To better use your COMPAQ PRESARIO V4000 SERIES battery, please take care of the precautions listed below :
1. The simplest and most obvious way of getting the maximum life out of PRESARIO V4000 SERIES battery is to ensure that it always works well within its designed operating limits. There are however some further actions which can be taken to increase the battery life.

2. Do not modify or disassemble COMPAQ PRESARIO V4000 SERIES battery, as the materials inside may be toxic and may damage skin and clothes.

3. Caution must be given to prevent accidental short-circuiting of COMPAQ PRESARIO V4000 SERIES battery.

4. Avoid placing batteries in water or other moist device, as this may cause the battery to fail.

5. Never insert COMPAQ PRESARIO V4000 SERIES battery with the positive and negative poles reversed as this can cause permanent damage to the battery which may swell or rupture.

6. Never charge with an unspecified charger or specified charger that has been modified. This can cause breakdown of COMPAQ PRESARIO V4000 SERIES battery or swelling and rupturing.

7. Never reverse charge or overcharge with high currents (i.e. higher than rated). Doing so causes rapid gas generation and increased gas pressure, thus causing batteries to swell or rupture.

8. Do not place COMPAQ PRESARIO V4000 SERIES battery in device for a long period of time if device is not being used.

9. Store COMPAQ PRESARIO V4000 SERIES batteries in a cool place and when in use don't allow them to remain in environments which may be subject to overheating.