Don't forget safety first.
Don't add new electrolyte (acid).
Don't use unregulated high output battery chargers to charge batteries.
Don't place your equipment and toys into storage without some type of device to keep the battery charged.
Don't disconnect battery cables while the engine is running (your battery acts as a filter).
Don't put off recharging batteries.
Don't add tap water as it may contain minerals that will contaminate the electrolyte.
Don't discharge a battery any deeper than you possibly have to.
Don't let a battery get hot to the touch and boil violently when charging.
Don't mix size and types of batteries.