for Milwaukee for M18 18V to for V8 Battery Adapter

Note: Your Battery Must Be New, Original and High Capacity.

Why does it require so much for your battery?

1. Our battery adapter is just a battery converter, it doesn't consume any energy or offer any power. Vacuum's work depends entirely on your battery;

2. Rated power for cordless tool is less than 200w, but for V8 vacuums is 500Watts. If your battery is low capacity,
it can't start for V8 vacuums. That's why your battery can power tools, but can't start for V8 vacuums.

3. Your battery must be original battery. As most replacement batteries' capacity are falsely labeled, and their cells are of inferior quality.
They aren't capable of working for V8 vacuum cleaner.

4.Your tool battery must be new. If it has been used for long time, even though it's capacity is 10Ah or more,
it's performance will decrease much and can't start 500W for V8 vacuum cleaner.

Why can't your vacuums work on high mode?

As both for V8 vacuums and original tool battery have protective function. Once vacuums is switched to high mode,
battery cell's discharge rate will be low and can't meet requirement, then it'll stop automatically to protect your vacuums and battery.
Just switch to low setting mode, it'll work normally.