I have had it for about 5 years, maybe more, but I started using it about 2 years ago because I didn't believe it would work, but it actually helps. It is expensive now, I believe, but back then I didn't have many options. It doesn't charge it, it just keeps it from discharging if you have it idle for a while, whereas normally in 20 days you would need a new battery or discharge it. With this, it will last for about two days (assuming you already have a new battery, fully charged before the idle period, and as long as the solar charger is connected to the sun for several hours). I give it 1 star for the price. I bought it for 8 euros. It's not worth buying it for more than 15, it's better to spend another 15 and get a charger that will put you ahead in 10 minutes and fully charge it in 4-6 hours.