If I want a stronger energy drink can I just put more scoops in my bottle?

Do you mean with ‘stronger’ higher in carbohydrates?  This depends on two things. If the drink also contains electrolytes then the prescribed amount will provide you with the right electrolyte balance, it is normally safe to make it a little stronger, however increasing by too much might make the concentration of electrolytes so high that it could have the opposite effect i.e. it might draw liquids from your body towards your intestines where the strong electrolyte mix sits.  

If your energy mix consists of just carbs in theory you can make it as strong as you want, however your body won’t be able to digest/absorb much more then 90g of carbohydrates per hour.  What type of carbohydrates are in your drink also matters as some are more easy to digest as others.  High fructose levels are often the cause of GI distress (Gastro Intestinal).  Equally simple sugars like glucose and Sucrose although quickly absorbed in lower doses are less well tolerated in high doses then more complex mixes with Maltodextrin and sticky rice starch.  Not everybody is the same, so practice with different types and strengths and perhaps slowly increase the amount of carbs if experimenting and try it out whilst training…what works for your training buddy might not work for you!