
Doesn't look good.
Might consider buying a good charger from NAPA or Sears, one with a 3 stage charging regimen for about 80 bucks.
After they're fully charged and they hold a full charge (multimeter) for at least a week, then all is not lost.
A battery hydrometer from Ace Hardware for about 3 bucks would be ideal.
Hope they turn out well for you.
Dick

His batteries are sealed, the hydrometer wont help him.

The Nautilus Gold Deep Cycle series batteries should not be "sealed" and the caps should come right off and you should have access to top them up with water

If a lead / acid battery were hermetically sealed; Where would the hydrogen gas go?::::BOOM!

Dick

[Joe Myerson]

His batteries are sealed, the hydrometer wont help him.

The Nautilus Gold Deep Cycle series batteries should not be "sealed" and the caps should come right off and you should have access to top them up with water

If a lead / acid battery were hermetically sealed; Where would the hydrogen gas go?::::BOOM!

Dick

I believe I could see vents in the batteries, but I did not see any filler caps. However, there might be a cover that comes up to reveal filler caps--unfortunately, I'm now 85 miles from the batteries.

--Joe

[I guess there are too many "quotes" within "quotes."]

[Joe Myerson]

I realize that my batteries were replaced after a storm surge flooded the battery-storage shed at my boatyard in December 2005. That makes them close to the end of their lives anyway, and renders it unlikely that I could bring them up to full charge and expect good future performance.

So, it looks like this discussion was largely academic.

Still, thanks for the advice.

Anybody want a pair of Harbor Freight trickle chargers? You pay the shipping and they're yours.

Thanks again,

--Joe

[Howell and James]

We thought our 6 year old batteries were dead. We took them to the nearest tyre/battery garage and asked them to test them. They said they were O.K. and told us to revive them by topping up the water and adding half a teaspoon of bicarbonate of soda to each cell! 'Seems to be working.

[Duncan]

We thought our 6 year old batteries were dead. We took them to the nearest tyre/battery garage and asked them to test them. They said they were O.K. and told us to revive them by topping up the water and adding half a teaspoon of bicarbonate of soda to each cell! 'Seems to be working.

I like those kinds of remedies! Thanks for a nice simple tip.

Does anyone here understand battery chemistry enough to explain why this would work?

[Joe Myerson]

We thought our 6 year old batteries were dead. We took them to the nearest tyre/battery garage and asked them to test them. They said they were O.K. and told us to revive them by topping up the water and adding half a teaspoon of bicarbonate of soda to each cell! 'Seems to be working.

I've already gone out and purchased two new deep-cycle, wet-cell batteries (and I'll be turning in the old batteries for a slight discount). However, it's good to know about these kinds of remedies in the future.

When I purchased my batteries (US Battery 24 TMX) from the only distributor in New England, we chatted about my incredibly low meter readings on the existing batteries. He said that the battery that measured 5.74v could probably be brought back. The other one (1.75v), he said was probably beyond redemption.

Thanks again for the tip. I always keep baking soda on the boat.

--Joe

[Neil Gordon]

... half a teaspoon of bicarbonate of soda ...

Joe,

Add the other half teaspoon to a glass of water, to cure your indigestion from battery aggravation.