My personal experience is with an old cygo set up with a ni-cad battery. The Ni-Cad battery needs to be charged for 15-hours straight, no more, no less. So its always a hassle trying to time the recharge with fading power. Not to mention, 15-hours is an odd length of time, its easy to forget that its been plugged in, plus if it needs to be charged during the week, I have to remember to plug it in immediately after I get home or else I won't be able to charge it the full 15 hours, which screws up the battery capacity.