Yes the battery is a significant part of the weight (4.5kg I think). Fortunately, I don't envisage needing to carry it very much and will avoid getting into situations where I will have to (until I've done enough strengthening exercises and look like Gina Carano!)
Ms Carano is one mean non-mother! I expect she does the exercises all martial artists do, plus oodles of weight training at the gym. Start with a weight at the gym which you can easily raise and do 10 repetitions of that, do that three or four times. This warms up the muscle, so that you can break it down more effectively and force your body to replace muscle fibres with stronger muscle, which is fast twitch muscle, as opposed to endurance muscle, which ladies have more than men... which explains why women are naturally better at endurance exercises than they usually are (without training) at lifting heavy weights. Once the muscles you want strengthening are warmed up (arms for lifting bikes), increase the weight so that you can just about do 7 of that weight, doing the same exercise. Do that three or four times. Rest. Then increase the weight to the heaviest that you can do 5 of, and do that three or four times and rest. Then pile on more weight and lift as much as you can do 3 repetitions of. Rest a bit. Then lift the heaviest weight you can possibly lift and hold that weight at the most stressful high point of that lift. When you can't hold it any longer, put the weight down. Rest. Do that until you cannot lift that very heaviest weight. Then consume as much protein as you can for about a week (strengthen every week, if you are new to strength training), before you do all that again. Make Sensei Carano proud! And be very very careful, you can injure yourself very badly by following the above instructions, especially if you do it in a cold room. Best hire a personal trainer. You'll ache like mad. If you warm up properly, you won't get muscle strain. If you lift too heavy a weight too early, your muscles will spasm. A bit of pain is good for you
p.s. You can kill yourself by doing the above if you have heart problems, high blood pressure, diabetes or any of quite a long lost of other medical problems.