I have a chance to buy an 8 cell Li-ion battery for a portable Dell for a good price. The battery is old (about 10 yrs) but is still in original package and has never been used. Given that it has never been used, is it worth buying?

Thanks

 

$5 is a good price for it.

 

If it's cheap it's worth a try.

It could take daily use for a couple of weeks before it gets up to whatever it's best capacity is.

Charge it fully and run it completely down each time to condition it.

Note that being left idle while fully charged, and hot conditions, are the worst state for Lithium batteries.

I always leave laptops on standby so if I don't use them for a while the battery is slowly flattened.

Leaving them permanently on charge is far worse than flattening them regularly..