green/orange flash indicates your battery is too hot to charge

I have Latitude D820.

The battery indicator (in the device status lights area on my laptop) started flashing green and orange. Dell manual says it happens when battery is too hot to start charging. 

1. Although battery wasn't hot at all, I disconnected laptop from electrical outlet, removed battery for one day and then put it back - it didn't work, the indicator still flashing.

2.When I remove the battery and turn it on, the indicator stops flashing.

Any idea?

Thank you.

Flashing red only means a dead  battery.

Flashing alternate green and amber means one or more cells in the battery is faulty - it's an early warning you'll soon need a replacement battery.