why not use 10 cells?

[Torquewrench]

I have been reading this forum for a while, and have found loads of help full information. I am still in the starting stages of tinkering with this.

Why cant we us 10 cells to bring the voltage of a 12v down to 1.2v per cell? Why use seven?

[Bob Boyce]

Hello

Sorry I haven't been on much recently. I have not been feeling well.

I have tried as many as 11 cells on a series 13.8 VDC system. The problem is, as you drop the voltage per cell, the importance of heat energy increases. The following is results of testing series cell boosters of various cell counts on 13.8 VDC.

At 11 cells, the reaction requires a large amount of heat to be pumped into the electrolyte in order to even marginally maintain the reaction. Hydroxy gas production is very low. No actual efficiency measurements were made due to the lack of ability to accurately measure the energy content of required heat input to maintain the reaction.

At 10 cells, the reaction still requires a good amount of heat to maintain it at a fair amount of hydroxy gas output. No actual efficiency measurements were made due to the lack of ability to accurately measure the energy content of required heat input to maintain the reaction.

At 9 cells, the reaction requires a small of additional heat in order to maintain a pretty good level of hydroxy gas production. If heat is not added, hydroxy output falls to a very very low level but efficiency is very high. No actual efficiency measurements were made due to the lack of ability to accurately measure the energy content of required heat input to maintain the reaction.

At 8 cells, the reaction is just above borderline. Enough heat is internally created to maintain the reaction. Hydroxy gas production is good, and efficiency is very high. There is not enough excess heat production to maintain a good reaction if outside temperatures are low enough to draw too much heat away from the electrolyte. This was where I measured the highest efficiency in a self-maintained reaction, 1.52 Watt/hours (W/h) per Liter/Hour (L/h) of hydroxy gas. It can take a very long time for electrolyte temperature to warm up enough to reach maximum hydroxy gas production levels.

At 7 cells, the reaction is enough into exothermic that heat production is a little over the balance between the heat required to maintain the reaction and waste heat production. Hydroxy gas production is very good, and efficiency is still good. There is enough excess heat production to withstand colder outside temperatures, yet not so much that it will cause heat related problems in most types of plastic cell construction. This is where I measured efficiencies of 1.67 W/h per L/h and better. It does take a warmup period for electrolyte temperature to stabilize at maximum hydroxy gas production.

At 6 cells, the reaction produces a lot of waste heat. Hydroxy gas output is high, but efficiency is not so good. At extended run times, waste heat will usually cause meltdown problems in plastic components. Getting rid of heat becomes an issue for extended run times. Measured efficiencies as high as 3.0 W/h per L/h were observed.

When dealing with efficiencies, keep in mind that according to Faraday predictions, it should require 3.34 W/h per L/h of hydroxy gas production. Power consumption below this could be considered above unity by many. I do not share this point of view. I just feel that Faraday did the best he could with what he had available to him at the time.

Please note:
These efficiency tests were made using boosters of my series cell design, which have been designed for high efficiency performance. Similar testing using other designs may or may not produce the same results due to the widely varying inherent efficiency of other designs.

This is not an attempt to convince anyone that my designs are any better than others. Proper design and construction quality/accuracy can go a long ways in making almost any design as efficient or maybe even more efficient than mine.

There is no magic here. This is just good science. Test, measure, and repeat, many times.

Bob

[pertyfly]

So, it would sound to me, that it would be a good idea to possibly try this.

Maybe have 8 or 9 cells in a vehicle or something, with 2 of them having relays (or switches of some sort) on them. Of course they would all be in series, and have it so when cool, only 7 are working. When a certain temp. is reached, the relay turns the next one on to increase efficiency (greatly). If the next specific temp is reached, another is added to the series circuit etc. It would be the same in reverse (due to a temp switch). If the temp drops too low where gas production would be affected, then one is turned off, etc to keep optimum production. At first, for testing it could be done manually, but a temp sensor circuit should work quite well. Of course the heat would easily come from the already created heat from your exhaust/engine harnessed just like a manifold heat riser.

Anyone have any idea on how much heat is needed to sustain 9 or 10 cells? maybe even 11? (Bob?)

That would be a really great experiment since there is so much waste heat anyways, and as it warmed, it would just increase efficiency even more

What do people think of this??

[Bob Boyce]

I have already discussed that next step several times with others in private. For the short term, heating the electrolyte with an immersion heater before pouring it into the cells suffices for testing purposes. Obviously waste engine heat would be the way to go.

My intention is to build a heat exchanger into the bottom of a series cell booster unit, and do testing on how many cells could be maintained at a good reaction and hydroxy gas output with additional heat input coming from engine coolant.

I do have a few concerns about the best design approach. The method to get waste engine heat coupled into the electrolyte, and long term exposure of the plastics to elevated heat.

I want to avoid a circulating electrolyte approach due to the difficulty in limiting bypass currents in a single series cell. In seperate flooded cells wired in series, it would require a seperate heat exchanger for each cell to keep bypass currents from occuring. The best approach may be a compartment below the cell that would allow coolant fluid heat to rise up into the cells.

Through testing with PVC (poly vinyl chloride) and acrylic (plexiglass), these plastics softened even under low grade heat. It will be a design challenge to come up with a low cost housing that can withstand extended exposure to low grade heat and caustic electrolyte. Plate material is not too much of an issue as long as chloride compounds are avoided. Chlorides and heat combine to erode the heck out of stainless steel. Stainless steel in contact with PVC under heat may turn out to be a corrosive combination. Only testing will tell.

Bob

[Dr Dimento]

Sounds like a job for ceramics.....or solid glass. Although admittedly i have no idea what kind of toll electrolyte would take on ceramics....

Anyway, on to my question.... What (from your experience) is the optimum temperature to maintain in an electrolyzer?

[Torquewrench]

So 1.97v per cell uses 1.2v to spit, and the rest goes to bring the temp up to a specific level, any thing over that level is waste heat, and waste heat is waste voltage.

Have I got it right?

So if we use an ouside heat source, like pertyfly was saying, using the right temp then we can use 1.2v per cell?

[Bob Boyce]

[Bob Boyce]