Zketech EBC-A40l Battery tester

[@TiborRékasi]

Solder the legs of the transistors on both sides, and RC1-RC8 on both sides, where you reduce the soldering there as well. Also replace the thermal paste with a better quality one. Thermal Grizzly Kryonaut Thermal Conductive Paste 1g - 12.5W/mk I put this. The plate of the blue cover was also very hot for me, I couldn't even turn it off by software during charging, only if I interrupted it or turned it off with the main switch. When I recharged it, the Volts and Amps also dropped during charging, plus the fan didn't start either. I resoldered it, replaced the thermal paste and it works well. My panel is a little different. Worth a try.

[@WiSeNhEiMeR-1369]

HOWdy Dave Rowley, Thanks for the WARNING ! COOP ...

[@snoflite5234]

I bought one off ebay, died during first use. Seller gave me the run around for weeks. Finally got my money back from them. They would not send parts, but needed me to send many video's and pictures. Bought a second off ebay, different seller, bought a extended warantee from 3rd party. Thing has worked perfect. 40amps no issues.

[@johanbraanen2108]

No cables, start burning when connected, half price...are you sure these are orginals?

[@francoisguyot9770]

Sorry for your bad experience. I hope mine won't be that disappointing. I'll make sure to open it and check inside for potential flaws. So thanks for sharing.

[@francoisguyot9770]

@@daverowley9370 I finally tested mine today and I was lucky as I charged my first 280 cell at 40A without any problem whatsoever. The I couldn't get Linux Mint to load the driver for some reasons. But I know that the person who helps Andy from the Offgrid Garage, was able to install it on Zorin. Fortunately I had an old laptop with windows 10 as dual boot and all went OK afterward. I'm actually replacing my Trojan T-875 because they no longer hold a charge. I wonder if your desulfation would work on plain deep cycle sealed acid-lead battteries. How do you use the EBC-A40L to do that by the way?

[@francoisguyot9770]

@@daverowley9370 I watched those videos as well and tried restoring some deep cycle 12V lead acid batteries I found in Home Depot recycling bins. I've not been lucky so far. I only restored one that was totally dried up by adding distilled water and cycling it slowly at 2A. As you mentionned, I could not recover more than half the capacity. Then I tried using an old method that consists of using a large capcitor and a full bridge rectifier. Though it seems to resurect some dead batteries it couldn't restore their capacity in a significant way. People throw them for a reason. At least I got a couple of bucks for properly recycling each of them. That's why I opted for the LiFePO4. Back 4 years ago I was able to get hold of those A123 cells from bus racks. I left them on the shelve for a good 3 years and they had not dropped their nominal voltage of 3.2V. I installed them with an ANT BMS and they have been serving my experimental setup as a 100Ah 48V. They could power my 2 fridges, one freezer and the recirculating pond pump through the night without problem until winter came. So I upgraded the system with 16 280Ah cells and another ANT BMS which I would parallel. It's been working OK albeit with some hick ups which I'm working out. As far as the charger is concerned, it's working strong to top balance my 3d bank of 16 cells in 5 days!!!. But I won't use it to discharge them and find their capacity as it takes way too long and is wasteful. I'll attach a Daly BMS and connect it to my inverter to drain its power down to 3.0V and monitor each cell for any sign of unbalance. Have a great day.

[@AlexanderBartash]

It seems like I have similar issue but it is has not happened yet. I've purchased a unit like that and I wanted to replace a fan to a quieter one. When I opened the case I saw a burned shunt on the left. I've tested a bit how it works and it seems like there are two groups of mosfets and most likely they are supposed to share the load so that each mosfet handles 20A from 40A the unit can handle. What happens is: when I start charging I see that 50% of current flows trough each mosfet but then the current starts dropping quickly on the left mosfet of the right group, which leads to the other mosfet handling 40A and getting hot up to 160C. The shunt before that mosfet is also so hot that even soldering becomes fluid and it is risking to melt the cables below it, there is no protection at all. I've tried to replace thermal compound, did not help. There is definitely an issue. You might be able to fix it by replacing all 4 transistors but you need to make sure that they are from the same production batch because to share the load they must have equal resistance. At least that is what I am going to try. The manufacturer might be using mosfets from different batches and randomly this issue happens for some units. I guess those M-type shunts before transistors have been put into there to balance the current, but in my case they obviously fail to do so.

[@AlexanderBartash]

​@@daverowley9370 Actually just today I seem to have fixed my charger. I even did not have to replace the mosfets. In a nutshell the issue was poor heating. There are 2 groups of mosfets. In each group the one on the left is doing charging and another one on the right is discharging. And since back of the mosfet is conductive they had to put an insulation pad beneath the two mosfets which are responsible for charging and the ones doing discharging are not insulated because they generate more heat, so radiator is conducting current FYI. That is a simple cheap silicone pad which does not conduct heat really well. It turns out when those mosfets heat up they start opening at lower voltages and basically if any of the two mosfets in a group heat more than the other one it starts taking all load to itself because I think it opens more than another one due to overheating, which leads to more overheating. To fix this I've replaced the silicone pads with ceramic pads to improve heat transfer. Also I've bought 2 copper bars 20cm x 4cm x 3mm which are usually used as a ground connection and put one of them below the mosfets so that copper takes heat away and transfers it to the aluminum radiator. Also I've used another copper bar as a press on top of the mosfets, so that it also acts as an additional radiator. For this I've had to remove all mosfets and lengthen their legs because by default they are half way under the PCB. Obviously I've put thermal paste on the ceramic pads, copper bars etc. It would be simpler to replace the whole radiator to copper (it has 2x thermal conductivity compared to aluminum) but I did it this way. Now the mosfets heat up evenly and share the load as they should.

[@AlexanderBartash]

And regarding amperage. I did a few tests and I noticed that disbalance happens even at 20A. But at 20A it is ok because if one of the mosfets is doing all of the work it is ok because if you were charging at 40A and everything worked as designed each mosfet would be handling 20A anyway. So I'd say with these chargers until you fix heating issues do not charge with more than 20A. Discharing 40A is ok because there are no pads under discharging mosfets.

[@tinytv6890]

Exactly the same is observed. Starting charging transistor one and the other after 20A. After 15 seconds on one 37A on the other only 3A. Continued operation in this condition will lead to destruction.

[@AlexanderBartash]

While I was watching multiple videos of people taking these charges apart I noticed that sometimes they come with a very different PCB having different mosfet layout & working principles, so that should be taken into account as well.

[@adnanadnanovice3158]

It gives 40a at 145watt but consumes 311watts??? What's wrong with this thing?

[@dlocke49]

Rut row. I just bought one and am testing it. Manual is totally in Chinese…

[@ericklein5097]

Pretty obvious signs of a knockoff. No clue who the seller is but cheap out on mosfets and they burn because they can’t handle 40A

[@tinytv6890]

I have exactly the same problem - you can see that there are more of us. I will try to replace the transistors with better matched ones. In addition, he plans to choose a different model of the transistor in an insulated housing - he wants to eliminate the silicone spacer. My report in Polish: kzbin.info/www/bejne/o6a2oKtrrp2kmdk

[@daverowley9370]

Yes there is a lot of us. good luck and please tell me if successful. I am not that electronically minded but have a go at most things. There is a local person I may take mine to as my soldering iron is way too hot. Thanks for commenting and hope that Russia stays away from you. Cheers Dave from Australia

[@ivoscuka8537]

Hello, everyone. I have a friend with a broken EBC-A40L, after tests it seems to be specifically with a non-functioning motherboard with a processor-board behind the display. Could someone give me the motherboard from your NON-functioning box? It's a small board, so easy shipping just for a mailing envelope. I would try to replace it for him. I can even pay a little via paypal.

[@rcinfla9017]

I have found them to be pretty poor junk. The ADC that measures the cell voltage is terrible. Only uses a cheap old STM8 Chinese copy clone microcontroller. No where near meeting its voltage or load current accuracy specs. The load current actual on my unit is about 5% off of the display setting.