Bumping an old thread here I think, but reading through it there is some really good information and tips.
The reason I'm posting is that I recently bought an MP1 with 3 batteries, these all seem to be charging ok, for now anyway.
I also just bought a fly more pack, it was brand new, I'm assuming to the seller, everything still in wrappers, apart from the 2 batteries.
These I put on the charge cube and got nothing but the red led of doom.
Pressing the button on the battery did nothing.
So after doing a bit of research, I then plugged in the charger lead direct into the battery and left them for 12hrs on charge, thought maybe deep hibernation mode.
Still nothing, pressing the on button got no response.
So I dug a bit deeper and done some more reading and video watching, mainly people busting battery cases to get the things apart.
What I noticed was that the 2 main power cables from the battery board ran up inside the front cover of the case.
So I drilled a small hole in each corner where the case curved and sure enough, there was the red and black cables.
So using a multi-meter, I probed the cables and found a low voltage was there which told me that they connected to the battery cells.
So using 2 sewing needles as connectors I used the output on my balance charger to supply power to these cables.
Charger set to 3s at 0.5A and left it to slowly build up to 11.4v, took about 90 minutes.
I then re-checked using the meter and found, 11.38v.
I then pressed the on button and the battery scrolled the led's and sat at 3, so I plugged it into the DJi charger and it scrolled the led's again with 3 solid lit and No.4 blinking
I repeated the above with the second battery and got the same results.
However....after 12hrs of being on charge, the led's on both have dropped to 2 solid and 3rd one blinking.
Putting the battery on the drone does nothing.
I can switch the batteries on and off with the power button, but don't appear to be taking a charge from the DJi power supply and putting them on the 4 way, after some green blinking led, it goes solid red.
What I am thinking is that either the cells are out of balance so the internal board won't let it charge...or that the chipset has the perm fail fault flag.
So, I'm going to open the cases up and do the balance charge lead mod from the OP of this thread, and while I have it in bit I'm also going to plug into the BMS chipset and see if there are any fault flags and erase them.
I'll post back here as and when I make any progress with what I find, it might be a while as shipping is a bit slow for stuff to arrive etc.
Oh and Hi from a new member..