I have a Clulite Cluson with 2 batteries (one a spare) which has not been used for a while so in readiness for foxing, I switched it on, but no illumination. I then plugged it in to charge for 24+ hours using the the wall charger. When the wall charger is plugged in and switched on, the lamp illuminates, however, the battery is clearly not holding any charge as when the wall charger is switched off at the plug, the lamp does not illuminate.
I used a 12v Battery charger to charge the spare, again for 24 hours, then put the 'charged' battery into the lamp and switched on. Again, dead as a dodo.
Conclusion: both batteries are deep discharged.
Question: are they recoverable, if so, how?
Thanks in advance for your replies!