to the amount of electrolyte to use, it must be noted that one cannot
simply give a rule that is generally applicable, since the amount to use
is a function of:
- The number of water compartments (cells); 4, 5, 6 7, or more.
- The spacing between the electrodes
- The desired starting/ending temperature required after a certain
amount of time has elapsed.
- The type of Electrolyte.
- The type and grade of metal.
- The resistance and temperature of the water.
- Environmental Temperature
For a Series Cell with 6 water compartments, you should need
about 1 tablespoon of
NaOH or KOH for every liter of water. Add enough to start with a current
draw of say 10 amps when the water is cold (but no more). As the water heats
up, the current draw will increase. If it gets too hot for you, use less
Here are some figures to use as a guide when operating a 6 series
tube cell configured with 8 inch length tubes, with the smallest tube 1
inch and the largest tube 4 inches in diameter. The configuration will
hold about 1 liter of water without overflowing the upper rim of the
inner tubes and we do not want the amp flow to exceed 16 amps within the
first 2 hours. Add 1/8 cup of NaOH to 1 liter of distilled water (6
teaspoons, or 30 ml of NaOH).
Here is the typical temperature, amp flow and LPM for that
mix concentration....and cell configuration:
- Startup 5 A Cold 0.5 LPM
- 10 min. 7.5 A 0.75 LPM
- 1/2 hr. 10 A 1.0 LPM
- 1 hr. 12 A 104 deg F, 40 C , 1.2 LPM
- 1.5 hrs 15 A 122 deg F, 50 C, 1.5 LPM
- 2 hrs 16 A 136.4 deg F, 58 C, 1.6 LPM
- 3 hrs 17 A 149 deg F, 65 C, 1.7 LPM
- 4 hrs 18 A 163.4 deg F, 73 C, 1.8 LPM
- 5 hrs 18 A 165.2 deg F, 74 C, 1.8 LPM
- 6 hrs 18 A 167 deg F, 75 C, 1.8 LPM
- 7 hrs 18 A 165.2 deg F, 74 C, 1.8 LPM
- 8 hrs 18 A 163.4 deg F, 73 C, 1.8 LPM
As you can see, after 4 hours of continuous operation, the
temperature stabilized at +- 165 degrees F, 74 C, which is ideal!
Note that the temperatures were measured during bench-testing with an
outside temperature of +- 70 F, 21 C. If the cell is installed in a
vehicle with sufficient air flow, the cooling affect of the air flow
could stabilized the cell at a lower maximum temperature. Once the cell
reaches operating temperatures between 140-158 F, 60-70 C, it consumes
about 75 ml of water every hour of operation. So 1 liter of water should
last about 13 hours of driving time. 15 amps does not place too much of
a burden on the car's alternator, thus it should not effect fuel economy
Electrode spacing is another factor that influences the amount of
electrolyte needed to allow a particular amount of amperage draw. In a
series cell, spacing less than 1/16 inch, 1.5 mm, can inhibit the bubble
flow and gas production at higher amps, because the electrolyte starts
foaming and crawling up the tubes. That can reduce surface area
efficiency. In addition, the amount of gas is not related to the amount
of water left in the container; except when no water is left. The amount
of gas produced is determined by the amps. So, you could have peak gas
production right up until the cell runs dry. Whether you have 100 ml of
water left or 900 ml left, that does not determine the amount of gas.
The temperature of the water determines the resistance of the
electrolyte and thus influences the amps that are flowing. So, with less
water in the cell, the temperature is likely to be higher, and more amps
flowing, than with more water. Example, let's say we have only 100 ml of
water left in the cell, with a given amount of NaOH, and the water
temperature is about 158 F, 70 C. We might have 20 amps of current
flowing, resulting in 2 LPM gas production. If we were to add 900 ml of
ice cold water to reduce the temperature to 104 F, 40 C, one might find
that amps suddenly drop to 15 A, and thus have only 1.5 LPM of gas
production. Adding water can actually reduce the gas production. That is
an extreme example but I use it to illustrate that the amount of water
left is not the issue, rather the concentration of the NaOH in the
water. It makes the water more conductive, rather than the temperature
7 Series Cell design:
In order to exceed 100% Faraday calculations, we must go for a 7
series cell (8 plates) if using 13.8 operating volts. The most
restrictive drawback to consider is how long it takes a 7 cells in series to
warm up to a high enough temperature to get decent gas production. When
driving a car, we do not have the luxury of having the cell sitting on a
bench for hours to reach decent gas production. We want good gas
production within a few minutes of driving. Another drawback of the 7
series cell is that it needs 2 times more electrolyte in order to pass
the same amount of current as the 6 series cell above. As we know now, the electrolyte is
indeed slowly being consumed along with the reaction. This makes the 7
series cell more sensitive to electrolyte water mix, so it will have to
be topped up, along with more electrolyte, a lot more frequent. However,
there are advantages. A 7 series cell would be ideal for powering a
generator 24/7, or a commercial diesel truck that seldom shuts down, or
an HHO furnace that operates full time.
A 7 series cell typically needs 7/8 cups of NaOH to produce 4 amps at
startup; 42 teaspoons. Even more frustrating is the slow warm up time.
After an hour, the amp flow will only be around 5 amps, and even after 2
hours, it will only be around 6 amps. We need a decent amount of amps to
generate a decent amount of gas. After 2 hours, this 7 series cell
configuration, will only achieve about 720 mlpm;
compared to the 6 cells 1.6 LPM. That is why 7 series cells are
impractical for a car; plus the fact that that much NaOH concentration
certainly is not very user friendly.
Number of Plates :
References the difference in efficiency comparing cells with 2, 3, 4, 5,
6, and 7 plates in Series. A chart shows the required amperage needed to
produce 1 LPM of HHO -- for each cell plate configuration. It also shows
the plate voltage, and Current Density needed for Continuous operation.
scenarios above are both using straight DC voltage supplied by a
battery/alternator. The cell amperage is controlled by the construction
design, temperature, and by the electrolyte mix. It is possible to
increase the startup amperage. gas production, and control temperature
by pulsing the amperage to the cell. This can be accomplished with a
Pulse Width Modulator (PWM).
The PWM pulses the DC voltage to the cell. Pulsing the voltage turns the
current on off on off on off, thus reducing the heat caused by constant
current flow. In other words, just as the current starts to flow, it
gets stopped. The series of starts and stops happen instantaneously.
The PWM allows you to regulate the amperage (current). This provides
runaway control over the cell. The longer the cell runs on DC, the
hotter the water will get, the higher the amps will go. Eventually you
will blow a fuse, pop a breaker. The PWM solves that problem.
Some PWM's are self regulating; meaning, they are made to operate at a
constant amperage, even as the water gets hotter. You set the maximum
output, and forget it.
Please be advised: A PWM will not increase the capability of your
Hydrogen Generators HHO output. It will do just the opposite. It will
restrict the output; based on what you set it to produce.
During winter months, we need more electrolyte in the water because cold
water does not conduct electricity as well. In summer months, we need
less electrolyte in the water because hot water conducts electricity
much better than cold water. During periods of hot and cold, you are
screwed; unless you have a PWM. The PWM allows you to use more
electrolyte, and control the output of the HHO generator.