First you have one of the best atomizers made. The battery doesn't live up to it. 1 -1.5 hours tops if you're over a 1 pack a day smoker. It's usually too confusing to recommend mods to new members but what you're running into with the batt is pretty normal when, like Scott says, we all tend to powervape at first - even for a few months. This is esp. true if you're at too low of a nic level with your juice.
You can get more batts - probably 2 more would keep you vaping without the possibility of running out. Or you could get mega batts for the 510 that last about 2 twice as long - you could probably get by with one of those on top of the 2 regular ones. If you have no consideration that it has to look like a cigarette, then I'd suggest taking a look at this video:
http://www.e-cigarette-forum.com/forum/video-reviews/43943-bartleby-pv-review.html
And then my post further on down the thread here:
http://www.e-cigarette-forum.com/forum/video-reviews/43943-bartleby-pv-review-6.html#post732483
... where I suggest what is needed for someone without a kit. You'll only need the charging cord and a wall and car adapter from cignot.
Just to get an idea - batteries are rated in milliamp hours - mAh
Your regular batts are 150 mAh
Megas are 280 mAh
The 14500 in the Bartleby is 900mAh. I've had one last a day and a half and I was the three pack a day smoker. I also was hitting another ecig with another flavor during that time but I usually have about 5 flavors going ;-) So for that 'test' I laid off the others. Normally I only have to recharge it before going to bed and it lasts the whole day without recharging.
The other aspect which you mention is how you are getting good hits right after recharging. You could go to batteryuniversity.com and see the graphs on voltage use but that initial charge for a 3.7V battery is almost 4.2V (4.1x) and the more mAh's you have on the batt, the longer it holds that higher voltage charge - so rather than a minutes for the regular 510 batt, with the 14500 you are holding that voltage for hours before it drops into the 'average range'. That..... makes quite a difference not only in vapor but how much nic you're getting.
Just this week, (after 5 months of vaping but after a month of having the Bartleby) I've noticed I'm putting it down more than I was with the regular ecig batts or even the megas.
There is so many pluses to mods - in the event of a ban - the batteries can be had anywhere. The only things you will need are atomizers and juice. I could (and just might) sell my stash of 510 batts and megas. I take the bartleby whereever I go. I have no consideration on how it looks. it fits snuggly in the palm of your hand. It would be a 'stealth vape' were it not for the amount of vapor it produces - as someone pointed out ;-) The insides are epoxied so no worry about dripping on the atomizer although with the 510 2 drops is plenty.
The only thing you might change is the cart filler. The easiest is as Robert points out PTB - Lipton Pyramid Tea Bags mod:
http://www.e-cigarette-forum.com/forum/cartridge-mods/34401-ptb-plug-full-510-cart.html#post527318
Use the second one - the 'folded top' I make two folds (the juice goes to the folds) and then wrap it around a toothpick with the folds on the outside, that way the center is smooth and the atomizer goes right in the center and is surrounded by juice. It looks like it would leak but it doesn't as he demonstrates in the video. No straw, no plug (although later you might want to look up and try the 'plug mod' - I have a few of both). And while the bartleby with a 510 atty will suck up the juice (ie more vapor) it will suck it dry. And you won't have stale juice building up at the bottom of the cart well.
My guess is if someone went this way they'd be dropping nic level after a month, because for a while you'll still be power vaping.
The Bartleby goes for $50 much less than most other mods and you get two 14500 batts. Those batts go for about $3 for a pack of 2 some places. You don't need a charger because the charger's built in and you use that charging cord off a usb wall plug (watching tv) or car plug while driving - another thing that you'd have to pay extra for most other mods.
OR you could buy a couple more 510 batts and make that move 4 months down the road like I did. lol But - you have the right atomizer for it. It's as if the 510 atty was made for this mod.