I do this constantly: When I am watching videos or doing something that can drain my laptop’s battery really fast, i take out the batery and leave the laptop connected. Is this good or bad?

it’s the best! assuming you’re not working on anything (that needs to be constantly saved), it’s the best for the battery.

I asked this because I got a pair of Energizer rechargeable batteries but after a couple of months, I misplaced one of the pair. Since I have a charger that requires at least two batteries to operate, I was unable to charge my single battery. So I bought another pair of batteries but this time, its brand is Eneloop. Now I can charge the Eneloop batteries but is it possible to still use the Energizer batteries using one Eneloop battery. I thought of it since they both have the same rating (2000mAh). Thanks!

Look for the appropriate battery
http://www.digital-camera-battery-charger.us/
http://www.jvc-battery-charger.com/
http://www.panasonic-batterycharger.com/
http://www.nikon-battery-charger.com/

I have 2 12" Kicker Comps with a Kicker 500 Watt Mono Amp. My battery drains and makes my start up on my truck lag and i have to give it gas in order for it to start up. Should I get another battery, alternator, or better battery like a optima. I have a duralast yellow top right now.

That setup should not be draining your battery that much, i would check for shorts somewhere. Also, if the battery is old i would replace it before doing something more expensive like changing your alternator. Take the battery to you local auto parts store, they will tell you if its still good.

I was planning to get a battery pack and charger for my xbox 360 controllers but I was wondering if it’s worth and what the battery life is, or if it’s better to just get a battery charger and rechargeable AA batteries.

dont use those. get a battery charger and some duracell nimh rechargeable batteries 2000mah and up. you wont regret it.