You can use anything that will supply no more than 4.2 V. Ideally, you will be able to regulate the current but it’s not 100% necessary. Any little DC DC converter off of eBay or Amazon will do. send it to the voltage. All your other cells are resting at and bring the group up slowly.
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.
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.
I had 19 ego batteries. 6 of the older type, 13 of the fuel cell type. All 13 newer were out of balance & bringing them back to balanced made the batteries work again. They all still work but they are going out of balance still...... Slowly, but surely. All new cells is the only way to repair these properly. I used molicel. They are not simple though, especially over 2.5ah.
The pin holes in the connector are smaller than regular header pins. I will often use bread board jumper wires but they didn’t fit. I suppose I could have used a sewing needles in the holes but they awfully close together, good chance of an accidental short with my shakey hands.
Explains a lot and I think it will help me salvage some of mine….. great job
Great video! Nice work!
Everything looked do-able until you introduced that "Smart Charger" @14:00. That just blew up my chances of replicating what you're doing.
You can use anything that will supply no more than 4.2 V. Ideally, you will be able to regulate the current but it’s not 100% necessary. Any little DC DC converter off of eBay or Amazon will do. send it to the voltage. All your other cells are resting at and bring the group up slowly.
Nice. Very helpful.
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.
Jajajajaja Mr. Morrison is the man!!!
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.
I had 19 ego batteries. 6 of the older type, 13 of the fuel cell type. All 13 newer were out of balance & bringing them back to balanced made the batteries work again. They all still work but they are going out of balance still...... Slowly, but surely. All new cells is the only way to repair these properly. I used molicel. They are not simple though, especially over 2.5ah.
Seems like ego BMS’s do not active/passively balance…
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
The pin holes in the connector are smaller than regular header pins. I will often use bread board jumper wires but they didn’t fit. I suppose I could have used a sewing needles in the holes but they awfully close together, good chance of an accidental short with my shakey hands.
Which cells are in this 21700 or 18650 battery?
18650
Do they have silver or gold in them?
No