Properly Securing Batteries

[JPA Cate]

The way I understand the need for venting, it has to do with H2S being released during equalization charging. That gas is odorless, colorless, and can kill you. If this is incorrect, I'd like to have someone who really understands what happens explain that.

The need for containment of electrolyte is because (with flooded lead/acid batteries) sulfuric acid (H2S04) can eat the heck out most everything, including your skin.

Ann

[hellosailor]

Ann-
Batteries can also vent hydrogen during charging, which creates a risk of explosion. But the normal corrosive vapors are well established. They ate the trunks of old Fiats (124 series?) enough so that Mazda used a sealed AGM in their sportsters instead. And BMW still puts wet lead in the X3/X5, but they use a vent hose to direct the vapors out of the "trunk".

Of course if your battery cycling is not particularly energetic and your boat is well ventilated...maybe the battery gasses will just help discourage mildew onboard.(G)

The chlorine hazard is by far the least likely, but if you've ever seen a chemical fog creeping towards you in a confined space...there's no maybe about what will happen if that one catches you.

[colemj]

H2S should not be released during an equalization charge. It definitely is not odorless - it smells strongly of rotten eggs. Yes, it is poisonous.

If H2S is being released during any charging regime, the battery/cell is damaged or quickly being damaged by a severe overcharge. It requires a hot battery/cell accepting damaging amounts of current to be produced. Usually, this also involves a dry cell.

H2S is heavier than air, so any passive venting (unless through the bottom of the box) will not help.

General question to everyone: How many boats do you know with batteries vented into the living spaces which have experienced explosions or injuries/deaths from fumes?

Mark

[hellosailor]

Mark-
"General question to everyone: How many boats do you know with batteries vented into the living spaces which have experienced explosions or injuries/deaths from fumes?"
I suspect each of us knows far more car owners than boat owners. And yet, the odds are good that none of us knows any of the 10,000+ folks who had a battery explosion while charging or jumpstarting their cars in every typical year, in the US alone. (Which is why more places are selling goggles bundled in with the jumper cables & kits these days.)

I've never met anyone who knew anyone who actually had a propane or natural gas explosion, either. But they keep taking buildings down every year as well.

Odds of any of this happening to any of us? 50-50. Statistics be damned, either it does happen, or it doesn't, and that's 50-50 to me.

[boatpoker]

Originally Posted by Flying Knight

So are boxes required by the standard? Just looking at it I don't see why the storage space couldn't meet the standard while ditching the boxes. Any exploding batteries would be contained within, there just needs to be a lining in the entire compartment that will handle the leaking electrolyte. What am I missing?

Sent from my Nexus 10 using Tapatalk

Boxes are not specified, just a means to contain spilled electrolyte. Plywood trays does not cut it.

[Flying Knight]

Originally Posted by boatpoker

Boxes are not specified, just a means to contain spilled electrolyte. Plywood trays does not cut it.

I've been trying to determine a proper lining for the compartment, could I lay in polyethylene sheeting to contain any spills?

Sent from my Nexus 5 using Tapatalk

[colemj]

Originally Posted by Flying Knight

I've been trying to determine a proper lining for the compartment, could I lay in polyethylene sheeting to contain any spills?

Sent from my Nexus 5 using Tapatalk

Polyethylene sheet is probably not the easiest way to contain spills, but could you glass over the box area you have with some resin and 4-6oz cloth?

Mark

[Flying Knight]

Originally Posted by colemj

Polyethylene sheet is probably not the easiest way to contain spills, but could you glass over the box area you have with some resin and 4-6oz cloth?

Mark

My only issue with that is there are wire runs in the compartment, so everything needs to be able to be removed in case I need access.

Sent from my Nexus 5 using Tapatalk

[colemj]

Originally Posted by hellosailor

Mark-
"General question to everyone: How many boats do you know with batteries vented into the living spaces which have experienced explosions or injuries/deaths from fumes?"
I suspect each of us knows far more car owners than boat owners. And yet, the odds are good that none of us knows any of the 10,000+ folks who had a battery explosion while charging or jumpstarting their cars in every typical year, in the US alone. (Which is why more places are selling goggles bundled in with the jumper cables & kits these days.)

I've never met anyone who knew anyone who actually had a propane or natural gas explosion, either. But they keep taking buildings down every year as well.

Odds of any of this happening to any of us? 50-50. Statistics be damned, either it does happen, or it doesn't, and that's 50-50 to me.

Jumpstarting a dead starting battery from a charging battery is not applicable here. I know you know why.

Propane and natural gas explosions are also not applicable because of the massive difference in the gases and their physical and chemical behaviors.

Yes/No are not the odds of any of this happening, so are not 50%. That is just bad statistics and reasoning. Using your reasoning, there is a 50% chance you will die from ebola tonight. Do you feel lucky?

Mark

[colemj]

Originally Posted by Flying Knight

My only issue with that is there are wire runs in the compartment, so everything needs to be able to be removed in case I need access.

Sent from my Nexus 5 using Tapatalk

OK, how about making a thin container out of fiberglass? When you need access, you remove the batteries and lift out the light container? Look around and you may find something appropriate that fits.

Mark

[Downline]

Originally Posted by Ann T. Cate

The way I understand the need for venting, it has to do with H2S being released during equalization charging. That gas is odorless, colorless, and can kill you. If this is incorrect, I'd like to have someone who really understands what happens explain that.

The need for containment of electrolyte is because (with flooded lead/acid batteries) sulfuric acid (H2S04) can eat the heck out most everything, including your skin.

Ann

H2S is a naturally occurring gas in crude oil and natural gas. Some areas we do diving work in, you walk around with H2S monitors all the time. It's a heavy gas and you run for the bridge when you hear an alarm. Even very low concentrations smell like rotten eggs and can kill you. It's also a by-product of human and animal waste. I don't think that your batteries will produce it. Some industrial activities like refineries will produce it as a by product.

[belizesailor]

Originally Posted by hellosailor

belize-
"Other than eletrolyte containment, ...except for being vented outside "

If you take on sea water and if gets into the batteries, chlorine gas will be released. Which will promptly chew out the eyes and lungs of anyone anywhere that it is vented to.

So...unless you've got sealed batteries, venting *outside* the hull could be a good thing. Just in case the ocean gets to the batteries.

Sealed batts on the bridge deck of a cat...sea water ingress highly improbable.

Typical battery boxes are not water tight anyway so would not prevent this.

My start batts are in boxes, fully enclosed, but certainly not water tight.

[belizesailor]

Originally Posted by hellosailor

Mark-
"General question to everyone: How many boats do you know with batteries vented into the living spaces which have experienced explosions or injuries/deaths from fumes?"
I suspect each of us knows far more car owners than boat owners. And yet, the odds are good that none of us knows any of the 10,000+ folks who had a battery explosion while charging or jumpstarting their cars in every typical year, in the US alone. (Which is why more places are selling goggles bundled in with the jumper cables & kits these days.)

I've never met anyone who knew anyone who actually had a propane or natural gas explosion, either. But they keep taking buildings down every year as well.

Odds of any of this happening to any of us? 50-50. Statistics be damned, either it does happen, or it doesn't, and that's 50-50 to me.

I knew one person who died in a propane explosion aboard a boat. Know of a number of more minor propane accidents on boats.

Never even heard of an explosion aboard a boat from off gassed hydrogen. So, I suspect the odds are way less than 50/50.

Did manage to blow a battery up in a car once due to spark + hyrdogen from old battery in bad condition. It was a little startling, but nothing life threatening.

[Zil]

Hydrogen sulfide paralyzes the odor receptors. Low concentrations smell bad, high concentrations do not smell but do kill. High concentrations also explode.
Chlorine gas is formed from salt through electrolysis. Takes a lot of energy. Salt water shorting a battery bank would drain the battery before any large quantity of chlorine gas would be generated. More of a corrosion problem than a cause of death.
I have seen batteries explode due to spark while charging. The shrapnel and fog of acid is not nice.

[colemj]

Regarding jump starting (which has nothing to do with the question of venting here) - it would be very rare indeed if a battery exploded due to external hydrogen gas release while jump starting it.

To release hydrogen gas, that battery has to be at a voltage greater than 14.2V. Batteries being jump started are, by definition, not at that voltage.

The most common reason for explosions is because the bad battery is usually such due to an internal short or very high internal resistance. When one then quickly dumps a load of current into it from a good battery, the short or high resistance either creates those hydrogen/oxygen gasses internally and an internal spark ignites them, or the rapid heat buildup throughout the electrolyte bursts the case through pressure.

So you can see why that situation has little to do with normal, routine gassing from charging of good batteries. In the case of a bad battery being hit by a high current source, an external vent is not going to help any, as the explosion will be internal to the battery. A container would be helpful at this time.

Mark