The difference between the Shark WV200UK(Single Battery) and WV251UK(Twin Battery) Cordless Handheld Vacuum Cleaners are the Charging Dock design and Battery design.
- The charging dock designs are different.
The Shark WV200UK charging dock has two slots for the included Duster Crevice Tool and Multi-Surface Pet Tool.
Whereas the WV251UK charging base has only one slot for one of the tools, because the second battery also stores on the charging dock, and this takes up the space that is used on the WV200UK to hold the second accessory.
So, there is no place to store both tools on the charging dock of WV251UK.
(Both of them come with two accessories.)
- Battery designs are also different.
The WV251UK battery has release tabs on the battery
cap for easy swapping.
Whereas the WV200UK battery does not have the release tabs, you will need to use coins as suggested in the battery removal and installation instructions to help remove the battery.
So, the battery design on the WV200UK (single battery version) is not something that you can buy a second battery and use it like the WV251UK (twin battery version).
But if you still want to do that, yes, it can be done, just requires a bit more work.