Monitoring current from a charger with a ZRA

Hello, everybody! Sorry if I have posted this in the wrong forum, but this one seemed appropriate. I want to hear your ideas about a setup I will build. I want to register the current a charger is providing to a battery during the charging period.

The charger uses CCCV charging (constant current up to 4,2V, then constant voltage until the current is ~5% of the original current).

I will use a potentiostat connected as a ZRA (zero resistance ammeter) to monitor the current. You can read the instructions on how to connect it if you want here, "Special Case Setup: ZRA Mode" at the bottom of the page.

You can see my setup here

WE = Working electrode
WS = Working sense
CE = Counter electrode
CS = Counter Sense
Ref = Reference electrode

I will then program the potentiostat to keep a 0 net voltage drop between WE and CE.

What are your thoughts here: will this setup work in monitoring the current during charge?

Why?

What is wrong with doing what the rest of the world would do and use a conventional ammeter of some kind?

Will the "Potentiostat" measure the current which you are likely to get from the charger?

This seems to be a case of making a simple problem very complicated. Or am I missing something here?

JimB

JimB said:

Why?

What is wrong with doing what the rest of the world would do and use a conventional ammeter of some kind?

Will the "Potentiostat" measure the current which you are likely to get from the charger?

This seems to be a case of making a simple problem very complicated. Or am I missing something here?

JimB

Click to expand...

The potentiostat is the only equipment I have access to that can log the current and time automatically.

Yes, the potentiostat will measure and log the current as it varies through the whole charge process, for approximately three hours.

OK but what is the maximum current that the Potentiostat can measure, just reading the application note in your link it seems to be a very low current device.

Is it rated to measure the expected charging current?

JimB

It is a pretty advanced potentiostat actually, it can be set to different ranges. The current is expected to be between 20 mA and 0,2mA. The potentiostat can handle currents atleast down to one microamp. As long as the setup is right it shouldnt be a problem. Are you familiar with zra setups?

Are you familiar with zra setups?

Click to expand...

No I am not.
I had never heared of a potentiostat before I read your initial post.

The concept of a ZRA piqued my interest.

Just reading the Gamrie application notes for the potentiostat, it looks as though it would work.
I would however defer to anyone with real knowledge of the potentiostat.

If you end up with a smoking hole in the bench top, dont blame me!

JimB

JimB said:

No I am not.
I had never heared of a potentiostat before I read your initial post.

The concept of a ZRA piqued my interest.

Just reading the Gamrie application notes for the potentiostat, it looks as though it would work.
I would however defer to anyone with real knowledge of the potentiostat.

If you end up with a smoking hole in the bench top, dont blame me!

JimB

Click to expand...

Well, it didn't work. Now I'm off to Scotland with a chainsaw, where you at?

I am logging the current manually instead with a simple old multimeter instead, sigh...I am confused why it didn't work. I will post in this thread if I find a solution.

I am logging the current manually instead with a simple old multimeter instead

Click to expand...

Sounds familiar, didn't someone suggest that earlier?

JimB

JimB said:

Sounds familiar, didn't someone suggest that earlier?

JimB

Click to expand...

It is with disgust I am admitting this defeat, logging valuesmanually each 30 sec for probably 1 hour.

I probably would have put your Ref terminal at the red line or common at the bottom of your picture.

Anyway, i have seen a potentiostat, although a very old one and our lab got a new one, but I knew little about it.

I did read some info on corrosion monitoring and I know the currents are much higher.

I have built ZRA's or as I prefer to call it, a 4-terminal ammeter with bias but for a different purpose.

My comments would be:
1) Ammeter range
2) How might you measure the battery voltage, That should be important too. It's possible that by moving ref to the bottom of your diagram, you might be able to measure both current and battery voltage PROVIDING the voltage and current ranges of the instrument are compatible with the setup.