Dell Latitude 3190 battery failure

[hallb15]

We've got some Dell Latitude 3190 laptops from the DfE that have been in storage for a while. When I've come to test them before giving them out to families in need, some of the batteries are failing (Flashing orange LED when plugged in, dead when not plugged in)

Dell website says 'fatal battery failure.."

 

These batteries are built in, not removable, but I've tried tried disconnecting the battery cable overnight and then reconnecting which didn't make any difference.

 

We don't have the funds to replace these batteries as they are approx £40 each.

 

Does anyone know if there is a way to 'recondition' them back into some kind of life?