Duracell DPP-300EP The minor details

This is a great product with a superior AGM battery as opposed to the other brands which have lead acid batteries. Some minor details include only being able to attempt to start your engine for 4 seconds. You have to wait 3 minutes before each try so as not to overheat the product. Also, the manual states you cannot leave the unit always hooked up so your car keeps it charged. Don't really know why. The air pump has a PSI gauge on the back that goes all the way up to 250 PSI which is not very useful as most people will only need the first half inch of the gauge for filling up tires. And lastly, the manual states that you should not use the AC power outlets while the unit is charging from your car. If you have any ideas why the manual is so paranoid about these things please leave a comment.