How to get charging started for deep discharged batteries

[will.moindrot]

Hi,

typical story - phantom 4 packed away for house move, prior to this charged batteries, didn't check batteries during that time. Finding now that 2 of my 3 are not charging, no lights coming on during charge. The third was on one flashing light, and plugging it into the charger it has begun charging and gave full capacity. But even leaving 1 and 2 plugged in for 4/5 hours nothing.

I have seen a few posts of people with similar but no real responses apart from one to do with disconnecting a balancer lead in the battery momentarily. Has anybody tried this/ know any more?

I'm pleased I have one, but I'd like two better!

Thanks, Will

 

[N017RW]

It could be too low voltage for the charger to recognize it is there/connected sort-of-speak.

It would require a direct connection to boost voltage up to a level normal charging would then occur.

Not an easy operation and risky.

 

[Just_nick]

Those two batteries that do not light up are dead, assuming you don't have a LiPo charger and are willing to do some battery dissecting.

 

[will.moindrot]

I don't have a LiPo charger unfortunately, would this be just one for RC cars etc.? any specific requirements? I would be happy to do some dissecting to bring these back into service although I know it's not a given that they would then work. I saw a post by one P4 guy out there who found that even with the charger now working on it (having done charging via a dumb charger) it failed to deliver power to the phantom. Happy to give it a go to continue to get some return on the £160 paperweights!

Update: Sod that - least I know where I am with one battery! This video did it for me: