Tablet battery

[SNN4815AA]

I own a small grocery store and we open 7:30am-12pm. There are a lot of transaction but small volume, and the screen might be on all the time. So I wonder how long tablets will last with their chargers connected.
Did anyone have a problem with tablet's battery?

[VanKalkerFarms]

Our ipads will last around 6-8 hours unplugged and with the charger connected obviously it'll last all day.  You should definetly try and get it set up with it charging all the time so there are no hassles of dead batteries.

[brju2013]

We just did an event this past weekend 8a - 5p. The iPad lasted all day. We just turn down the brightness a bit, other than that we leave it on.