Ask MetaFilter questions tagged with trickle

Charge a really dead battery, even if it damages the battery.

brenton — Mon, 08 Jun 2009 21:32:07 -0800

How can I recharge my nearly-completely-drained car battery so that it will work long enough to drive it to get crushed? I'm hoping to avoid buying a brand new battery just to have it crushed. My car qualifies for a $1,000 rebate if I crush it, due to some "gross polluter" laws. To qualify, I have to drive it to the crusher under it's own power, and it has to demonstrate that it can start up and run on its own. But I've been letting it sit unused for months. Battery worked before, but now it's dead. I tried jumping it, with the hope that after a 45 minute drive to the dismantlers, it would be charged up enough to start again.

But even revving at 3,000 rpm, I could barely get it to turn over once! And the jumper cables were hot after-wards!

I have to do this on Saturday, or I won't ever get to do it. Is there a tricky way to charge a battery, maybe a way that will ultimately destroy it but will work for a week or two? Can I get some old AC adapter and use it as a trickle charger? How much voltage can I run through it? If I overcharge it overnight, will the battery explode in my room?

Should I buy a solar trickle charger?

Mid — Thu, 08 Feb 2007 20:34:42 -0800

Car battery solar trickle charger -- fact or fiction? So I don't drive for like 2 weeks at a time. In the winter, this means dead battery. Googling around indicates that there are these solar "trickle charger" devices sit on your dash, plug into your lighter socket, and slowly charge your battery. Has anyone actually used one of these things? Did it work? I'm skeptical.

Example here.

How much exactly will using my laptop on AC destroy my battery?

qvantamon — Sat, 25 Nov 2006 20:20:23 -0800

How much exactly will using my laptop on AC destroy my battery? From what I've read, when the laptop is in AC with the battery inside, every now and then the battery gets below a certain threshold, and the computer tops off the battery (trickle charging). This "burns" a charge cycle, reducing battery life.

My question is: what's that threshold? and exactly how much time is this now and then? is it like once every five minutes, once every hour or once every day? And how is the effect in battery life compared to full cycles?

Justification: I use my laptop mostly at home, when I have AC always available. Right now I use it some 2 or 3 times a day, 2-3 hours each time. I really don't want to take the battery off, so, my decision is between plugging it on the wall whenever I'll use it, or alternating using it discharging the battery (until 10%) then charging again on AC (until 100%). I assume leaving it always plugged is not an option (I don't need it to be on when I'm not using it).

By the way, is there a problem if I leave the charger always plugged on the wall, even when it's not plugged on the computer?

If it matters, it's a HP Pavilion dv2000t. It was bought last month, so I think it should have all mainstream battery preservation technologies.