He runs his tank dry without noticing at work . So he needs a bigger tank . And even without running his tank dry he goes through coils like every other day
Well the Kanger tanks are getting to be regarded as sub-par tanks more and more.. I had an Aerotank V2 for a while, loved it, but moved on to better ones.
As for as running his tanks dry without noticing... he needs to really consider going with Temperature control (TC), which prevents dry hits/burns.
I believe that there is a RTA for that Kanger tank, so he might want to consider looking into that, get some proper TC metal wire and make some coils (and cotton/wick).
And he can easily bring a bottle with him... but again, he might consider getting a top fill type tank... as I'd assume that refilling his tank is part of the problem.
Getting something like the Eleaf Melo 2 (or Lemo 2), or most OBS tanks that have sliding fill doors, makes them the easiest tanks to refill, heck, you can refill them while walking.
There's also the Freemax Scylla tank that's a top pop fill, very easy and nice, and you can get it with the RTA too. (and it still takes the "standard" coils cartridges that you can cross-share with about 20-some tanks.)
And going through coils every other day.. if he burns them.. yes, that's kill a coil. Also, lots and lots of liquids from stores have so much sweeteners that they are known coil-killers... they gum up the wick and coil very quickly, especially if he overheats it.. again, TC would help a LOT.
For example, I now do my own liquids, almost only use TC, and regardless of coils on RTAs, Drippers or Cartridges, they last for weeks, even over a month each.