Current Density? Stainless vs Nickel ...

[Roland Jacques]

I'm trying to get a better handle on Current Density.

Since Nickel is 10 times less resistance than 304 SS. Does this mean we can assume that nickel can handle 10 times higher current density? And how does nickel's higher corrosion resistance factor into current density?

Here's a metal conductivity chart
http://www.tibtech.com/conductivity.php

[H2OPWR]

I'm trying to get a better handle on Current Density.

Since Nickel is 10 times less resistance than 304 SS. Does this mean we can assume that nickel can handle 10 times higher current density? And how does nickel's higher corrosion resistance factor into current density?

Here's a metal conductivity chart
http://www.tibtech.com/conductivity.php

From my extensive tests I have found that Nickel cell heats up way slower than stainless cells. That allows more current to be used with out the extra heat. I have found also that media blasting the plate surface for more surface area also helps with more area for the electrons to excape from the plate surface. With media blasted Nickel plates and no holes I have been able to drive the cell much harder than with a non prepared stainless plate cell. I would not say that 10 times is the number. With that said, I do not really know the upper limit of what my cell will take. My power supply will not provide nearly the amount of current that my cell will take. I run up against the limit of my power supply at about 1100 watts. I can only get to about 2.1 volts per plate gap before I start blowing fuses in my variac. With non prepared stainless I can easily get to 2.5 volts per gap. The effeciency starts declining before the power supply runs out of capability. With my Nickel cell I always run out of available amps from my supply before the effeciency starts declining. There is much more to learn.

Larry

[Roland Jacques]

I have wondered how they came up with the "rule of thumb" 1 watt per 4" of plate. (I think thats was it :confused:) And is that rule for 304 0r 316? That chart shows 316L shows to to be more conductive than 304. So Nickel is 7.9 times more conductive than 316L.

So maybe nickel could be 1-2 watts per 1 sq inch.
I am finaly ordering some Nickel to test :).

[Roland Jacques]

Dont forget I have some nickel 200 for sale. :)
Did you end up having any extra 6x8s

[Roland Jacques]

Larry

One of your test you ran 653 Watts into 288 sq inches (textured) = 2.24 watts per inch, at 180f operating temp. So I'm thinking you could have a more manageable Temp, at 1 watt per per square inch. Do you think 1 watt per inche would keep the temp in the 120s?


One stack of 6x6 +nnnnn- with 422 square inches = 30 amps should provide around 2.5- 3LPM enough for any vehicle.

The of cost of nickel is not so bad, if you need 1/4 the amount of plates to produce the same gas. With the added benefit of less maintenance. Electrolyte staying cleaner longer...

[H2OPWR]

Larry

One of your test you ran 653 Watts into 288 sq inches (textured) = 2.24 watts per inch, at 180f operating temp. So I'm thinking you could have a more manageable Temp, at 1 watt per per square inch. Do you think 1 watt per inche would keep the temp in the 120s?


One stack of 6x6 +nnnnn- with 422 square inches = 30 amps should provide around 2.5- 3LPM enough for any vehicle.

The of cost of nickel is not so bad, if you need 1/4 the amount of plates to produce the same gas. With the added benefit of less maintenance. Electrolyte staying cleaner longer...

Yes, With only 1 watt per sq inch the cell never heats up. I was trying to get it to heat up and still did not get where I wanted to ve. My guess would be that at 1 watt per sq inch the cell would never get to 120 degrees.

Larry