Make use of "old" batteries ?

[Planetcooler]

When your cycle battery gets too tired to power your bike - it may still have oodles of life left in it for other applications. I am currently using an old 36V battery pack to store daytime Solar PV generated electrons - to then feed DC domestic lighting at night. ( 3x12V LEDs in series to accept the 36V output). Better than using valuable excess PV electricity to heat water. Just a suggestion...before you bin/re-cycle that expensive battery.

 

[flecc]

Indeed, the same is true of spent car batteries, they have many years of useful life in them for other purposes than very high drain starting, something I've done for decades.