In a normal charging situation, a shift ends and your operator performs his/her end-of-day inspection, parks the lift in its designated area and plugs in for the long haul. "Conventional" charging takes anywhere from 8-10 hours to completely charge the battery. In a perfect situation (and how many of us work in a perfect environment?) that battery would rest for another eight hours. So, conventional charging is really best in a situation where your forklift is used on one shift only.
If you insist on this conventional charging arrangement and operate your unit on multiple shifts, you may want to consider multiple batteries and swapping out those batteries between shifts. This gets complicated and labor-intensive if you have a giant battery.
In the event you're not able to change batteries between shifts,
"Opportunity Charging" involves plugging in whenever you can to keep that battery charged. You'll ideally maintain roughly an 85% charge this way, and then plugging it in at the end of the day to top it off. This eliminates battery-changing, and can actually extend the life of an older battery.
Then there's "Fast Charging." This requires special gear, and can charge a battery three-four times faster than conventional charging. It only charges the battery to about 85% of capacity, and the battery must be fully (100%) charged once a week (weekends?) but this method can increase your driver's productivity by eliminating the battery-change between shifts.
However, fast charging may not be for you. Your charging equipment may require additional power. You may need to Implement more break time into your day (which will make your forklift operator happy but may hurt your bottom line in the long haul.)
Use this criteria to determine if fast charging is for you: If you currently swap out forklift batteries at least once a day, or operate your unit for more than one shift a day- fast charging may benefit you.