Let me tell you about my love-hate relationship with solar lights. I bought these GEILIENERGY batteries hoping they'd revive my sad-looking garden path lights that hadn't seen proper brightness in months.

The first thing I noticed was that cool little hole in the positive terminal - apparently for better cooling. My old batteries didn't have this, and after seeing how hot these babies get in direct sunlight, I appreciate the engineering thought behind it.

Installation was straightforward, though I did take the extra step of cleaning all my light contacts with some spray cleaner first. Out of my 12 lights, 11 sprang back to life like they were brand new! That one stubborn light? Turns out its solar panel was beyond saving - can't blame the batteries for that.

Now here's where it gets interesting. These definitely last longer than the original 300mAh batteries my lights came with. We're talking proper illumination from dusk till about 3am during summer months. But come winter? Don't expect miracles - they'll give you maybe half that time.

A word of caution though - these are slightly fatter than standard AAs. They fit perfectly in my solar lights, but I tried popping one into a Maglite just to test and... let's just say I had to perform some battery extraction surgery.

After six months of use, I can say they're holding up well despite being baked in the sun daily. Just remember to fully discharge them occasionally - treat them mean to keep them keen, as they say!