suggestion for Electrolux to avoid E:21 on new robots
The pure i9 manual states quite clearly, that the unit should be stored for longer periods of time with the batteries removed. Shelf life in a store / warehouse can be quite lenghty.
So, in order to avoid the dreaded E:21 messages on new units (the forum here has quite a few of these complaints) Electrolux should think about shipping the units without the batteries installed or at least with a "breaker" strip like iRobot does with its Roomba units (a small strip of plastic you have to pull out to let the current flow from the batteries).
I'm the proud owner of a pure i9.1 since December 2019. I charged the unit on arrival until it quite quickly pronounced "I'm ready!". To my dismay it stopped after only a few minutes of work with the red battery light on. On the charger it then presented E:21 which tells me the batteries are "dead".
Luckily the unit has recovered in the following days and now shows the standard (short) operating times of about 40 min or 60 min (in "Eco" mode)
I think, all this frustration could have been avoided, if Electrolux would ship the units without the batteries fully connected to the unit and thus avoiding deep discharge of the cells during warehousing.