Wesley, can you let us know how often you sharpen your blade? Also, grass conditions will drastically change your run time. Dry grass vs. wet grass. Tall grass vs. short. Dense grass vs thinned out. Also, ambient temperature.
How was your battery stored over the winter? Where is the battery stored when not in use? The one thing I haven't seen much about the EGO battery pack is that they are losing much performance for the 2nd year.
That's a lot, I know. It could quickly point out if it is an environmental issue, or truly a battery issue.
Its a power tool, leave it in the garage like any other power tool. If it doesn't hold up like it should, warranty exchange it. You should not have to go to extreme lengths to get a battery to last for years. Its ideal yes, but you should get at least 35 minutes of use without any kind of "special attention". If not, have them replace it. Don't sweat the small stuff. It either works, like any other battery powered power tool, or it doesn't. Don't over stress anything, if its not performing let the company handle it. Thats why you have a warranty.
If that is the case, there's nothing wrong with the tool and replacing the battery will not correct the condition.
Now it's a completely different situation if last year the tool lasted for 40 minutes, the user has done their due diligence regarding blade maintenance and cut conditions, and now the battery is only lasting 25-30 minutes a year later.
Also, Ego recommends the batteries be stored in an environment less than 80F. I'm sure exposure to temps above that are not going to cause immediate permanent damage, but at the same time one should not expect to get a maximum useful life from their packs if stored in an environment that is consistently well above that temperature.
I have to agree with the side that's saying that we should not have to 'baby' lawn cutting equipment. The mower advertises 45 minutes of run time. This should be an average. I would expect to get no less than 40 at any time really. No matter how I stored it and no matter how often I charged and used it.
Having great customer service is a must but the idea is to not how to actually contact them if the product is done right.