LTO (Lithium Titanate) battery how do i go about charging them!
I was mentioning it out of interest for (sort of) cutting-edge tech, but frankly I wouldn't really recommend that for your simple project.
LTO batteries are not difficult to handle though. They are charged the same way as Li-ion batteries, only at different voltages and usually can take a much higher charging current for a given capacity.
So you basically need a constant current/constant voltage charger, and the constant voltage should be at 2.75 V instead of 4.2 V (for LiPo). Some chargers are available on the market that can handle multi-chemistry batteries. Or you could build your own charger, there are some ICs for that. Of course there are not many ready-made chargers for LTO batteries, so again, I would not recommend that for a small project. But those batteries are really great.