Skil HD529401 Owner's Manual page 82

Battery leakage may occur under extreme usage or temperature
conditions . Avoid contact with skin and eyes . The battery liquid
is caustic and could cause chemical burns to tissues. If liquid comes
in contact with skin, wash quickly with soap and water. If the liquid
contacts your eyes, flush them with water for a minimum of 10
minutes and seek medical attention.
Do not let gasoline, oils, petroleum-based products, etc . come
in contact with plastic parts . They contain chemicals that can
damage, weaken or destroy plastic.
Do not touch the uninsulated portion of output connector or
uninsulated battery terminal . There is a risk of electric shock.
Replace battery pack if a substantial drop in operating time per
charge is observed . Battery pack may be nearing the end of its
life.
6