well, lesson number one is that you should keep your laptop plugged in unless you NEED to use the battery. draining the battery can happen when you run a bunch of CPU intensive programs without having the thing plugged in. sure, you're representing your boss, but i hope he knows that because that can avoid a bunch of calls to dell tech support.
i happened to have had a problem with my old computer where a tech support guy came 8 times in a 2 week period in order to replace various parts of my system. it was ridiculous, and since i wasn't home, he was coming to my office, and it just looked really unprofessional. stuff happens, i guess.
you really need to be very demanding with these tech support people, because half the time they don't understand what you're describing, so you need to emphasize that you want them to repeat what parts they are replacing, etc. and if you're calling a fourth time for a boot sector problem, then obviously you just need a new harddrive and need to tell these tech support people flat out (don't be an idiot and fall into their trap) that if you don't get the proper help (e.g. a new harddrive) in your next shipment, you'll call a supervisor and have the phone rep's name ready to file a complaint (make sure to get that name!)
seriously, tech support sucks, but aggressiveness is very critical or else you might as well not opt for tech support anyway because you're not benefitting from it.