I do not write reviews but I wanted to circle back on this one and give it the praise it deserves. The charger has helped me so it may help you.I purchased it because I accidentally killed the battery in my expedition vehicle. The battery in question is an Odyssey 31M-PC2150ST. I left the keys in the ignition for over a week while camping (oops... whiskey may have been involved) and it was dead to rights when I tried to crank her on... nothing, nada, not even a peep. I jumped her and drove her home cursing the sky that I would need to replace the $450 battery... ya, that is what they cost.Once home I tested the voltage to inspect the condition of the battery... 5.9 volts... hmm, not a great read on a battery that when healthy reads in the 13 v range. However, it is a deep cycle so....maybe?! I looked into chargers that specialized in recovery and that is what brought me to this charger. It did take 3 FULL DAYS to bring the voltage up to a respectable level but after load testing guess what... the voltage held. I have been using her now for about 6 months and she continues to act normally, charge normally and still kick a$%. AWESOME.Fast forward a few months my girlfriend does the same thing... keys overnight this time but she has a standard battery... some Duracell variety in her Pontiac GTO. DEAD. Voltage test = 3.9 v. Yikes! Mind you, mine was a deep cycle... hers was NOT. I told her we would need a new battery but just for giggles I hooked her up to the charger for a recovery attempt. 3 days later... BAM! Like batman laying the Wayne down on the Joker she was put in line. The battery is running perfectly. I honestly don't believe it after such a deep discharge on a standard, flooded cell car battery.Final thought: Get it if you need to recover deeply discharged batteries and/or otherwise perform routine battery maintenance.Does it take a while to charge? Yes. If time is a factor for you there is a pricier version that works faster for about twice the cost. I do not mind the methodical approach.