My build (very slowly progressing)
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@czahl ah I think @danielfp248 would know this answer, he has flashed most of the firmware but I don't remember him saying he made any changes. He is traveling right now so it may take him a bit to get back to us. I have only used the MYSTAT, I haven't dealt with the firmware myself. If he made any changes then we can push them to the repo ASAP.
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@czahl We have never updated the firmware, we use the same one as the original mystat paper. Errors when saving calibration are often related with the calibration parameters being of the incorrect numerical type or the values being too large. There might be a bug in the UI around this. I'll check when I'm back from my traveling, however I dont remember having issues saving these values when calibrating successfully with the 1k ohm resistors.
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@czahl We have never updated the firmware, we use the same one as the original mystat paper. Errors when saving calibration are often related with the calibration parameters being of the incorrect numerical type or the values being too large. There might be a bug in the UI around this. I'll check when I'm back from my traveling, however I dont remember having issues saving these values when calibrating successfully with the 1k ohm resistors.
@danielfp248 said in My build (very slowly progressing):
We have never updated the firmware, we use the same one as the original mystat paper
Are we talking about the same mystat repo? Again in my understanding this paper reflects the PCB from PcbWay, und this has the 4 reed relais (on top of the picture) for the 4 current ranges. In the main.c only the original 3 are handled.
Somewhere there is a mismatch, or am I'm looking into the wrong repo?
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@danielfp248 said in My build (very slowly progressing):
We have never updated the firmware, we use the same one as the original mystat paper
Are we talking about the same mystat repo? Again in my understanding this paper reflects the PCB from PcbWay, und this has the 4 reed relais (on top of the picture) for the 4 current ranges. In the main.c only the original 3 are handled.
Somewhere there is a mismatch, or am I'm looking into the wrong repo?
@czahl I dont know which files kirk used to create that repo. I use the firmware directly from the repo linked on the mystat paper.
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@czahl I dont know which files kirk used to create that repo. I use the firmware directly from the repo linked on the mystat paper.
@danielfp248 Thanks for the hint this is the reason. In the version referenced in the paper, the firmware is extended to support the 4 current ranges.
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@czahl We have never updated the firmware, we use the same one as the original mystat paper. Errors when saving calibration are often related with the calibration parameters being of the incorrect numerical type or the values being too large. There might be a bug in the UI around this. I'll check when I'm back from my traveling, however I dont remember having issues saving these values when calibrating successfully with the 1k ohm resistors.
@danielfp248 said in My build (very slowly progressing):
however I dont remember having issues saving these values when calibrating successfully with the 1k ohm resistors.
I need to actually do the real calibration when I find the time. I'l report back then.
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@danielfp248 I managed to get the mystat working correctly and calibrate it too. The problem was the firmware. I was using the one from @kirk's repo but that's the one working for only 3 current ranges. https://github.com/matthew-yates/MYSTAT/blob/main/firmware/firmware.hex is the correct one to use with the updated board. Should I create a pull request?
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@danielfp248 I managed to get the mystat working correctly and calibrate it too. The problem was the firmware. I was using the one from @kirk's repo but that's the one working for only 3 current ranges. https://github.com/matthew-yates/MYSTAT/blob/main/firmware/firmware.hex is the correct one to use with the updated board. Should I create a pull request?
@sepi yes, please do.
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After my flasks have arrived, I was finally able to mix the electrolyte tonight. I'm a bit surprised by the "recipe" producing only short of 10ml. Is this enough or is it meant to be scaled up for usage in the battery?
I was also wondering how to properly do this in a non-lab setting. How do you clean your glassware before and after use? Can I use regular tap water and clean with paper towels?
I collected the waste water used for cleaning (the first rinse) in a PP bottle. Should I give it to the special waste facility that also handle old batteries and paint for disposal? Do they need to know what it is?
Also, how precise do I need to be? I got a new precision scale and tried being accurate to the third digit but I wonder how important this really is.
Can I just pour water over the mixed salts or should I do it the other way around. I have this vague idea that the first way might be dangerous, or is this only with acids?
Anyways, I bow have a tiny amount of slightly yellowish liquid eagerly waiting to be put to use. Do I need to store it in special conditions except for a closed vial? Does it degrade quickly? Also how badly do the reagents themselves degrade? IIRC, the zinc chloride was extremely hydrophillic (I guess it's not the hydrated form), is it fine to leave the container open for a minute or two?
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After my flasks have arrived, I was finally able to mix the electrolyte tonight. I'm a bit surprised by the "recipe" producing only short of 10ml. Is this enough or is it meant to be scaled up for usage in the battery?
I was also wondering how to properly do this in a non-lab setting. How do you clean your glassware before and after use? Can I use regular tap water and clean with paper towels?
I collected the waste water used for cleaning (the first rinse) in a PP bottle. Should I give it to the special waste facility that also handle old batteries and paint for disposal? Do they need to know what it is?
Also, how precise do I need to be? I got a new precision scale and tried being accurate to the third digit but I wonder how important this really is.
Can I just pour water over the mixed salts or should I do it the other way around. I have this vague idea that the first way might be dangerous, or is this only with acids?
Anyways, I bow have a tiny amount of slightly yellowish liquid eagerly waiting to be put to use. Do I need to store it in special conditions except for a closed vial? Does it degrade quickly? Also how badly do the reagents themselves degrade? IIRC, the zinc chloride was extremely hydrophillic (I guess it's not the hydrated form), is it fine to leave the container open for a minute or two?
Congratulations on getting all the chemicals needed!
@sepi Let me answer your questions:
After my flasks have arrived, I was finally able to mix the electrolyte tonight. I'm a bit surprised by the "recipe" producing only short of 10ml. Is this enough or is it meant to be scaled up for usage in the battery?
When we run battery experiments we generally only run 5mL per side, 5mL on the catholyte side and 5mL of the anolyte side.
I was also wondering how to properly do this in a non-lab setting. How do you clean your glassware before and after use? Can I use regular tap water and clean with paper towels?
Clean with tap water, then clean with alcohol or acetone, then clean with a paper towel.
I collected the waste water used for cleaning (the first rinse) in a PP bottle. Should I give it to the special waste facility that also handle old batteries and paint for disposal? Do they need to know what it is?
This depends on your local regulations, you should contact your local authorities to see what they require. You can precipitate everything in the solution by adding Cu carbonate (mainly potassium chloride would be left in solution), the insoluble solids can then be disposed of more easily. Storing solids is also easier as they occupy less space.
Also, how precise do I need to be? I got a new precision scale and tried being accurate to the third digit but I wonder how important this really is.
Preparing the salts to +/-0.1g should be precise enough.
Can I just pour water over the mixed salts or should I do it the other way around. I have this vague idea that the first way might be dangerous, or is this only with acids?
For these amounts this is fine, for larger amounts (10x this), adding the salts to water would be more desirable.
Anyways, I bow have a tiny amount of slightly yellowish liquid eagerly waiting to be put to use. Do I need to store it in special conditions except for a closed vial? Does it degrade quickly? Also how badly do the reagents themselves degrade? IIRC, the zinc chloride was extremely hydrophillic (I guess it's not the hydrated form), is it fine to leave the container open for a minute or two?
It needs to be stored in an airtight container as the iodide in solution will react with atmospheric oxygen, it will turn yellower and then red as this happens. You can put a strip of metallic zinc inside the solution to better preserve it. About the ZnCl2, it is very hygroscopic, so you should open this container for as short of a time as possible. I try to weigh it in less than 20 seconds to introduce as little water as possible from the air.
Please remember to wear proper PPE when doing all of these experiments and make sure you do so in a place that's well ventilated.
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@danielfp248 Thanks for the quick and thorough answers! You should add those points to the docs unless you feel that this might potentially create legal trouble.
About the PPE, I was wearing nitrile gloves, cotton work cloths and plastic safety glasses (not closed though). I felt reasonably safe
About the copper carbonate for precipitation, would that be the natural one or basic one? Since I'm curious and want to bring my chemistry skills up to date: how do you know that this will cause precipitation? Is this compound used frequently for precipitation? Is this about chemical potential of copper iodide (s) and zinc carbonate (s) being lower than the sum of their respective ions (aq) in solution?
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@danielfp248 Thanks for the quick and thorough answers! You should add those points to the docs unless you feel that this might potentially create legal trouble.
About the PPE, I was wearing nitrile gloves, cotton work cloths and plastic safety glasses (not closed though). I felt reasonably safe
About the copper carbonate for precipitation, would that be the natural one or basic one? Since I'm curious and want to bring my chemistry skills up to date: how do you know that this will cause precipitation? Is this compound used frequently for precipitation? Is this about chemical potential of copper iodide (s) and zinc carbonate (s) being lower than the sum of their respective ions (aq) in solution?
@danielfp248 Thanks for the quick and thorough answers! You should add those points to the docs unless you feel that this might potentially create legal trouble.
I think we can add these as reasonable guidelines, we will include clarification that waste disposal should always be consulted with local regulations though.
About the PPE, I was wearing nitrile gloves, cotton work cloths and plastic safety glasses (not closed though). I felt reasonably safe
That seems adequate, especially if adequate ventilation is also in place. The quantities are small, so hopefully this also reduces the risk.
About the copper carbonate for precipitation, would that be the natural one or basic one? Since I'm curious and want to bring my chemistry skills up to date: how do you know that this will cause precipitation? Is this compound used frequently for precipitation? Is this about chemical potential of copper iodide (s) and zinc carbonate (s) being lower than the sum of their respective ions (aq) in solution?
This is because Zn carbonate and Cu iodide are insoluble so a double displacement reaction occurs and both fall out of solution. There is an additional complication in that Cu+2 does oxidize I- to elemental I2, so you will also have some solid iodine formation. What precipitates is actually Cu(I) iodide. You can add some Na thiosulfate if you want to make sure all iodine precipitates as copper (I) iodide.
