What type of battery is used in the SK636 and SK638? Where can I buy replacments?

Our lights use the standard size of 6V DC 4AH or 4.5AH rechargeable sealed lead acid (SLA) batteries. You may also be able to use a 6V DC 4.5AH battery, as long as the size is the same as the 4AH one.

These batteries can be purchased at most local hardware stores.