Battery's left in boat ?

[fluxcore]

Last year I pulled my batteries from my boat to over winter in the house and this year I have a wired garage so i decided to leave them in and do some intermittent charging over the winter. Any pros / cons doing this? Their new interstate batteries, very expensive to replace. I have a HUGE furness in there to but decided to save some money and keep it off lol

[HunterDave]

As long as they don't freeze you should be okay but if your boat is in the garage anyway why not just take it out and put it in the basement to be safe?

[big zeke]

Most lead-acid batteries will discharge completely if left sitting directly on concrete over the winter. If you have deep cycles they should recharge and be fine but anything else could cause problems. I pulled mine this fall and have them on some 2X4s in the garage. I put the trickle charger on them for about a day once a month, the tester shows full charge. When they are on the boat I have a solar panel that keeps them topped up 24/7.

I learned the hard way, for starting batteries, keep them charged up and they last a long time, completely kill them often and they will give you lots of grey hair.

Zeke

[bentley]

Most lead-acid batteries will discharge completely if left sitting directly on concrete over the winter. If you have deep cycles they should recharge and be fine but anything else could cause problems. I pulled mine this fall and have them on some 2X4s in the garage. I put the trickle charger on them for about a day once a month, the tester shows full charge. When they are on the boat I have a solar panel that keeps them topped up 24/7.

I learned the hard way, for starting batteries, keep them charged up and they last a long time, completely kill them often and they will give you lots of grey hair.

Zeke

I have always though the same about concrete & batteries , but have been told it's not true , concrete will not discharge them . If its possible , just remove them to keep them from freezing . Place the batteries on a 2 amp charger every month or so for a day . It has worked for me for many years .

[Xiph0id]

Concrete and battery myth is just that a myth.

[bloopbloob]

Concrete and battery myth is just that a myth.

+1

[gramps73]

Flex
If you leave them in your boat and have them plugged in they will be fine.

[gunnargsd]

Concrete and battery myth is just that a myth.

X3. I was an auto tech for many years and would hear the old timers say this over and over. No one could ever explain why nor have I found any research that supports this myth. Even the instructors at SAIT could not give a valid reason other than thats what they been told.

I don't have boat batteries but I do have RV batteries, I take them out and they are inside covered up. I charge them at least twice maybe three times over the winter and they have lasted just fine.

[Wild&Free]

Its probably not the concrete itself that drains the batteries but getting cold since concrete is such a great insulator.

[thorne]

X3. I was an auto tech for many years and would hear the old timers say this over and over. No one could ever explain why nor have I found any research that supports this myth. Even the instructors at SAIT could not give a valid reason other than thats what they been told.

I don't have boat batteries but I do have RV batteries, I take them out and they are inside covered up. I charge them at least twice maybe three times over the winter and they have lasted just fine.

I actually did find the scientific reason why this happens...just wish I could find the literature....so it technically is not "concrete" which causes this it will occur on any cold surface. What happens is the electrolyte will separate due to the temperature variation of the air and the cold floor. So if the floor surface is a few degrees colder then the surrounding air the electrolyte will have temperature variations which cause separation, or a like effect, and thus rendering the battery useless. So having a insulating layer between concrete and the battery helps to stabilized the unused batteries internal electrolyte temperature. It doesn't matter what that temp is, it has to be constant.

As for leaving your fully charged batteries in the boat...well we finally know what is going to cause the end of the world Friday!

[AxeMan]

I actually did find the scientific reason why this happens...just wish I could find the literature....so it technically is not "concrete" which causes this it will occur on any cold surface. What happens is the electrolyte will separate due to the temperature variation of the air and the cold floor. So if the floor surface is a few degrees colder then the surrounding air the electrolyte will have temperature variations which cause separation, or a like effect, and thus rendering the battery useless. So having a insulating layer between concrete and the battery helps to stabilized the unused batteries internal electrolyte temperature. It doesn't matter what that temp is, it has to be constant.

As for leaving your fully charged batteries in the boat...well we finally know what is going to cause the end of the world Friday!

Bingo! Thorne, I am impressed. You pass.

All the others that say the concrete - battery storage phenomenon is a myth are wrong. I taught a battery technology lab at NAIT for quite a few years.

Here is what I wrote in another thread a long time ago:

Okay guys, here is the truth on the concrete floor and battery phenomenon. When a battery is placed on a concrete floor, the floor is generally colder than the air temperature in the garage. It will act like a heatsink and cause the bottom of the battery to become slightly cooler than the top. This temperature variance will stratify the electrolyte slightly with the denser (greater specific gravity) electrolyte sinking to the bottom of the cells. With a difference in the specific gravity within the electrolyte from the top of the cell to the bottom, a potential voltage difference is set up from top to bottom and thus a self discharge current flows within the cell. When a lead acid battery is stored in a discharged state, the PBSO4 that forms on the plates will change from a soluble slime to a crystalized hard non-soluble structure if the battery is left uncharged for months on end. Charging the battery moves the SO4 ions back into electrolyte as H2SO4 (sulfuric acid) and the plates will be free of the lead sulfate slime. This crystalizing phenomenon is known as battery sulfation which is a non-recoverable state. Once level 3 bonds are formed over time in the lead sulfate there is no breaking them no matter how much you charge the battery. There are desulfation compounds that can be added to batteries to help prevent this. EDTA (ethylenediaminetetraacetic acid) is one such compound but a batteries plates must be treated with it prior to being filled with acid as it is non-soluble in an acidic solution.

Morel of the story: Storing a battery on a concrete floor will cause faster self discharge and a battery stored in a discharged state will sulfate. Keep your batteries charged and stored properly.

http://www.outdoorsmenforum.ca/showthread.php?t=77693&highlight=battery

[thorne]

Bingo! Thorne, I am impressed. You pass.

All the others that say the concrete - battery storage phenomenon is a myth are wrong. I taught a battery technology lab at NAIT for quite a few years.

Here is what I wrote in another thread a long time ago:

Okay guys, here is the truth on the concrete floor and battery phenomenon. When a battery is placed on a concrete floor, the floor is generally colder than the air temperature in the garage. It will act like a heatsink and cause the bottom of the battery to become slightly cooler than the top. This temperature variance will stratify the electrolyte slightly with the denser (greater specific gravity) electrolyte sinking to the bottom of the cells. With a difference in the specific gravity within the electrolyte from the top of the cell to the bottom, a potential voltage difference is set up from top to bottom and thus a self discharge current flows within the cell. When a lead acid battery is stored in a discharged state, the PBSO4 that forms on the plates will change from a soluble slime to a crystalized hard non-soluble structure if the battery is left uncharged for months on end. Charging the battery moves the SO4 ions back into electrolyte as H2SO4 (sulfuric acid) and the plates will be free of the lead sulfate slime. This crystalizing phenomenon is known as battery sulfation which is a non-recoverable state. Once level 3 bonds are formed over time in the lead sulfate there is no breaking them no matter how much you charge the battery. There are desulfation compounds that can be added to batteries to help prevent this. EDTA (ethylenediaminetetraacetic acid) is one such compound but a batteries plates must be treated with it prior to being filled with acid as it is non-soluble in an acidic solution.

Morel of the story: Storing a battery on a concrete floor will cause faster self discharge and a battery stored in a discharged state will sulfate. Keep your batteries charged and stored properly.

http://www.outdoorsmenforum.ca/showthread.php?t=77693&highlight=battery

Well golly gee wizz......maybe momma didn't raise no unedumacated bastard after alls....

On another note....I'm pretty sure I just remembered where I read that explanation in the first place....:medium-smiley-035:.Thx Axeman!

[AxeMan]

The electrolyte temperature stratification phenomenon (and resulting self discharge) was observed in second world war submarines. The banks of batteries rested directly on the cold steel floor of the subs in some designs and the ambient air temperature was kept much higher for the benefit of the mariners. This was an extreme case of heatsinking on the bottom of the batteries and caused them trouble until they figured out that an insulation layer was required between the batterry and the colder floor.

Note: A large temperature difference between the floor and ambient air temperature must exist for the increased self discharge to take place. An unheated garage with a concrete floor probably would not increase the natural self discharge rate.

Another neat example of electrolyte stratification is when you crank your car battery down until it will no longer crank and just clicks the starter relay. Let it sit for a few minutes and it will crank again for a bit. What is actually happening is that the heavier specific gravity electrolyte that was above the plates now sinks into the lesser specific gravity electrolyte that was just reduced by the cranking process. This now gives the battery a bit of a boost because more H2SO4 is now in contact with the lead plates allowing for more electro-chemical conversion.