This guy takes a look at battery his friend just had to replace. After a little dissection he finds it’s filled just a handful of cheap batteries. All that value must be in the sponge

here i take apart a £500 rechargeable battery for the Nagra IV (6) digital recorder to find Lithium polymers inside worth about £22.50
I think Its an expensive waste to purchase the box and circuit everytime a battery fails especially as they simply unplug. and according to the Nagra website Lithium-Ion battery packs will last for between 500 and 1’000 charge cycles.