Gassing

pianotuna wrote:
Hi,

To equalize the cells they needs must gas. Other than that, with sealed batteries voltage should be kept lower than the gassing voltage which is temperature sensitive.

I get that. My question is, "Can they be safely used indoors when not connected to a charging source?"

Hi,

To equalize the cells they needs must gas. Other than that, with sealed batteries voltage should be kept lower than the gassing voltage which is temperature sensitive.

TomG2 wrote:
Are you saying that they only give off gas when charging and in fact at higher voltages?

TomG2 wrote:

Are you saying that they only give off gas when charging and in fact at higher voltages?

Not exactly.

They only give off enough gas to be a problem when being charged at a HIGH rate.
At normal charging rates, the small amount of H and O generated will not cause a problem .......unless maybe there is a spark or flame within a couple of inches of the battery.

Once dispersed, neither H or O are dangerous.

If charged at a REALLY high rate, so that the electrolyte actually boils.....then Sulfuric acid fumes can be dangerous.

Best to use AGMs inside. Next best is sealed wet with a reasonably sized charger. Last is open wet with a small charger but that option really is not recommended.

SidecarFlip wrote:
The gas both ways, charge and discharge. Chemical reaction.

The discharge has the SG and voltage going down together, but on recharge there is "SG Lag" which AFAIK is related to gassing somewhat.

Not too clear on how that all fits.

In the TC with its not much to outside vented battery box under the step up to the bed in front, the Wet batts on converter Float 13.6 kept making the LP alarm go off. I put in AGMs to cure that. Lately after moving the AGMs to the Class C, I have a sealed Wet in the TC on converter Float and it does not set off the LP alarm.

(I figure the LP alarm is sensitive to battery fumes as well as propane. Other fumes too according to reports on here about that.)

However, that may not answer the OP about safety, since the LP alarm is not a human and may have different standards for what is acceptable wrt battery fumes.

pianotuna wrote:
The sealed jars are valve regulated. If the pressure becomes too high they vent. Hence the need to stay just below the gassing voltage, when recharging.

Are you saying that they only give off gas when charging and in fact at higher voltages?

So how can you recharge them to full without reaching gassing voltage? They are not AGMs.

The sealed jars are valve regulated. If the pressure becomes too high they vent. Hence the need to stay just below the gassing voltage, when recharging.

What is the gas emission story on Wet, sealed batteries VS Wets with removable caps?

The gas both ways, charge and discharge. Chemical reaction.