I have found the last 5-10% takes ages. Maybe it goes on a 'trickle' charge for the last few %.Depends on battery size (capacity) and the current your charger can put out. Bosch for example do 3 different types of charger, 2, 4 or 6 Amp
with my Bosch 500wh battery and 4A charger it would take about 3-4 hours from flat I would say for a complete charge
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