Hi All
Thought I might share this snippet for anyone interested, My P3P RC battery failed, at first I thought it was discharged due to leaving it on.. ? anyway it would not accept charge, so I opened up the RC to investigate.
I measured the battey voltage with an AVO, nothing 0 Volts, so I went further, stripped away the outer protective PVC film to expose the small circuit board within the battery casing, measured the voltage at the PCB terminals, Cell 1 = 3.74 volts, Cell 2 = 0V, on closer inspection I found the problem.
Without trying to go into too much detail, the outer shell of the LiPo cell is formed from a foil coated with a conductive resin ( Look on line you will find a better description ). The connection to the circuit board is achieved by bonding a thin strip of this coated foil to a nickel tab which is then solderd to the PCB terminal.
This thin strip is the week point, it had slowly corroded away so that it was no longer attached to the nickel tab.
Having carefully cut away the blue outer PVC sheath and peeling back a strip of the Grey inner protective sheath I exposed the conductive surface of the LiPo cell, now when I measured the voltage between the Common 0v connection and the surface of the cell I got 7.6 volts.
So the only problem with the battery was the foil strip had corroded away, now obviously you cannot solder a new connection to the foil so what I did was to make a small copper foil pad to which I soldered a thin wire, then I applied some Silver Conductive Epoxy glue to the pad ( link to glue info https://www.techsil.co.uk/media/pdf/TDS/MGEP00005-tds.pdf) and stuck the pad to the conductive surface of the Cell.
When it had cured I covered the repair with some gorilla epoxy glue and stuck back the Gray outer sheath that I had cut back to expose the conductive surface, and waited for that to cure.
Job done ( nearly ) I soldered the wire to the PCB connection pad, checked the voltage at the connector, plugged it into the RC, and it works perfectly.
Finally I covered the repair with Duct tape, now the jobs done
If you want more info post your question.
PS I would not do this repair to a Flight battery, way to much current drawn, but for an RC it's OK
Here are some photo's
Thought I might share this snippet for anyone interested, My P3P RC battery failed, at first I thought it was discharged due to leaving it on.. ? anyway it would not accept charge, so I opened up the RC to investigate.
I measured the battey voltage with an AVO, nothing 0 Volts, so I went further, stripped away the outer protective PVC film to expose the small circuit board within the battery casing, measured the voltage at the PCB terminals, Cell 1 = 3.74 volts, Cell 2 = 0V, on closer inspection I found the problem.
Without trying to go into too much detail, the outer shell of the LiPo cell is formed from a foil coated with a conductive resin ( Look on line you will find a better description ). The connection to the circuit board is achieved by bonding a thin strip of this coated foil to a nickel tab which is then solderd to the PCB terminal.
This thin strip is the week point, it had slowly corroded away so that it was no longer attached to the nickel tab.
Having carefully cut away the blue outer PVC sheath and peeling back a strip of the Grey inner protective sheath I exposed the conductive surface of the LiPo cell, now when I measured the voltage between the Common 0v connection and the surface of the cell I got 7.6 volts.
So the only problem with the battery was the foil strip had corroded away, now obviously you cannot solder a new connection to the foil so what I did was to make a small copper foil pad to which I soldered a thin wire, then I applied some Silver Conductive Epoxy glue to the pad ( link to glue info https://www.techsil.co.uk/media/pdf/TDS/MGEP00005-tds.pdf) and stuck the pad to the conductive surface of the Cell.
When it had cured I covered the repair with some gorilla epoxy glue and stuck back the Gray outer sheath that I had cut back to expose the conductive surface, and waited for that to cure.
Job done ( nearly ) I soldered the wire to the PCB connection pad, checked the voltage at the connector, plugged it into the RC, and it works perfectly.
Finally I covered the repair with Duct tape, now the jobs done
If you want more info post your question.
PS I would not do this repair to a Flight battery, way to much current drawn, but for an RC it's OK
Here are some photo's