Bangle & Arduino communication through Bluetooth?

one thing that puzzles me is this line g.drawString(" Batt:" + data, 1, g.getWidth()/2); which should display Batt:nnn where nnn is the value without leading zeros. On the Bangle 2 display is though instead shown b:nnn, so instead of " Batt:" is " b:" shown (lowercase b).

No problems when using the vector font though