What do you mean by first batch? If you just got the grains, you need to do 2-3 24-hour fermentations (or more as necessary) to allow the grains to “wake up” and begin growing at a decent rate. Pour the kefir away until the grains are ready because it’ll contain too much sugar. You’ll know when they’re ready because they’ll grow by 90-200% and some may float to the top. Other signs are carbonation, change in colour and, of course, sour taste.
If you’re not getting good growth, you need to add a source of minerals. I use a tsp of blackstrap molasses and 1/8 tsp of pure baking soda. You may need to check your water too. Tap water contains chlorine and other junk that won’t allow the bacteria to grow. I use bottled mineral water. Everything you need to know is on Dom’s Kefir Site.
If you get a reaction no matter what (remember it could be die-off), just eat the grains. The kefir itself has a number of benefits, but the grains contain plenty of (if not more) probiotics, and since water grains grow so rapidly, you get enough to justify the effort/expense of the fermentation process. I recommend eating them regardless. You’ll have so many anyway, so you’ll need to work out something to do with them!
By the way, if you chose water kefir due to lactose intolerance, read this article. It may be overcome by the very thing you’re avoiding! If casein is the problem, then continue with water kefir.