ORIGINAL: guver
On the battery my thiking is that if it likes the extra weight then it might as well be inside the front tires instead of high up in the chassis, does that make sense?
Buy motorcycle wheel weights! There all stamped with there weight values, and there self addhesive. Just stickem inside your front rims so they are balanced, 2 opposite of eachother, 4 across from eachother, and so on...
I use a 3cell lipo in my maxxcrawler and needed to add 8 wheel weights in each front rim, making 16 in total, at 25 grams each, adding 400 grams to the front end to pull me up the stairs nicely.