I have a 14-15year old 18v ryobi li-ion 2.4ah battery. I did a 1C capacity test constant current to 15v lvc, and got 87% of the ah’s. Also on a full charge on a drill it did alot of hard drilling in stainless 3mm sheet a month before so I know the battery is very much going strong. Its twin-another 2.4ah unit brought at some time died at age 10+, charger simply wouldn’t charge, never investigated sadly.
The older one has done about 50-80cycles and lived its life in partial soc.
This is very much identical to flashlight use.
So some questions.
Why has these cells lasted so long when others like my olight 3400mahs are down to 80-85% capacity in just around 3years? I keep them at 50% in a air conditioned bedroom, while the 18v battery lives in the shed!
Does this mean lower capacity like 1800-2400 last longer than high capacity?
Luck of the draw? I had a Milwaukee screwdriver battery last for 14 years and was still in pretty good shape.
I never could get another battery, even the same model number, to last anywhere close to that.
All the Best,
Jeff
It would seem a cell’s particular chemistry has a direct bearing on cycle times.
I had stumbled upon an article that mentioned some LGs weren’t very good in that respect.
Ryobi was, in its infancy, a great competitor to the professional line (Makita, Milwaukee (the original), Hilti, and to a certain extent, the DeWalts (when they finally upgraded to LiIon)). I would assume they chose a reputable battery supplier. After some time, they focused on the homeowner with more budget-friendly offerings. They would have cut costs and so the cells are ’probably lower specs.
On a side note, I’ve been using some Makitas for well over 15 years, and used professionally - earned a living with these tools. Just last year some were showing some fatigue. Not much battery capacity, but the Sonys at 1500mAh did test well over time. When the time comes, I’m looking into replacing them with VTC6s. Again, same chemistry as original cells but higher density. The newer battery packs have Sams 25R and a not too forgiving BMS - don’t like to be abused from the cold.