The chargers won't overcharge. The computer won't overdraw. I can actually set minimum voltage on my computer, I have it at 45v but could go down to 40v. I use Chinese computers, chargers and batteries on both bikes, never had anything miss a beat. Ensure your charger is double insulated (square-in-square symbol). I charge them in my living room, admittedly the plug socket is always switched off when charging is complete and i never charge when I'm out.