Bests & Worsts Reviews from Amazon

The other long review stating this is not a charger and will damage your battery if left on too long is 100% correct. I'm an electrical engineer so know this for a fact. There's also no indicator for full charge so unless you have a voltmeter attached and are ready to stop it, it will overcharge. I used it and became very concerned when it exceeded 15 volts, which it should never do on a charged battery. Given it's meager output of 500mA, you will have to watch it for a long time if your 2 AmpHour or more battery is discharged even 20%. This kind of misleading sales tactic should get the seller barred from Amazon. It's not just a product failure, it will destroy your battery and cost you far more. Shame on Amazon for declaring it a Best Seller.