Batteries putting off hydrogen

[fryewe]

A good basic discussion of charging flooded lead acid batteries is here...Lee Hart's Lead-Acid Battery Charging Basics.

Gassing occurs when cell voltage exceeds about 2.4 volts per cell at about 80F, or about 14.4V for a 6-cell (12V) battery, when being charged. This temperature dependent gassing voltage goes down as temperature goes up, as the electrolysis of the electrolyte is more rapid at higher temperatures, as is most chemical reactions.

[belizesailor]

Batteries in poor condition off gas more too. I actually managed to blow one up once due to an electical spark...definately got my attention...not a big bang, but did shatter the case...bits of plastic shrapnel and battery acid thrown.

[Alan Mighty]

I have to join zeehag, a64pilot, and sailorboy1 in urging you to solve the overcharging problem FAST.

Please realise that what you call hydrogen gas is really a mist of hydrochloric acid in aqueous solution and hydrogen gas. And you're cooking those batteries.


Acid vapours are a big industrial hazard. Humans working in acid vapour environments show particular health disorders. One of the simple ones is dental erosion. Every breath you take, every time you open your mouth, exposes you to acid vapour.


So you are flooding your cabin and aft berth room with acid vapour.


Stop it.


Before you vent that acidic vapour to your engine room, think about what it will do to your engine.


Get your inverter/charger, your alternator etc checked now. Add a charging regulator if that's what is needed.

[Kita]

Originally Posted by a64pilot

Fix the overcharging issue, and I think you will fix the H2 issue, plus they will last a lot longer.
AGM's are not for everybody, they are sort of a specialized thing and have their own problems and require a different charging profile, if your overcharging LA batteries and put in AGM on the same charger, then your AGM's will die soon.
Do you have a three stage charger and can you set charge voltages?

I assume your batteries are going through water like a thirsty dog?

AGREEED! Big time, ,fix the overcharging issue,bad to breathe, corrosive to everything around it,can you say FIRE! Holy cow man fix that!

[Cadence]

It would appear the me adequate sealing from cabin and venting of you battery compartment would be the fix.

[doublewide]

Not only are your batteries giving off hydrogen - this is normal during charging- they are giving off oxygen. The hydrogen and oxygen come from electrolysis of water. The amount of water loss (and hydrogen and oxygen production) is related to the charging voltage. So don't overcharge them. This means don't use too high a voltage. and don't use an unregulated charger.

In addition to possibly creating an explosive environment (4% hydrogen will do it, and this is not achievable if the compartment is ventilated), you also have the problem of water loss. And if you have AGM or other type of sealed battery, you cannot replace the water. Overcharging will quickly dry out your batteries, and when they are dry they are dead. Check your charge algorithm. Most AGM batteries bulk charge at 14.3V and float at 13.3V.

[mikecambrai]

All wet battery cells must be put into a sealed casing. Hydrogen is very explosive. I now wear a hearing aid after one of my batteries exploded. From the sealed box a pipe must be taken upwards and then over the side.
A box is easily constructed from ply, with the joins sealed.
However you charge wet batteries you will always get gas generated.
In Europe it is part of the regulations to have a sealed vented case.
Please also be aware of sparking which will occur when connecting battery charger clips to terminals and when connecting battery clamps. Always connect the positive first followed by the negative. You should also blow away the area round the top of the battery or fan the area with your hands.
New smart battery chargers can be set for the type of the battery bank. These chargers are a must and not expensive if you look around on eBay.

[CHRIS V CLEMENT]

I have had a Gulfstar 41 for over 10 years. One of my first projects was to add a 4" solar powered stainless steel vents to the center of the forward hatch and the center of the aft hatch. The forward fan has exhaust blades, the aft fan has intake blades. They were originally installed to prevent mildew, but a number of odors, including battery out gassing odors were eliminated. I have since added a CO monitor and have had no issues with my three series 24 wet batteries.

[knockabout]

fit an hydrogen accumulator and use to run your motor

[Isabella Jane]

They only give off gas when boiling. My battery supplier says my silver calcium "deep cycle" wet battery needs to boil briefly at the end of each charge, which it does @ 15 .3 V for a minute or so before dropping to float. Sounds like you are over boiling them. They'll need more topping up if boiling too long. Battery boxes must be ventilated.

[bharney]

Hydrocaps capture the hydrogen gas and convert it to water back to the battery so you rarely need to add water. No fumes in the boat even with heavy charging. hydrocapscorp.com

[conachair]

Originally Posted by doublewide

Overcharging will quickly dry out your batteries, and when they are dry they are dead. .

Charging trojans at 14.8 as recommended by the manufacturers will occasionally set off the very sensitive Co alarm on my boat, but the batteries only require occasional top ups.

From memory the alarm will go off at something like 150ppm. Or 0.015%.

[Akapeterc]

I had the same experience with our CO detectors going off all the time but when I changed to a different battery charger it's stopped. I had a Zantrex and now I have an new enerdrive with a lower setting so it doesn't charge all the time just keeps them on flight mode