ZKETech EBC-A10H blown MOSFET - Help Confirm Part Number - Page 1
Forum section: electronics / repair

author: tifkat
author_rank: Regular Contributor
timestamp: February 07, 2022, 02:00:40 pm
content: I picked up a used ZKETech EBC-A10H battery capacity tester recently, which was from a deceased estate. The seller knew nothing about it, but it powered in and came with all the standard cables.When I set it up and powered it on, it was reading a continual ~8A at 0v with nothing connected.I did some tests and of the two MOSFETs, one had a forward voltage of 2.93v and the other had about 0.05v (testing in diode mode)I dismantled the unit and I found the under-board MOSFET to be in good physical state. It's an IRFP250M. This is the guy with the 2.93v forward voltage.The one with the 0.05v looked a little worse for wear.As it's missing a big chunk, I can't readily identify it. I am assuming that the 2 would be identical, but it would be awesome if someone with one of these testers can confirm the MOSFET which is protruding from the board, next to the temperature component (KSD-01).What else should I check? Would it be sensible to change both MOSFETs together? Should I look at an alternative MOSFET?

author: tifkat
author_rank: Regular Contributor
timestamp: February 07, 2022, 02:34:48 pm
content: Those voltage levels were when testing G to D. Red lead on G, black lead on D.

author: whatboy
author_rank: Regular Contributor
timestamp: February 07, 2022, 03:06:24 pm
content: L9oks like they are in parallel... if so they are equal.

author: sam_sam_sam
author_rank: Contributor
timestamp: May 13, 2024, 10:39:51 am
content: I would like to add something to this post as I have had the same issue with this battery testerThe issue with this battery testing machine is that under no circumstances should you ever try to charge battery packs with any kind of BMS protection boards because some BMS boards do not like to be over voltage or over current and this battery testing machine has the following issues with the way this battery testing machine is designed and setupThe issue is that if the BMS board does not like either situation it spikes the voltage to 24 volts or higher and drops down 0 volts and if you keep trying to charge the battery pack and keep trying it destroys some components on the controller board and I personally have not found the problem with what gets destroyed by this situationWhen you set the voltage and current what you are really doing is setting the current only based on the voltage at the time you start the charging cycle this not an issue when you are charging battery cells that are naked meaning no BMS board of any kind or any other type of device that disconnects the battery from the current or voltageOne other issue that you need to be aware of is if you have a lead acid battery that is not taking a charge is just as bad because it spikes the voltage and there is no current being taken by the battery under being testedThe mosfets are for the discharge mode only and controlled by the controllerThe XL4015 5A DC Buck Step Down Voltage Converter Constant Current ic chip controls the charging system but not in the way this ic chip is normally controlled it is in the current mode only but I have not found any data sheets showing how to use this chip in the current mode only because it is controlled by the controller and there is no information about how this is controlledOne note you can modify this testing machine to only monitor the voltage/current function but you have to remove the mosfets and the XL4015 ic chip and add a jumper wire on the ic chipThe charging relay to the output pin on the XL4015 ic chip footprint and then you can use it as a monitor you also have to add a set of wire to the mosfets board where the are to have this device in parallel with the battery and power supply and the loading of the battery for this to work properlyOne other note you can change the switching power supply from 24 volts to 12 volt switching power to the same footprint also you can us a XL4015 module that has a adjustable voltage/current pots with a voltage meter module boards both of them can be bought from EBay or any other seller that carries them if someone is interested in finding one just post it in this post and I will post a link to where you can find oneWhat I going to build is a BMS protection board system that can test them using the XL4015 module board that I referred to earlier and you manually adjust the voltage and current to suit the battery pack that you want to useI have tested this configuration and concept and does work very good I just not had time to put this together in an enclosure and make it interface with the battery testing machine when I have this project completed I will post some pictures of the completed project

author: sam_sam_sam
author_rank: Contributor
timestamp: September 12, 2024, 10:48:42 am
content: Very important update on this issue about the mosfets going bad on this battery testing machine I have been working on this issue some more recently and have more information about itThe issue with not being able to battery test BMS boards with this device has bothered me ever since it happened to me but I want an answer to the question to WHYyou can not test BMS protection boardsSo a couple of days ago while I was at work I was brainstorming ( not having a brain fart ) about this issue and decided to run this test on my battery testing machine to get some answers how I ran this test is as followsThe the parameters are as followsSet the battery testing machine to CC 4.20 volts @ 1.00 ampsBut here is the twist of this testHook up the voltage leads to a 18650 battery cellHook up the output power leads to two 28 volt incandescent light bulbs in seriesThen hit start on the testing machine what results do you think you will getThe the incandescent light bulbs light up at 24 volts and the screen shows the followingBattery voltage is 3.994 voltsBattery current is 840 milliamperesConclusion is that this battery testing machine only controls the current but to make sure that my hunch is correct I ran the following test several times with different amperage as followsSet to as follows100 milliamperes light bulbs did not light but the amp screen shows 100 milliamperes200 milliamperes light bulbs did not light but the amp screen shows 200 milliamperes500 milliamperes light bulbs are lighting dimly and the amp screen shows 500 milliamperesFinal conclusion is that this battery testing machine only adjusts the current outputBut I have a very important question to ask how is this battery testing machine controller controlling the buck converter circuit I can not find any information about how to control this buck converter in current mode onlyThe data sheet only has how to use it in voltage mode or in cv cc modes together but not only the current modeI did read some where that you use the feedback pin to control the current mode but no one has elaborated about how it functions in detail and better yet with a microcontroller how you would control it

author: sam_sam_sam
author_rank: Contributor
timestamp: May 04, 2025, 11:56:36 pm
content: Here is another major update to the issue about testing BMS balancing protection boards it is POSSIBLE but here is the catch about doing thisFirst you need to modify the battery pack that you want to test with a BMS balancing protection boardThen you have to add testing wires to the battery positive and negative side of all the battery cells to get the voltage output of the battery packThen you take these wires and you hook up these wires to voltage sensing testing wires to the battery testing machine and then you hook up the power test leads to the BMS balancing protection boardThen test battery pack as normal and you will see the current will show nothing when the BMS protection boardI have tested a handful of battery packs with BMS balancing protection board with no issues with the battery testing machineThis has taken a very long time to figure out how to test BMS balancing protection boards with out destroying the battery testing machine doing itI am working on a solution for testing BMS balancing protection boards that are higher than 20 volts because this battery testing machine is limited to 24 volts but when charging 8s1p Lipo 4 battery packs or higher voltages then you have to use another one of there battery testing machines its limitations are that the lowest battery voltage is 10 volts and the maximum is 72 volts but it does not have a charging controller but does have an input that can be monitored by the battery testing machine it will show the charging current and voltage and plot it graph curves just like this one doesI using a switching power supply that has voltage and current adjustable but I have to put it in an enclosure and move the voltage and current meter module I have this setup already but it is not safe to use it this way I just been testing the concept to see how well it works and the results are very promising to the point that I going to be working on the switching power supply enclosureI will post some pictures of the completed switching power supply enclosure and the battery testing machine

author: sam_sam_sam
author_rank: Contributor
timestamp: May 05, 2025, 12:18:21 am
content: Here are some pictures of some results from testing BMS balancing protection boardsI did some research and found out that seem to be a normal way of setting up BMS protection boards with high voltage cutoff for what ever reason but it climbs up very quickly so it does not stay at this voltage for very longI am not sure what the long term effects this has on battery cell life only time will reveal there secrets about the longevity of these battery cellsThese is the biggest reason for me wanting to be able to test BMS balancing protection boards for situations like this