My new bike, a 2021Trek Powerfly 7, has a 625wh battery. A big improvement over the last Powerfly I had with a 500wh battery. Or is it? The 625wh battery weighs over 4kg, a good 1.5kg more than the 500wh battery and a good 2kg more than the 400wh Shimano battery on my wife's bike. I always use...