Tell me why this is a bad idea

I would like to significantly increase the range of my BGT, my current plan is to get a new battery made to replace the stock battery plus a bunch of additional cells which will be mounted on the top of the deck with a strong waterproof enclosure. This top enclosure will be positioned between my feet so I don't think it will get in the way. I plan to use the stock BMS and get it rewired to the new cells. The pic below shows the rough position of the top mount cells. The only downside I can currently think of is that I would totally void my warranty and secondly maybe the the top cells would get in the way if I ever needed to kick. Thoughts? Alternatives?

 

Not a bad idea for extended range BUT think you should wait until warranty is up unless you have super confidence that you won't have any problems i.e. remote, motors, BMS, etc. If you don't care then go for it and keep a build log and share results

 

Thanks guys, I'm not stressed about the warranty, I had an ideas today that maybe I should just be trying to fit a carbon battery in instead of a custom one. Just thought it may end up cheaper.