They replaced the charger that was overcharging, making the dual
lead-acid batteries release hydrogen. So far, the CO sensor is not
registering any H2 with the new charger.
Here's the problem: The guy who installed the new charger said that as
long as there is no H2 registering, keep the charger plugged-in, even
after the green light is lit (full charge). However, the
manufacturer's instructions say: "At green light, keep charging for a
couple of hours for complete charging. When charging finished (Green
LED), disconnect from mains and remove clips from battery. Charging
can continue in 'float stage' without harming the battery."
What does all this mean? Do I disconnect, or not?
It means follow the advice of the guy who installed it. Otherwise you
will need to remember to hook it back up from time to time and I am sure you
will forget the three months prior to needing it. The "Charging can
continue in 'float stage' without harming the battery." Means you can leave
it on without damage. It will use a little power on standby however.
What the hell good is a sump pump battery charger that you have to
plug in and unplug? It's not as if there's never been an automatic
charger invented, either.
Though I don't see the point of a backup battery; it won't have enough
lasting power if you need it (there's a very narrow range of flood
sizes that it will help you with, most being either too small - so
you don't need the pump - or too large - so the pump buys you five
minutes and then the basement floods anyway. It's conceivable that
there's a perfect-sized flood on the way, not too small and not too
large, and you will look like a genius, but I doubt it).
While I tend to agree, they do make sense for anyone with an unreliable
power source and who also needs the pump on a regular bases, especially if
they are on a well, that would not be able to power a jet pump. Power
outages and extra water often go together.
Thanks, Joseph, just one more thing.
The thought of a battery fire or hydrogen saturation is terrifying.
Would it harm the system if I just "topped it off" a couple of hours
per day, every day or every other day, and kept the plug pulled the
rest of the time?
I would think about 30 minutes a week would keep them topped off. It
depends on several factors.
Anytime you charge lead acid you are going to get some hydrogen.
Normally it is not enough to worry about.
A special charger designed to stay on all the time, and just keep the
battery charged, not really charge it, sounds like what you should really be
using. Something in the under 1 amp area.
Dont fret about the hydrogen saturation problem. The buoyancy and
atomic size of hydrogen make it very, very unlikely to cause a
dangerous hydrogen content in your basement. During excessive charging
you will have a small excess of hydrogen gas very near the terminals on
your battery, so be careful about hooking up the charging leads, but
other than there is no worry about the furnace or hot water heater
lighting off hydrogen in the basement. Most trickle chargers operate
at 13.2volts / 1.5amps. The mere milliliters per minute of generated
hydrogen are not a cause to plug and unplug your charger, although if
you are really concerned just put the charger on a timer and forget
about it. Just check your water level from time to time and add a bit
of distilled water if neccessary. AS long as you keep your battery
topped off with water you will not damage it with trickle charging.
Hi, and thanks.
The old charger resulted in a 256 on the CO sensor in the room with
the batteries and 75 on a sensor two rooms away. Someone said you can
estimate H2 by multiplying the CO reading by 2.5. This would be far
below the 40,000 ppm (4% saturation) danger level. Problem is that
the alarm sounds at these low levels and if I disconnect the sensors,
there's no way to know how high the H2 reaches. They're lead-acid
maintenance-free batteries, by the way. Someone suggested they be
replace with gel batteries.
The gelcells are designed to recombine nearly 99% of the hydrogen &
water which may be a good choice in your situation. I am quite
surprised that you are seeing such high CO readings, as I would not
expect that much hydrogen to be evolving. Where again in the CO
detector. I charge a sump pump battery in my basement 24/7 with a CO
detector (digital ppm readout) about 7 feet away around 4 feet off the
ground and never have been above 1 on the readout. You might consider
putting in a different detector to verify the data you are seeing.
Typically the standard home detector is a metal oxide type, which as
far I know is only sensitive to 10 - 15% actual hydrogen content. The
different types of CO detectors are listed below for your reference.
Also I came across a reference that indicated that the maximum rate of
hydrogen evolution of a standard lead acid battery is 0.42 liters per
amp per hour of overcharge. (0.21 liters of oxygen per amp per hour).
Also, contrary to typical representation in MSDS sheets for safety
purposes, the lower flammability limit of hydrogen in air is approx.
4%, while the actual lower explosion limit of hydrogen in air is
approx. 17%. These limits are empirical though and depend greatly on
the the ignition source and other variable. It is always best to be on
the safe side, but this may ease your mind a bit.
Biomimetic (mimics body response) - usually battery operated, but
sensitive temperature and humidity, lasts approximately 6 years. The
technology uses gel-coated discs that darken in the presence of CO,
tripping the alarm.
Oxide Semi-conductor (most common) - usually plugged into wall, uses
Metal more power, sensitive to moisture, lasts approximately 5-7 years.
With this type, heated tin dioxide reacts with carbon monoxide to
determine levels of toxic gas.
Electrochemical (least common, more accurate) - expensive, battery
operated, short sensor life. With this type of sensor, three platinum
electrodes in an electrolyte solution generate energy when they react
Original Charger: The CO sensor was 25 ft. away and plugged into an
outlet one ft. off the ground. The reading was 75 when the alarm
sounded. It is a Kidde Nighthawk CO sensor, direct plug-in. That
same day, the fire dept. got a 256 reading in the battery room, using
a hand-held sensor.
I bought a second Nighthawk, direct plug-in, and placed it 3 ft. from
the batteries, and 5 ft, high.
Second Charger: When the light is orange (charging) the highest
reading in the battery room has been 48. When the light turns green
(charged) the reading drops to zero, which means it could be anywhere
from 0-30 as it doesn't register below 30. The old sensor in the room
25 ft. away is more sensitive, it will show readings 0-30, but they
have so far been zero with the new charger.
I disconnect the charger at night for peace-of-mind purposes and
reconnect the next morning. It takes anywhere from 15 minutes to an
hour for the light to go from orange to green. If I skip a day, it
takes two hours to turn green.
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