Well, true, 110 volt ac current is more dangerous than a wall wart's output , but a circuit like this can't be THAT dangerous, can it? More so than an old incandescent lamp? I know people who lost their houses in fires caused by old wiring, but a little circuit like this properly insulated, monitored , and kept away from flammable objects and enclosed spaces... is it really that much of a problem? Of course, one should always be careful around ac c urrent, but are there any other flaws in this circuit design? Tim mentioned charging at too high a voltage, but the article says the battery will draw just what it needs. Is that not true? Also, I've read that charging at a s lightly higher voltage and a very low current for a long time is a good way to desulfate a battery. As for leaving it on too long like Mike mentioned, I could just attach a timer. (I do know that there's a second phase to cha rging lead acid batteries, the constant voltage phase with auto-shutoff whe n current falls to a certain level. For this, I'll use a readymade store-bo ught charger.)
See, the thing is, I don't like the cheap battery chargers I can buy, and t he expensive good ones are out of my price range. I have a 6v/12v Schumache r right now, and it will only do 2, 4, or 6 amps. This whole thing started because I wanted something that would charge at whatever amps I want. If I could vary the voltage too, that'd be ideal. I like the pulse idea, though some say that's not what actually desulfates batteries. My Schumacher goes into 2 amp trickle charge mode after shutting off. I'm trying to squeeze so me life out of old lead acid batteries, so I want to overcharge but on a lo wer amperage to reduce sulfation. All I need is a little electricity at nig ht, and an old car battery that came with my trailer was working fine. (Yes , the previous owner replaced the deep cycle with a car battery. I deal wit h what I have.) I just want to desulfate it to get more useful power out of it and extend its life.
Finally, Fred says a dimmer switch will work, but Tim says it will always g ive too much current or none. Is it that the heater combined with the dimme r will make it work?
Thanks.