Batteries

For some EU countries where truck delivery is possible you can get battery cells directly from me. Otherwise I maintain a list of reputable online sellers.

Yes, a 18650 to 21700 adapter sleeve is included with every Ubik 21.

You need to use one of the battery cell models found in the official recommendations page. Any cell not listed there is not supported.

No, Ubik is not able to charge the battery cell internally, you need an external lithium-ion battery charger.

This is a tricky question to answer. But you can expect on average at least 4 sessions on a 18650 and 7 sessions on a 21700.