Batteries Mah

I have had my Samsung 18650 25R batteries for about 12 months now
I always use them and charge them in pairs.
Today after charging 4 of them in my Opus charger i checked the Mah after it said they were fully charged and they all read only about 680 but still 4.2v.
Im think they were 2400 when they were new.
My question is are they still safe ?
Should i try the discharge refresh feature on my opus charger on them or is it to late ?
They still seem to work ok in my mod but have noticed they dont seem to last as long.
Any advice would be welcome.

i have the Opus also…what I do is after say 3 charges…i then do a discharge and test an charge…keeps the batteries in tip top shape…its one of the better chargers on the market for the money…also charge at the lowest rate…that helps the batteries also

You get 300-500 charges out of them but they are still safe. You need to replace them when u get too frustrated that they don’t last long. I never read how that feature of your charger affects them so cant offer opinions.

I would be leary of them. 12 months old and they’re not holding a correct charge anymore. I would invest in a new pair. At least thats what Mooch recommends and he’s the battery guru of vaping.

when a battery starts being a trouble

a) they don’t last long as they should…
b) in my experience they’re not able to charge up to 4.2V but lower like 4.1V or 4V and if they’re done even lower (you could notice that mostly in batteries that are getting charged with fast charge… they need replacement much faster)
c) they get warm when they are in use (this is NOT a rule, but a battery after a times gets damage in overall… not capacity only or whatever)

if you’re really worrying for something i would say just change them… b.t.w. i am not also familiar with the opus charger… my chargers are NITECORE and Xtar…