Hi
Have you seen this video on open ppg battery repair. How many had this issue about bad welding from factory?
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I havent seen bad solders from factory on any of the batteries I’ve repaired.
Ive had to do probably a dozen connector replacements for burned resistor, on the older QS8 connectors.
And two BMS replacements.
I have a name for being the “electric paramotor” guy in my area and have offered to help many other SP140 owners.
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Hey Dennis, I have a similar problem as the video described with one bad series that is significantly lower than the rest. Would you be open to fixing this for me? I’d pay
Hi, Where are you located? Shipping a battery is often pretty expensive especially long distances.
Also, how old is you battery? What is low cell group at when the others are charged? As in what is the spread?
If it’s a matter of manually balancing that group of cells I can do it, yes. But if the cells test bad and need replaced, I don’t think I can help you with that.
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I am in Montana. Last time I shipped via USPS and it was around $100 with insurance when I used PirateShip.com. Where are you?
The battery is from Febuary 2023 but has never been flown and only has 1 charge cycle on it according to the BMS. I have attached two screenshots showing all the charges on the strings and the Delta v
Is there a way to send direct messages so we can continue to talk details? Sorry I am new here and still figuring it out
You better charge up group 6 quite fast, otherwise it can soon go below 3V and after that it will self discharge even faster! If you are somewhat handy, you can do it yourself quite easy. You just need a rc charger or adjustable power supply that can do 4,2V.
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Ok thanks for your help. A few questions-
-so for materials, I need a multimeter to identify the bad group, a bench supply to charge the bad group, and more insulation tape? Anything else? What is the name of the insulation tape I should look for?
Once the battery is open, is it easy to identify the individual strings with the multimeter?
What charging parameters should I use to charge the bad string up? To what voltage?
If I need to replace individual cells, what should I look for with the multimeter to identify them? How would I remove them? Just break them off the cells on the welds and re-weld the new cells?
Thanks again
So what you will need is a multimeter to find the group. For this you need to open up the top case, remove the first ribbon cable, one with the black wire and measure each two wires starting from the black one. Black to first red should read 4,1V and fifth and sixth red wire should give you 3,3V.
This is where you connect your power supply or R/C charger. And you will need to charge to same voltage as the rest of the cells so around 4,17V but its ok to charge it fully to 4,2V. Use no more than 3-5A to do so as BMS connector dont really like to handle more than that.
You dont need to have any specific tape for this just mind the connections(charger to ribbon cable) as you can easily short something if you have som bare wire exposed, so pay extra attention.
Now to change the cells is a lot more work so lets take it later when you do your first step.
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Thank you for the advice, I have ordered the materials and will hopefully attempt it soon
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