I am currently living in a 12'x12' until I get my Real place up. With the rather compact floor plan I'm at a loss as to where to place my batteries to power my lights, computer etc.
I heat and cook with flame (some lights as well) and I would rather my batteries "not explode". So far my solution was to place my bat in an old cooler, run my inverter cable through a carefully drilled hole and attach said inverter to the top of the cooler. I place the battery outside while running lights etc, connected to the wiring in the cabin by an extension cord.
I was thinking that building a box into the wall that could be sealed via rubber gasket and vented outside. I could still access the battery for changing from inside. I am concerned with cold affecting performance of the battery, but I could insulate the box to some extent. How far from my stove and heater would you think the box should be?
My real home will have a better (and larger) floorplan but for now I'm stuck with this....
We have our batteries under the kitchen counter. We use hydro caps to cut the gassing down. We've only smelled them gassing a couple of times in 4 years. We're using solar panels with an occasional boost from the generator in the winter.
Mine are in the loft in a plastic tote to contain any spills, drips, or condensation. Why upstairs? Warm batteries work much better than cold ones. I use condenser caps, but that's to help keep the electrolyte level up. The only time I noticed off-gassing is when I'd equalize (overcharge) to de-sulphate the plates back when I was charging with a generator. When equalizing, the condenser caps need to come off and the standard caps go back on, and I'd crack a window for ventilation. I equalize much less frequently since I added solar, like once a year.
I haven't noticed any gassing or odors that I can attribute to the battery. My main use is at night. I use one 23w flouresent for light and I run a radio or my laptop to watch a movie before bed. After dinner is done I turn off the light and use oil lamps. A single 550 cca marine battery runs about three days before my low charge on my inverter sounds.
I'm still looking into panels and such, but so far just alternating batteries has worked. I'm not running a typical house or anything.
The attic sounds like a good idea but it's a bit cramped up there due to the pitch of the roof. I think I'll stow them under the sink for now.
Obviously this issue will be tackled in the design of my cabin.
Thanks for the input!
I would use that battery for the boat. Spend the $50 for a 135 aH AGM battery and forever forget about off-gassing.
I bought a "damaged" 130 watt solar panel, a 10amp charge controller and one AGM battery for $250.
As far as your current situation, just keep them well ventilated away from the heat source.
I have 6 golf cart batteries located in a vented bench on the floor of my cabin. I havn't had any problems, but I do only equalise them in the summer with windows open. When I am charging them I'll open the bench up. Cabin has plenty of airflow too, far from airtight. My system isn't perfect, it should be vented outside. And my inverter shouldn't be mounted inside the bench.
I found some good info here http://www.zomeworks.com/tech/H2/H2FAQ.html#4
How much hydrogen does a battery emit?
A charging system that is functioning perfectly will emit only small amounts of hydrogen. For example, specifications from the Johnson Control line of batteries shows that when a floating charge is maintained, 4 - 10 cc/hour/battery of hydrogen is released. When a higher charge is used for equalization, 10 - 20 cc/hour/battery can be expected depending on the size of the battery.
In a shelter that contained 30 of these batteries charging at the higher rate, the hourly accumulation of hydrogen would be 600 cc/hour or .021 cubic feet per hour. At this rate it would take 8 days for a 100 cubic foot shelter to reach the LEL danger zone if the space was sealed airtight. But at this low rate of hydrogen generation, the hydrogen will typically diffuse and leak out without reaching critical levels, as long as the shelter is not truly airtight or has any kind of functional ventilation system.
While a normally charging battery poses little danger, a much more critical situation can occur when the battery charge controller fails to regulate the charging rate properly, and proceeds to "boil off" all the water in the battery. During this kind of failure the rate of hydrogen production can be as high as 3.4 milliliters per minute per Watt supplied by the charger as the water in the battery is converted into Hydrogen and Oxygen by rapid electrolysis. For example, a 1000 Watt charger stuck in "full output mode" can generate 3.4 liters per minute or 7.2 cubic feet per hour. In this example a 100 cubic foot airtight shelter would reach the combustible LEL in about half an hour and would be ready to explode with real force in about an hour or two.
Even though a runaway battery charger may be a rare event, it is not only possible but a likely mode of failure in both conventional and photovoltaic battery charge control systems. When it does happen, it creates a potential for deadly explosion which must be anticipated and disarmed by proper ventilation in the same way that a pressure relief valve is used to disarm the explosive threat of a runaway water heater or boiler. Just like a pressure relief valve, the hydrogen safety vent must be designed to handle the worst case without fail, not just during normal operation, but under any environmental conditions, whenever it occurs.
When does hydrogen burn? When does it explode?
The Lower Explosive Limit (LEL) for hydrogen is commonly accepted to be 4% by volume. For example, the air in a box with a volume of 100 cubic feet that contains 4 cubic feet of hydrogen gas would be expected to ignite when exposed to a spark or open flame. Our own experiments with hydrogen show that such a diluted mixture does not explode, but rather burns off with more of a fizzle than a bang, and so does not represent the severe explosion hazard that one might expect. It isn't until the hydrogen concentration climbs above the 4% LEL to 6 - 8 percent that it pops when it is ignited. When the concentration climbs to 10 - 20 percent the explosive power becomes very impressive, able to blow the doors, roof, or walls off a battery shelter.