EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Well I bought another battery testing machine but this one is the EBC-A20 but this one seems to act differently than the EBC-A10H in that when charging it seems to check the voltage every so often or it is not functioning correctly and I have not figured out which case it is but everything else seems to work ok

But I have understand why this one does that every so often and it does not seem to have a certain pattern to it from what I can see so far

In the discharge mode it works just like the other one so I guess I will have to see if it keeps working or not

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I don't think the Mosfets turn on while charging. I think the Mosfets must have some weird configuration, where the large heat sink is on the bottom of the board and the Mosfets mounted to them, cooled by a fan. So I think this section is your "load". The Mosfets should be turned off during charging.
I can't imagine it being any other way. If the Mosfets would be sticking out on top, the N channel Mosets would be facing each other and cooling of them is a headache. So this doesn't make any sense, as it couldn't handle any load at all.
To me the Mosfets are mounted laying upside down to the board (the Mosfets back facing away from the bottom of the board), so a large heat sink can be mounted. So no... those suckers do Jack while charging. The resistors are placed to prevent an accidental turn on of the Mosfets each side. Plus don't forget protection for being hooked up backwards!

Well I have some answers to these questions that you asked about and I was wondering about my self the pictures will tell the story the green wire that you see on left side of the battery testing machine is from the mosfet gate pin and that is where the other meter lead is you will notice where the meter lead is on the battery when on charging and where it is discharging

So it seems that the mosfets are used when charging and discharging this would explain why it would sometimes act up on charging mode and would work on discharging mode and sometimes it would be reversed and it would act the other way but now it does not work correctly in either mode on one controller

Maybe you might have an idea how this is done I am at a loss of how this works

The only thing that I can come up with when it is charging the current is one direction and when it is discharging the current is in other direction because I once had a car that had an analog current meter and in the center was “0” current and to the right of the gauge was charging and to the left side of the gauge was discharging so that might be case that in one it done one way in charging mode and in discharging mode it done a different way this just a guess to what might be going on in this circuit

I might do an forensic autopsy on the controller board but I have not been willing to this yet because I was hoping to get a replacement controller and mosfet board but I have not gotten a response from the company that made this battery testing machine

When I buy another new battery testing machine I will probably do the controller board and I will post some pictures of it when I decide to undertake this when I have some more time

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I will have to try this on one that still works correctly that is not new and see if the mosfets are used while in the charging mode but what I can tell you is that the voltage regulator is not controlling the current this much I can tell you because the on/off sensing pin is not hooked up to the controller board but is at the connector but no wire is in this slot

The regulator seems to be configured for current limiting mode because the resistors and capacitors the configuration that is on this board does not match what is in the data sheet

[CapLeaker]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I don't think the Mosfets turn on while charging. I think the Mosfets must have some weird configuration, where the large heat sink is on the bottom of the board and the Mosfets mounted to them, cooled by a fan. So I think this section is your "load". The Mosfets should be turned off during charging.
I can't imagine it being any other way. If the Mosfets would be sticking out on top, the N channel Mosets would be facing each other and cooling of them is a headache. So this doesn't make any sense, as it couldn't handle any load at all.
To me the Mosfets are mounted laying upside down to the board (the Mosfets back facing away from the bottom of the board), so a large heat sink can be mounted. So no... those suckers do Jack while charging. The resistors are placed to prevent an accidental turn on of the Mosfets each side. Plus don't forget protection for being hooked up backwards!

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Yes one of them works with out the mosfets not installed the volt and current meters work

The other one does not work correctly on the current it will show 5.5 amps or it does not show anything but does not charge any more the voltage meter still works with out the mosfets not installed

[CapLeaker]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

While you’re at it, draw it out. You say the controller board is o.k.?

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

One resistor go from the positive side of the power supply one gate pin to the next resistor then to the next gate pin then to the negative side of the power supply in between the two resistors is the resistor that goes to the controller board which appears to go to one of the lm358 ic chip but I not quite sure exactly where it goes for sure because it has a pin connector on it

(P)———-resistor——— gate pin ———> | <———gate pin ——— resistor——-(N)
><= resistor connection to the controller

I have to check this to make sure I have this information correct I might have this a little bit wrong

[CapLeaker]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

O.k. Somehow the gate pins use three 10k ohm resistors… and where do they go from there?

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

This is the circuit symbol for this mosfets and how it is hookup X2

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Here are the testing results from the battery with a BMS protection board

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Well the strange thing is that they are the same part number for each one

[CapLeaker]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I think the mosfets are placed in such configuration that the body diodes facing each other, preventing current flow either way when off. To make Power go through, something needs to turn on the gate like a management IC or a transistor. I think the Mosfet is one n channel and the other one a p channel configuration? You need to draw a schematic of it, then the picture will be clearer.

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I've been following this thread for a while now. Not sure how to wrap my head around this. Anyway, I think you are stunned a bit having a 10k Ohm resistor on the gate of the Mosfet.

I understand why the resistors are on the gate pins what I have a hard time understanding why you would put a resistor on the positive and negative side of the power supply and have another resistor in series with the controller pin unless you are doing some type voltage divider circuit if so how does it work in the charging mode I understand how it works in the discharge mode

It's common to put such a high value resistor from the gate to GND in order to make sure the Mosfet turns off. It could be that the gate capacitance keeps the Mosfet on (floating), even if it shouldn't (gate drive IC is off). So the resistor bleeds any voltage that resides on the capacitance on the Mosfet's gate pin, guaranteeing the Mosfet to turn off.

I understand this part of this

If I understand your problem correctly, the charger does charge, but for some reason has trouble with regulation?

What I do not understand is how you use the mosfets to control the charging current is what I have a hard time with

Thank you for your response

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Yes but as you put power to the controller it has a short from positive side of the power supply to the negative side of the power side with the mosfets removed the current dose not report anything and if it report anything it does not charge this is the one that does not work at all other than the voltage meter but the current section does not work at all

The other one that does work correctly for the voltage and current it also shorts when the mosfets are installed and I checked the voltage at the gate pin and it is about 6.something volts

[CapLeaker]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I've been following this thread for a while now. Not sure how to wrap my head around this. Anyway, I think you are stunned a bit having a 10k Ohm resistor on the gate of the Mosfet. It's common to put such a high value resistor from the gate to GND in order to make sure the Mosfet turns off. It could be that the gate capacitance keeps the Mosfet on (floating), even if it shouldn't (gate drive IC is off). So the resistor bleeds any voltage that resides on the capacitance on the Mosfet's gate pin, guaranteeing the Mosfet to turn off.

If I understand your problem correctly, the charger does charge, but for some reason has trouble with regulation?

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

The controller that still has a functioning amperage meter and voltage meter and can be used for plotting the data

I did some testing on a battery pack that has a BMS protection board and set the voltage for 4.25 volts and it starts charging at 1.18 amps and drops to 400 milliamperes then adjusted the voltage to 4.45 volts ( external switching power supply ) then the amperage when to 800 milliamperes [ one note the battery voltage is 3.00 to 4.20 volts the battery tester still shuts down the charging cycle when the battery voltage reaches the set point ]

Which is what you would expect to happen when you are not using an [ automatic current controller ] / *voltage sensing still working

I will post the results from this test when it has finished testing the battery pack

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

One controller can not be fixed at this point in time because I am having a hard time understanding how this setup works exactly

Unfortunately I have not gotten a response from the company that makes this battery testing machine

I am going to build a mosfet board with the setup that I descriptive earlier and do some testing to see if I can understand how this works

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Update on this issue with this battery tester

The controller works correctly when it wants to so I have removed both mosfets from the board and going to use an adjustable switching power supply to just charge the batteries with BMS boards like I originally plan to do until I tried to troubleshoot the issue that is wrong with it

The mosfets setup is a little strange to me because I have not seen this before



******In between the two gate pins 10k ohm resistors there is also another 10k ohm then to the controller board

Positive——10k gate—— controller pin ***** 10k ohm *****——gate 10k ohm—— negative
Middle pins go to positive
Current shunt in between the positive and negative sides of mosfets
Outside pins to negative

One interesting thing about the voltage regulator setup it is limited to 5 amps with the resistor the turn on/off function pin is not wired to the controller ( with a motor as a load the output only had 2.5 amps on the input to the regulator was 24 volts @ 3.5 amps for the same motor ) I did not check the voltage that the motor has when going through the regulator

With out the mosfets installed the current is not controlled somehow the mosfets control the current but I have not figured out how they are doing it but my guess is the way the gate pins are configured is my guess but I just do not understand the theory behind this setup on this controller

I understand the discharge mode but not how the charging side of it works with the mosfets

In post #4 I have both side of the board for the mosfets

If someone out there understand how this controller works in the charging mode I would greatly appreciate an explanation of how it is suppose to work ( in this configuration setup )

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

Update from the last post above

It turns out that the controller is not the issue the mosfets interacts with the controller to do the amp calculations I am not sure exactly how but I could not figure out why the controller would not work correctly with out the mosfets not hooked up

So I switch controller boards with the one that sometimes has issues controlling the amperage and it works correctly

The controller that seems to have some issue it might be bad connection to the circuit board which I discovered when switching controllers boards

So I have one mosfets circuit board that is bad which I not going to spend anymore time on because some of the circuit board pads coming off because of trying different things to try to figure out what was the exact issue is

[sam_sam_sam]

Re: EBC-A10H BatteryTesting Machine Mosfet Failure when activate dose not turn off

I know for sure that the controller is malfunction because the new ones do not allow you to start the charging cycle unless you have a battery hookup to the tester and the ones that are having issues it is allowing you to momentarily activate the charging cycle with out the battery hookup up to the tester ( not every time you push the button but if you do it rapidly it sometimes it does it )

One note the one that completely failed it has a short on the battery testing leads when you apply power to the controller board for some reason the the mosfets are being turned on when they are not supposed to be turned on sometimes it will allow you to power on and activate the discharge mode and that portion still worked but it is not always accessible so this is not safe to use it this way