So a friend had my second P2V3+ and let it sit over winter, and one batt came back, other is dead.
Can it be recovered?
Normal answer is NO. But why not try?
So I had him give me the dead batt... Yep, nothing. Putting upto 40Vdc into the terminals produced 15ma but nothing; maybe if I left it a day it may have leaked enough in thru the on/off FET to charge enough, but I am too impatient.
So I popped the cover off (search these forum for how to do that), found the MINUS (-) batt input is direct to the 6 cells, and found the + actual batt terminal is big solder blob right above the exposed batt health led #4. If someone is is interested and really wants pix, I can post them.
Sticking my voltmeter directly across the 3 (2 each parallel) cells, showed 1.2Vdc. We all now that if you let a lithium batt go this low it may well never recover. What the heck?
So I put my lab supply to - batt terminal and then other lead to this direct +b terminal... start cranking up the volts... current begins to rise... by 4vdc current would go to 10amps if i let it. Of course I would not. I kept current around 2 amps... watched vdc come up... 4, 6, around here the RED fault led came on! 8, 10, at 10.5vdc or so the fault lite went off and the green first bar came on! I continued for a bit, then disconnected from direct batt cells and let my smart charger take over thru normal 2 batt terminals (after turning it on with 2 button pushes!)... It took off!
When my batt charger started, it was still 10.x volts and rose from there... I like to charge at 2 amps, not 4 like DJI charger, so it is slowly rising... I have it in my 30 gauge ammo box just in case... but I fully suspect tomorrow morning I will come into the shop and see a fully charged battery.
I will fly it this weekend to verify the battery has significant charge left.
Comments?
Can it be recovered?
Normal answer is NO. But why not try?
So I had him give me the dead batt... Yep, nothing. Putting upto 40Vdc into the terminals produced 15ma but nothing; maybe if I left it a day it may have leaked enough in thru the on/off FET to charge enough, but I am too impatient.
So I popped the cover off (search these forum for how to do that), found the MINUS (-) batt input is direct to the 6 cells, and found the + actual batt terminal is big solder blob right above the exposed batt health led #4. If someone is is interested and really wants pix, I can post them.
Sticking my voltmeter directly across the 3 (2 each parallel) cells, showed 1.2Vdc. We all now that if you let a lithium batt go this low it may well never recover. What the heck?
So I put my lab supply to - batt terminal and then other lead to this direct +b terminal... start cranking up the volts... current begins to rise... by 4vdc current would go to 10amps if i let it. Of course I would not. I kept current around 2 amps... watched vdc come up... 4, 6, around here the RED fault led came on! 8, 10, at 10.5vdc or so the fault lite went off and the green first bar came on! I continued for a bit, then disconnected from direct batt cells and let my smart charger take over thru normal 2 batt terminals (after turning it on with 2 button pushes!)... It took off!
When my batt charger started, it was still 10.x volts and rose from there... I like to charge at 2 amps, not 4 like DJI charger, so it is slowly rising... I have it in my 30 gauge ammo box just in case... but I fully suspect tomorrow morning I will come into the shop and see a fully charged battery.
I will fly it this weekend to verify the battery has significant charge left.
Comments?