I see a lot of negative reviews for this charger that I think are partially due to Amazon's incorrect description and the fact that most people don't know what size or type of charger they need. (including myself)I am a practicing Electronic engineer with more than 20yrs experience. I did not know much about battery chargers until recently researching what a good battery charger should do.1) this charger only delivers a max of 1.5A. This means if you try to charge a discharged auto battery (48AH) it will take a long long time. This charger does work great for topping off a car battery at 70% (12.4V).2) The instructions included clearly state the charger will automatically shut-off after 12 hours of charging. The charger will restart and continue charging if you unplug and then plug the charger in again. Best to get a higher capacity charger.3) This charger does have a float mode sort of. Actually it shuts off the charging current and monitors battery voltage. When the battery voltage drops low enough the charger cycles on to top it off and then shuts off again.MY SUMMARY 1st:I like this charger and think it does a good job for the PRICE. Gold box special was $15.20 + tax. (I would definitely buy it at the regular price for $3$)It's basically automatic. Don't have to set the voltage and it won't damage anything if you reverse the clips accidently. Compact size and reasonable quality clamps.This charger does what it is designed for. That is charge small batteries and top off larger automotive batteries. This is an excellent maintenance charger for all batteries to keep them fully charged when not in use. (My opinion)Personally I would not leave any charger connected to my battery for more than 24 hours. Now I use a cheap mechanical timer that is set to turn on for 1 hour every 24 hours. I would prefer a timer that I can set to turn on twice a week for a few hours.The charger is small feels solidly built with heavy plastic. It gets very warm aftercharging at 1.5A but not warm enough to be concerned. (no cooling fan)I gave this charger 5 stars because PRICE and performance is very good. Build quality is good as well.AMAZON DESCRIPTION (Poor): is incorrect in that this charger is not intended to be used to charge a LOW (discharged) car battery. The chart in the DESCRIPTION that shows the charging times is different than the manual.. The included MANUAL has a chart that states this charger should only be used as a "top off" or maintenance charger for auto batteries. In addition the charger in charging mode automatically shuts off after 12 hours of charging. (A good safety feature in my opinion.)Charging details:I discharged a car/truck jump start battery pack to 12.45V or approx 75% charge.(Typical full charge is 12.65V to 12.7V. To discharge the battery I used a battery/alternator tester. I have a voltmeter attached to charger and a current meter in series with battery and battery charger negative terminal.1) At the start of the charge, the charge current was 0.78A and then jumped to 1.52A in a few minutes.2) After 1 hour the charge current is 1.47A. Charge voltage is 13.0V.3) After 2 hours the charge current is 1.48A. Charge voltage is 13.25V.4) After 3 hours the charge current is 1.43A. Charge voltage is 13.46V.5) After 4 hours the charge current is 1.40A. Charge voltage is 13.82V.Note: that the charge current is decreasing as the battery is approaching full charge. This design feature will prevent overheating and extend the life of your battery.6) After 5 hours the charge current is 0.68A. Charge voltage is 14.71V.7) After 5.5 hours the charge current is 0.35A. Charge voltage is 14.67V.8) After 6 hours the charge current is 0.29A. Charge voltage is 14.73V.9) After 6.5 hours the charge current is 0.24A. Charge voltage is 14.72V.10) After 8.5 hours the charge current is 0.20A. Charge voltage is 14.73V.11) After 10.5 hours the charge current is 0.15A. Charge voltage is 14.71V.12) After 11.5 hours the charge is COMPLETE and the charge current has dropped to 0.0A. BATTERY voltage is 13.55V and declining. Charger is in the monitor mode. In monitor mode the charger AC power is 3W measured with a Belkin Watt meter.Almost 12 hours seems like a long time to charge a battery and this isn't even a full capacity car battery. But, it did a good job of gently charging the battery especially when it was near full charge. The important thing to me is the charging current declined as the battery neared full charge. This prevents overcharging and truly tops off the battery to maximum capacity.I tested the battery the next day with a battery tester and it passed well within the "good battery" full charge limits. The results were much better than the charger that came with the battery pack where it tested NEAR "weak".Very happy with the purchase. I would buy this exact model again. Should there be any problem(s) in the future I will update this review.Ships from and sold by Amazon.