with that budget u already can get AFTERSHOCK XG15 V3 that comes with GTX860 2GB GDDR5

if this discount Lenovo Y510p, i7-4700MQ + Nvidia GT755M(GDDR5) + (1920x1080)@RM3399[2.7kg], 8GB, 1TB, W8.1, red backlit, swappable ODD, 120w psu, 2 yrs

might be in ur budget range..

If you don't like Acer and afraid of it's warranty service, Asus is even worse than Acer.. Asus provides well known bad service.. mostly.

Acer V Nitro is your best bang of buck if you're looking for a decent GPU.. GDDR5 is better than GDDR3 in performance.. If your gtx850m is GDDR5, it won't make much different compared to gtx860m GDDR5.. just roughly 20% lower performance than gtx860m. If it's a gtx850m GDDR3, then the performance is significantly lower.. so get gtx860m if the gtx850m you referred to is a GDDR3, else no need

And 3 cells doesn't mean the battery capacity is low. 3 cells mean the battery will draw lesser power / supply lesser power to the laptop compared to a larger cells battery. But mostly bigger cell comes with bigger capacity.
For your requirement, you're not gaming a lot, and also not doing too much designing work, so why aim for budget gaming laptop ? Your Engineering 3D design is using what software ? you sure it is depending on GTX CUDA core and not Quadro ? GTX series is not good for 3D rendering, it will be quite slow.. (correct me if I'm wrong)

For MatLab, if you're doing heavy stimulation, get AT LEAST 8GB ram. I'm a MatLab user and developer also. Software Programming depend on what you're developing, Android Studio and Visual Studio requires about 1GB ram each.. Mine is 1.5GB as I use a lot of plugin.. 

IMHO, cpu power is more important that gpu in your case.. since most task you listed out requires lot of cpu power..

You can try out AFTERSHOCK or ILLEGEAR. These 2 brand is using Clevo model which is well known for its built quality, pm Prince J to get a quotation..
Both these brand laptop battery capacity is good.. My ILLEGEAR Z5 is 8 cells. It lasted me about 3-5 hours on normal web surfing, med-low brightness.. But it's out of your budget 

No need.. I didn't keep promote ILLEGEAR pun.. I just don't want ppl kena tipu like my friends.. Get MSI cuz of the marketed Cooler Boost is very good.. in the end....
And Lenovo very solid, in the end my friend's casing got problem.. need go through warranty.. first week sia

None can last 5yr.. 5yrs only precision, latitude n Alienware for dell.. xps oso 4yrs like tat nia

Custom build easy to maintain... but not sure the lasting... gaming should be OK.. ur budget?

Any recommendations for laptop below 2k, not for gaming ...

Where do u find 2859 for Insiporon 7447 ? Is it the Full HD version ?