To extend the battery life, reduce battery usage. You can power off the terminal manually when you are not using it, or wait for the terminal to go into stand-by mode after a set time period. If the handheld will be used in a well-lit area, you may wish to disable the backlight to further reduce battery usage.
It is safe to dock the terminal on the charging base between uses.
Avoid frequent full discharges. Shallow (partial) discharges and frequent short charges are preferred.
Li-ion batteries can hold a charge for many months.