Very easy to install on my van batteries. After installation, the first fill seemed to go well and the bats took on quite a bit of water despite looking quite full. When the pear got a bit difficult to squeeze, I stopped. After 1 month I tried to fill again but the bulb kept draining from the hose and I couldn't pump water anymore. almost full. Need clamps to attach the hose to the bulb so I downgraded the rating and use from 4 stars. .