Chargery BMS - not detecting current

[Pacer]

Hello-

I recently had to work with Jason at @Chargery to replace my main BMS unit when my previous one failed. Kudos to him for getting me squared away quickly, I am very grateful for his excellent customer service.

Upon replacing the new unit, I have discovered that it is not detecting any current, whether it be charge or discharge. I have reviewed the newest manual closely to investigate, and have attempted to calibrate my shunt to the new unit by following those directions exactly as written, however the BMS is not responding to any of those changes. I’m using a DC power source and setting it for 10A to calibrate, yet the readout from the BMS still reads 0.0A no matter the load or charge to the battery.

Does anyone have any insights or have experienced this issue before? I did send Jason an email asking the same question, but wanted to reach this community as well to explore any possible solutions.

Thank you in advance, and another thanks to Jason for his superb customer service.

 

[Bob B]

Did you have the same problem both before and after attempting to calibrate?

If so, sure sounds like a BMS problem ..... assuming you have everything connected properly ... which seems likely if you kept all your old cable connections and just replaced the BMS.

Curious what the problem was with your other one?

 

[Pacer]

Bob - yes, same problem. When I plugged in the new unit I was not getting any current reading, so I attempted to calibrate.

The BMS is a BMS8T-100A, and to further complicate things I have a 300A shunt from when I first got the package from Craig on this forum last year. I was wondering if that was an issue, but Jason said (in previous emails) that it would only slightly affect the accuracy.

In regards to my first unit, one day randomly I got the magic smoke when I unplugged the power source, nothing out of the ordinary but the poof of smoke. Thankfully Jason was extremely helpful in getting me back up to speed!

 

[Bob B]

Yes ... if using a different shunt, there could be an accuracy problem, but you should still be getting a reading. Have you tried a larger amp draw to see if you get anything?

 

[Steve_S]

I would check the shunt leads with a dvom to make sure you actually have a good wires and connectors first. Also, clean the contact areas on the shunt to make sure there are no oils, waxes or who knows. Not likely that would be a problem but... Then you could use your dvom/dmm cross the shit on the contact screws as well.

 

[Pacer]

Bob - yes, my power supply can produce 10A and it does not register any current.

Steve - the confusing thing is that I hadn’t changed anything except for the main BMS unit, and this had worked perfectly for me previously. I will be investigating to make sure nothing has changed there, but I fear that this may be internal to the main unit. I am unsure on how I could check that, or to check if the sensor is even registering any current at all. Any thoughts?

 

[Bob B]

Bob - yes, my power supply can produce 10A and it does not register any current.

Steve - the confusing thing is that I hadn’t changed anything except for the main BMS unit, and this had worked perfectly for me previously. I will be investigating to make sure nothing has changed there, but I fear that this may be internal to the main unit. I am unsure on how I could check that, or to check if the sensor is even registering any current at all. Any thoughts?

I'm talking about more like at least a 50 amp load.

Have you looked at the connector carefully to make sure it's not damaged ... and that it is fully seated?

 

[Pacer]

I'm talking about more like at least a 50 amp load.

Have you looked at the connector carefully to make sure it's not damaged ... and that it is fully seated?

Bob - yes, I have put a hairdryer load on in which I usually can see up to 60-70A draw when on high, no current registering. I do certainly see the voltage of each cell dip though.

I’m going to really closely investigate the wire and connector, but they both passed my initial check when I first experienced this issue. Still scratching my head!!!!

 

[Bob B]

As Steve suggested, I would check the voltage on the end of that connector with it disconnected from the BMS and see what you get.
If all that looks OK ... better see what Jason has to say about it.

 

[Pacer]

As Steve suggested, I would check the voltage on the end of that connector with it disconnected from the BMS and see what you get.
If all that looks OK ... better see what Jason has to say about it.

Ok so I confirmed that the connector is good by using my power supply and dmm to check that it could read voltage through the cable. I’m thinking somehow this may be related to the sensor within the BMS.

Pinging Jason @Chargery to see if he can guide me on how to check/confirm if that sensor is working correctly.

 

[grizzzman]

How did the first BMS fail? Could it be connected to its failure?

 

[Pacer]

How did the first BMS fail? Could it be connected to its failure?

Grizz- that failure is still puzzling. I was unplugging the external power source to do some maintenance/rearranging of my cells, and upon pulling the plug out I got the pop/magic smoke from the unit. The crazier thing was that I was able to plug that back in, and the unit was seemingly functioning “properly”, however the battery was on the bench at that time so I did not attempt any charge or load for fear of doing further damage. So I really have no idea what went wrong but the smoke was unmistakable so I played it safe and reached out before anything else.

In my email correspondence Jason said that sometimes this has happened, and my old unit should be arriving to him any day now for further investigation.

I’ll take this post once again to reiterate how helpful Jason has been through this process, even sending this new unit out to me the same day I shipped the damaged one back. A+ customer service.

 

[grizzzman]

Did the smoke come out/around the external power port?

 

[Pacer]

Did the smoke come out/around the external power port?

Not that I could tell, it seemed to be further in the unit.

 

[Pacer]

Update today - I had disconnected everything last night, and came back fresh this morning. Plugged the unit in, confirmed my PS was good to go, and recalibrated the BMS.

Great news, I’m back in business! I honestly can’t say what the difference was, but somewhere along the line I will attribute something to operator error. I’m just glad to have a functioning system again, thank you all for the insight and support.

 

[Raulito4738]

Hello, I just received two Charger BMS24T and it does not detect voltage, if it detects the number of cells in series but no voltage

 

[Bob B]

Well ... that says BMS16T ... not 24T.

Did you disconnect the balance lead plugs and verify the voltage readings with a meter?

If you have 2 with the same symptom it is likely mis-wired.

 

[Raulito4738]

Si lo he verificado varias veces estoy probando un bms16t y si reconoce el voltaje aquí te mando una foto

 

[grizzzman]

Well ... that says BMS16T ... not 24T.

Did you disconnect the balance lead plugs and verify the voltage readings with a meter?

If you have 2 with the same symptom it is likely mis-wired.

zoom in on the screens and it says 24S also lipo

 

[Bob B]

zoom in on the screens and it says 24S also lipo

The picture clearly shows the model as BMS16T ..... I guess I should have just ignored this since I don't know anything about the 16T ... or how it can be configured for 24S

Si lo he verificado varias veces estoy probando un bms16t y si reconoce el voltaje aquí te mando una foto

So .... that shot shows voltage readings .... did you resolve it?