Nice work ! I am struggling with 7.5 ego batt so this was nice to get see the guts. Inspired me to pull it apart tonight

Had the same thing came up with a different solution. When that part of the multi fuse is blown instead of soldering you can just connect something between those 2 screw terminals that hold the fuse down bypass it that way. So I added up enough fuses to equal that part (120a) connected them together with wire and terminals, and to those 2 screws. A bit safer solution but either works really.

Thank you sir!

I worked on one of these recently. A transistor had a leg pulled loose. I'm assuming it's from me pulling the silicone up. The trace that connected the leg was pulled off the board and it didn't survive my attempt to resolder.

how bruh i tried and it didn’t work for me

Do u know the pcb name

Just found video love it wanted to do this for my generator ❤

What do you do if the wire one of the five wires is disconnected that go out from there

Same drill, mine charges but only lasts about 5 minutes lol 🤦‍♂️

Wish my LongWei PS-301 was that easy to fix. No short on output and red light off but it wont start up. No voltage/current shown on LED display and green voltage light pulses once every 2 sec and fan tries to start and stops each time. I have 330V DC from mains rectification. Had this prob occasionally from new but now its almost permanent. No sign of physical damaged components.

great video but i think imma get a new battery

950 battery holder

Well done! I’m collecting a library of videos from you guys who are repairing these expensive batteries. Thank you. Winner winner chicken dinner is right!

just had one of mine do the no charge when put in the cradle. Took it apart and removed all the silicone off the board and looked through the magnifier and low and behold, there was a lifted resistor from the factory, soldered it back down and Wala

I just wanted to see what cells were in it. Not accomplished. I'll just take it apart and see for myself. I'd like to upgrade the cells in my old grinder battery. I should just buy a dewalt since I already have batteries to go with my dewalt tools. However I already own an old ht grinder and therfore can't justify buying dewalt grinder just yet. Especially considering I have old cars to keep on the road and bills to pay. Good job rigging your buddy's battery for him. God bless

Clean, flux and tin everything then it will take solder just fine. Also don't heat the solder. Heat the (prepped) work, then feed the solder into the work.

I wish I would have seen this a few weeks ago, I followed a different video and ruined my original install mmc (4800 - not Plus) I'm working with Ugreen to try and fix it but if I can't it will be months before mine gets fixed. Great video.

Jajajajaja Mr. Morrison is the man!!!

Wish your "fix" wasn't out of view..

Could you post a video of the various BIOS menu options?

Everything looked do-able until you introduced that "Smart Charger" @14:00. That just blew up my chances of replicating what you're doing.

These helpless people never picked up a soldiering iron. It’s good to be a jack of all trades at 21! Doing this as we speak haha.

You could be in business forever doing micro minature repair on ego batteries their design alone gives you job security. Think of it a $350.00 dollar battery bought dead on arrival for $20 to $30 dollars, repaired and resold as refurbished for $200.00 as is no warranty gives you a $180 dollar profit. What really bothers me is ego knows their battery quality is so poor they expect you to just trade up and buy a new tool with battery which is cheaper then geeting a new battery. To me this disposable society attitude is so terrible when all ego has to do is sell the perfect product in the first place and stand by it with a lifetime full warranty. No pro rate. One for one swap.

What caused the trace to burn out was improper assembly at the assembly line due to contaminates entering the prodiction line from chineese laborers in a village that that get paid .50 cents a day, no clean room no esd straps no bunny suits, srcond someone touches the mother board with bare hands its doomed to failure. Never mind poor QA.

2 reasons why i see so many ego batteries going bad and red circle of death after first two years and this is gen 4 im talking about, 1) they keep using cheap generic no name 18650 batteries in parallel, and secondly and most important they are designed with subpar discreet wiring of 24 guage or smaller. Ego, listen to me on 56 volt batteries? Really???? The wiring on military aircraft is bigger than that and its onjy 28vdc. Abf has to be light weight. Come on now ego, you can do bettet tgan that l, stop making disposable batteries. Make domething customets can be proud if and btag about in reviews.

Good job pal

Seems like ego BMS’s do not active/passively balance…

I have a 2.5 AH Gen 1 that failed with the flashing green light. Replaced the shorted Q12 transistor and that corrected that issue. I was able to charge and use the battery again. However, within a week, it was now flashing red. Opened it up and this time, only one cell was significantly depleted (0.9V YIKES). Followed this excellent video and charged it up with a power supply to match the rest. Let it sit unplugged from the BMS for 24 hours and that cell held the charge perfectly within 0.01V. Plugged in the BMS, drained the battery with the leaf blower. That cell drained in proportion with the rest of the cells. Charged the pack on the Ego charger, and it charged in proportion with the rest of the cells. So I don't think there was any significant cell damage. Luckily it wasn't depleted too long. So now, if the BMS is unplugged, it holds a charge just fine. but if the BMS is connected, it slowly drains that one cell. (about 0.2 V over a 24 hour period). Any known other failed BMS components that can cause this? Thanks

Man you were making me nervous with your knife around your fingers. I think you were suppose to take the top stop off not the bottom. Which I saw on another video and seems easier. Good info

How is the battery doing after this repair? My 7.5Ah battery stopped charging above two bars (it is a newer model with segmented indicator). I followed this video and found one group was 3.46V and all others at 4.09V after full charge. I charged the "bad" group of 3 cells with 1.5A current to bring it up to 4.09V. I used a programmable DC power supply and did not disassemble the battery, just disconnected the BMS . I am going to test the battery in the same way - to charge / discharge it a few times to see what would happen with the group in question. If the voltage in the trouble group keeps dropping below others I would, most likely, disassemble the whole battery for spare parts. I would not feel comfortable adding three new cells into the old used battery as I would not be able to match them close enough with internal resistance and capacity. Does this make sense? I will post an update here or ask me if I forget to do this. Thank you to the author for sharing the idea.

hey i have a 6.0 AH battery would you like to work on that?

Interesting... make sure your camera is pointed in the right direction dude !! roflmao... don't bother filming !!

200e in Europe 220v

Which cells are in this 21700 or 18650 battery?

I would've just used the balance leads from 4 to 5 and charge from there instead of taking the pack apart. Just set a low current like 0.2A

Do they have silver or gold in them?

Explains a lot and I think it will help me salvage some of mine….. great job

These blow when charging batteries and you get the polarity wrong. Got sick of replacing the diode so I now put the diode across the screw terminals on the outside case connector that way when I get it wrong again and it goes off (sometimes like a cracker) I just unscrew it off and replace it in a few minutes.

I've done this also but found eventually the same low cell bank goes low again and battery goes out of balance again. I think a cell is actually damaged and drops voltage over time. Is this your experience?

hey lmorrison17 is it possible to jump a completely dead 0.0 hyper tough 20v max battery. because i plug it into the charger only one green light is on... when normally charging a batter both indicator lights come on. thnks

Thousands of fires each year from idiots tampering with defective batteries and yeah......great idea to make a video of this and post it on here. No schematics, no idea what all those components are, just tell someone to do this and take chance of burning their home down. Things fail on these boards for a reason.

Good job! Now I’ll know how to replace the zipper pull on my son’s Carhartt jacket. Thanks for the video!

Great job! I’m fixing to have to tear my 5ah apart. Has a green light but won’t charge. Has 49v on it.

Same problem but the Fuse IS good! Now what?

Great video! Nice work!

I was expecting to like flick the bottom, or clean with an alcohol wipe or something. Idk how to do all this!

My solder melted after a few starts. The thing about this fuses it has a copper wire bridge that has a higher specified melting point. I would recommend using silver solder which has a higher melting point. Because this baby does get hot.

TRUE but what the fuc-

True 😳

What did you use to take the white glue/ connector’s coverings off?