There are two ways to check how many uses you have left: On the IQOS Holder Press and release the button on your IQOS  Holder:
Two lights mean it’s ready for two uses One light means it’s ready for one use No light means the Holder isn’t charged, simply charge it for more uses.
On the IQOS Pocket Charger Press and release the Pocket Charger button:
Two lights mean it’s ready for two uses One light means it’s ready for one use
On the IQOS 3 DUO Pocket Charger                                                 On the IQOS 3 Pocket Charger* * If you use the IQOS 3 DUO Holder in the IQOS 3 Pocket Charger, you might need to upgrade your IQOS 3 Pocket Charger firmware so it can tell you when the Holder is ready to be used once.