Advice on powering a robot

Hello... I plan on building my first-ish robot with these components:

  • LIPO 3.7V 6600 mAh
  • 2 x Micro metal motor 3to9 volts; HP; 100:1 ratio; 320 rpm; 1.6A max; www.tme.eu
  • 42 mm wheels
  • DC-DC booster IN:2.9to12 OUT: 12v;5A www.tme.eu
  • Ardumoto motor driver www.sparkfun.com; limit to 9V through PWM so i don't damage the motors
  • charger www.sparkfun.com
  • btooth

Should I: buy higher voltage batt + charger (more expensive) or boost 3.7v battery as planned(cheaper)

What would be some of the pros and cons between the two?

Or buy another same type battery and use same charger.

Use two in series.

Weedpharma

i've read on adafruit that wiring them is series or parallel is not recomended(something about them not charging in a balanced manner). Is it really a problem or is it just minor stuff? Would they both be able to charge fully?

Therefore charge them individually.

I’ll leave it to others to comment on running them in series. If they are both fully charged they should be balanced discharge.

Weedpharma