You might want to start by getting some 'mega'
batteries. They are slightly longer but have about twice the life. There are several places to get them. TW is one place, if you're not concerned about price. Heaven gifts is another, if you're not concerned about wait.
You can also use KR-808 batteries with a 901-510 adapter. Those last quite a while as well.
Also, there are lots of BB mods out there if you don't mind size.
I can heavy vape my chuck for 2-3 days between charges.