Lithium batteries do not last very long before they need to be replaced. Lithium batteries last longer than the older metal hydride batteries.
Machine BIOS warnings usually cannot be disabled. This motivated the removal of the battery and the machine relegated to desktop only use.
Many machines have a grossly inadequate power supply. The power load varies a lot in use and the battery acts as a buffer to level out the power load. If there is no battery present its possible the machine may shut down unexpectedly if there is not enough voltage when the load exceeds the PSU capacity.
The problem with using the battery to load balance an inadequate PSU is that the battery will wear out very quickly. Many articles over battery problems are due to the practice of inadequate power supplies. Replacement batteries are rather expensive.
Replacement chargers are available with a higher power rating. We strongly suggest upgrading the power capacity. A better power supply will extend the battery live especially with a heavy workload. For example, replacing a 65W charge with a 90W charger will make USB devices work much better.
Many machines can be upgraded with battery capacity as well. For example, a 6 cell battery may be provided by the factory and a 9 cell battery will provide 50% more mobile use. Combined with a better charger, the better battery will materially improve the performance for years to come.