Should My Batteries Be Gassing??

[Alan Wheeler]

if I want to vent by natural means (no fan), I would have to run a pipe up through the entire place to the roof

Actually it doesn't need to be even that complex. Hydrogen will very easily escape through any ventillation you have for your noram living. And at only 30PPM, it is not an issue anyway. I assume you have good ventillation as otherwise the living area will get damp and musty along with the windows misting up.
The only danger I see with not venting batteries outside, is in the uncommon instances of a major failure that has caused a battery to boil. Then you will wish you had them vent outside. Honestly, you would think some little fury animal crawled into a corner somewhere and died. It stinks. Certainly having at least some vents in the battery storage space to outside would help in such a situation. Even if that was in the floor of the space. If the storage compartment was near one wall, then a very simple external vent in the wall and a few simple holes in the floor would add plenty enough air flow.

[hellosailor]

"Or... if I seal the battery compartment off air tight, maybe the slight pressures involved when the gas is generated would help push it along a less than perfect vinyl tube route?" If it is a sealed compartment, the hydrogen will vent out the tube. Some may stay inside, depending on relative pressures, but that shouldn't matter. If you ran two tubes out of the box, one upwind and the other downwind, then you'd get differential pressure and the box would be scavenged.

But hydrogen is funny stuff, give it time and pressure and it even diffuses through solid stainless steel. (Which is why deep divers breathing trimix need special hydrogen vents in their watches--or the watches can blow up, well, burp<G>, during decompressions.)

[senormechanico]

Hmmm, put a hydrogen producing big heavy item in a nearly airtight box with electric wires capable of lots of energy transfer and the possibility of producing a spark running in and out of said box...sounds like a bomb to me!

Steve B.

[ssullivan]

Seniormechanico - isn't that what they do in boats? Batteries are in boxes or in small compartments (usually in the bilge) below the cabin sole with electrical cables and energy transfer. I am not seeing the difference... ??

But to follow up on the post:

Rick's info was right. The extra gassing (measured in PPM in my air, not by any rapid "boiling" in the battery) has slowed down tremendously.

The batteries seemed to have needed a couple days at 1.5 amps charging current to fully charge. Now, the batteries have dropped to .5 amp charging current and the PPM false reading on my CO meter is down to 10 PPM or zero PPM.

The amount of gassing is reduced greatly.

Thanks for all the input.

[Alan Wheeler]

It is quite possible for a battery to slowly disapate the bubles well after that charge has ceased. It is only the bubbles left clinging to the plates slowly breaking free. Nothing actually to do with charge. Although the majority of bubbles are shooting to the surface under charge, stopping the charge does not stop the bubbles imediatly.

[Extemporaneous]

Originally Posted by ssullivan

Seniormechanico - isn't that what they do in boats? Batteries are in boxes or in small compartments (usually in the bilge) below the cabin sole with electrical cables and energy transfer.

I'm looking for a good place to put lots of Batteries. As low as possible would be very good.
Can I indeed put them in the bilge?
Of course I would keep the bilge as dry as possible but it could get a couple of inches of water in it now and again.
If I was to make a long narrow battery box of fiberglass that would have a gasketed seal on the top and sit it just below the sole, leaving 2 or 3 inches below the box, would that be okay?
I also think a small vent on either side of the box and with hoses running one to either side of the boat providing cross ventilation would be a great idea. I think the general consensus is to only have one house bank of batteries. Would it be acceptable to split the physical location of some of batteries in the bank so part of the bank was in the bilge and the other part was higher?
They would be wired as one bank but could be split electrically if necessary. This way they could normally operate as one bank but you could isolate the lower batteries if they became submerged.

Scary question.
What would happen if 6 good sized 12v batteries (wired in series) were to be suddenly submerged under water?
Do they explode?
Would it depend on the load on the batteries at the time?
Would a fiber glass box contain the explosion?

On a little different battery note, if all your house batteries are deep cycle and your starting battery is a regular battery, does it not screw up the starting battery when you are setup to charge the majority of your batteries which are deep cycle batteries?

Any insights would be appreciated.
Extemp.

[hellosailor]

"Can I indeed put them in the bilge?"
Yes, but unless they are sealed AGMs, any contamination of battery acid and seawater liberates chlorine and eats the lungs, eyes, and flesh of anyone onboard.

"If I was to make a long narrow battery box of fiberglass that would have a gasketed seal " Battereies, even sealed ones, expand and contract. Unsealed ones breath as they charge and discharge, so your box will need to withstand that pressure across the seal, or accomodate it.

"I also think a small vent " that's mainly to discharge hydrogen during venting, even one will do. Anyone smoking near the vent make get a surprise.

"one house bank of batteries. Would it be acceptable to split " You do what you need to satisfy your design criteria. If you are going to split the bank, you either need heavy connections, or you are back to two banks. Which can work perfectly well if you manage them to the same discharge points.


"Do they explode? " Only on television. Depending on the charge state and the saltiness of the water, there should be some burbling and bubbling and you might see the green chlorine gas coming out, or more likely not see it as it went into solution in the water.

" does it not screw up the " Mixing any kinds of batteries and charge controllers can screw things up. There are a lot of battery threads in the forum messages, most go over the options and compromises.

[Extemporaneous]

Originally Posted by hellosailor

"Can I indeed put them in the bilge?"
Yes, but unless they are sealed AGMs, any contamination of battery acid and seawater liberates chlorine and eats the lungs, eyes, and flesh of anyone onboard.

Better make sure that I check this out some more. Are we talking say, one cup of sea water and the entire boat is filled or is this if your face is close to it? Just trying to get a sense of the extent.

Originally Posted by hellosailor

"If I was to make a long narrow battery box of fiberglass that would have a gasketed seal " Battereies, even sealed ones, expand and contract. Unsealed ones breath as they charge and discharge, so your box will need to withstand that pressure across the seal, or accomodate it.

The seal would only be so if the water raised in the bilge, it could not get into the battery box. The vent lines would equalize the pressure or that's the thought.

Originally Posted by hellosailor

" does it not screw up the " Mixing any kinds of batteries and charge controllers can screw things up. There are a lot of battery threads in the forum messages, most go over the options and compromises.

Could the right AGM battery survive as a starting battery?

Thanks for your reply, it's helpful.
Extemp.

[hellosailor]

""Are we talking say, one cup of sea water and the entire boat is filled "
Dunno. I can tell you that if you take a kitchen pot, pour in one cup of nice fresh ammmonia, and one cup of nice fresh bleach...you're going to evacuate the kitchen in fast order. I never experimented on batteries, and "one whiff" of chlorine is enough to destroy lung and throat and nasal tissue, so why bother experimenting?

"The seal would " Seals are great, as long as they work. Ever met one that leaked? Got a grain of sand in it?


"Could the right AGM battery survive as a starting battery?" Sure are AGM SLI batteries, AGM deep cycle batteries, AGM dual purpose batteries. As long as the load is matched, an AGm deep cycle will work fine. But the purpose of the starting battery is to have it isolated--so when you rock out on Aerosmith (or Tchaikovski) and run down the house bank, you can still restart.

Some folks think AGM don't hold up in the long run. Others say they just have to be charged differently. (True.) Everyone agrees they'll cost you about 1/3 more than wet lead, but that also means no acid problems. And the extra cost? $25 for a shirt, $25 for a pair of jeans, $100 for a jacket....it can balance out too.<G>

You'll find lots of threads, here and on the web, about it.