Hi all, this is my first post! In my opinion, leaving it powered up while recharging is fine short term, but it will reduce the overall lifespan of the batteries, because it's using energy (you will notice it stays warm) and is therefore constantly recharging. I have used mine this way (lightly) for 3 years and the batteries recently died. I have many other devices with lithium batteries that are lasting much longer. Hugo 2 has addressed this issue by going into a sort of 'battery bypass' mode after 24h of being idle on the charger. Second point; deep discharging has no benefits for lithium batteries and, according to what I've read, it's actually better to recharge more frequently (i.e. 2000 recharges from half capacity has less impact on life than 1000 recharges from fully drained). So, from now on, I intend to leave mine connected to the charger when not in use, but turn it off. It doesn't take long to warm up again. Staying with batteries, I wanted to share some information with my fellow Europeans regarding sourcing replacements. When I did my research, I found the info on battery type and OEM easily enough, but couldn't find advice on where to buy. I found out that they are distributed by RS components and the stock number is 615-2472. Most countries in Europe should be able to order from there online. Price varies according to country, I paid £46 for the pair including tax & next day shipping. A good saving on the Chord fee of £150 including labour, and much faster. HTH Disclaimer: I do NOT advocate DIY battery replacement and anyone who chooses to replace their Hugo batteries personally does so at their own risk. The task requires a low powered soldering iron, with a small tip, and sufficient skill to be able to use it. The battery contacts on the PCB are very close together; it would be easy to create a bridge, cause damage etc. if the job is not done with the right equipment and utmost care! I only did mine by myself because it had gone out of warranty, and I happen to posses the necessary skill & equipment.