Harmful. There are heavy metals in batteries, such as lead, chromium, cadmium, etc. Water contaminated by used batteries is therefore essentially water contaminated by heavy metals.
Heavy metal pollution can cause various diseases, including cancer, leukemia, heavy metal poisoning, etc. But you should be able to excrete it slowly through your own metabolism.
Strictly speaking, water is a non-renewable resource, while fresh water is a renewable resource.
Water is indeed renewable, but that does not mean that it is a renewable resource. Because you can get water by igniting hydrogen into oxygen, but from a resource use perspective, the amount produced is so small that it is negligible and insufficient to be used as a resource , water is therefore a non-renewable resource.
Fresh water and waterhave two different resources in many situations, because water in the broad sense includes seawater and freshwater.
It is different when it comes to fresh water. Atmospheric circulation, snow and precipitation can convert seawater into fresh water that humans can use as a resource.