I thought mine was a miss after a day and half of swearing with it still just constantly charging.
If anyone else has the same issue just try unplug the ceil from the wall and from the battery, smash the on/off button, reset button a few times and leave unplugged for a few hours then try...
This is a very old thread..... Spent half my day reading it trying to get my new 12v lithium battery working on my old 12v CEIL 850. Long story short, new 100ah lifepo4 takealot battery arrived yesterday morning (sorry Geewiz it was cheaper).. Put it on charge, 24 hours later still...