discharge and recharge lithium ion batteries

[youngbuckwithapickuptruck]

I have four 4ah 18v ryobi batteries that have been sitting at ~80 charge for the past 4 months. I hear it helps extend battery life to discharge the batteries and recharge them. is there an better way to do this then just saw at a tree stump with sawzawl for an hour?
also should i just drain them down to 50% or should i completely drain and recharge?
i have a slow charger i can put them on if that helps.

 

[alwaysFlOoReD]

The new batteries I just let the charger work it's magic. The old batteries from 2 decades ago needed discharged and recharged, I don't believe the lithium ones do.

 

[BroncLander]

Aren't most chargers now intelligent and know what to do to optimize the battery?

 

[mikkelstuff]

I learned the hard way that lithium-ion batteries should never be totally discharged - unlike those NiCad batteries. The lithium-ion batteries are unlikely to recover if totally discharged. Just put them on the charger as is.

 

[youngbuckwithapickuptruck]

charger does not know if your next battery use will be in 3 hours or 3 months

 

[scotts90ranger]

Lithium batteries are best stored at 50-70% charge state so I wouldn't sweat that at all...

The NiCd and NiMh batteries of the past were a pain, NiCd were pretty durable although had not much charge capacity, NiMh had better charge capacity but they decided not to be batteries when they felt like it... Lithium batteries need fancier chargers but treated right can take some beating and last fine.

The charge cycling thing was for NiCd and NiMh batteries as they could take a "memory", lithium batteries are rated for a certain amount of charge cycles but don't take a memory other than losing capacity over time/cycles