battery chargers, again
in [Design]
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From: krw on 28 Sep 2009 22:43 On Mon, 28 Sep 2009 17:39:24 -0700, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Mon, 28 Sep 2009 19:28:39 -0500, krw <krw(a)att.bizzzzzzzzzzz> wrote: > >>On Mon, 28 Sep 2009 09:06:34 -0700, John Larkin >><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >> >>>On Mon, 28 Sep 2009 09:04:17 -0500, Tim Wescott <tim(a)seemywebsite.com> >>>wrote: >>> >>>>On Sun, 27 Sep 2009 21:16:46 -0700, John Larkin wrote: >>>> >>>>> Last time a car went dead in the garage, my wife's Fit, I hacked up a >>>>> charger from an old DSL wall-wart and a sabre saw as a series current >>>>> limiter. The garage geometry makes it essentially impossible for us to >>>>> push a car uphill to the street to jump it. Now The Brat left her Echo >>>>> in the garege for a month or so and it went dead, too. So I figure it's >>>>> time to buy a real charger. Went to Kragen Auto Parts and bought two >>>>> (one for here, one for Truckee) chargers. They are all "smart chargers", >>>>> namely switchers with electronics, these days. >>>>> >>>>> The battery is really dead, 1.8 volts. The first charger hums and >>>>> outputs nothing. Tried the next one: it hummed for maybe 3 seconds then >>>>> sparked and smoked inside. >>>>> >>>>> Went back to Kragen and traded up, two better chargers. Neither >>>>> charges... no current, battery steady at 1.8 volts. Both have their >>>>> "charging" LEDs off and "charge complete" LEDs lit. >>>>> >>>>> Back to Kragen, 3rd time, got all my money back. Passed by Bob Pease's >>>>> place all three trips, same collection of rusty VWs everywhere. >>>>> >>>>> A charger that puts zero amps into a dead battery does that by design, >>>>> and there's only one reason to do that: to convince people they need a >>>>> new battery. Kragen's sales pitch was exactly along those lines; "Tt >>>>> won't charge, so all the cells are shorted." >>>>> >>>>> So I went to work and nabbed a cute little Lascar bench power supply. It >>>>> current limits at 1.2 amps, so I just cranked it up. The battery went >>>>> instantly to 16.5 volts, then settled down to 12 or so in a few minutes, >>>>> and is creeping back up. >>>>> >>>>> Interesting. >>>>> >>>>> So I guess I'll buy a couple of 3 amp or so lab supplies, with nice volt >>>>> and amp meters, instead of battery chargers. They're handier to have >>>>> around anyhow, cost about the same as a "good" charger, and aren't booby >>>>> trapped. >>>>> >>>>> What Kragen is doing is fraud. >>>>> >>>>> John >>>> >>>>I've never had a battery come back from being that dead, and I've had >>>>numerous chances to try it (I'm stubborn that way). You'll be lucky to >>>>see 12V out of it with the charger disconnected, and I doubt that you'll >>>>see that after the first time you touch the key. If you _do_ get the car >>>>started it'll just be an opportunity for you daughter to get stranded >>>>some place. >>> >>>It started OK after about 6 hours at 1.2 amps, started vigorously >>>after charging all night. My wife's car was zero-volts dead a couple >>>months ago, got rebooted from the DSL wall-wart, and it's fine. >>>Lead-acids will sulphate and lose capacity if they sit dead for a long >>>time. >>> >>>> >>>>One new battery is cheaper than one tow truck ride. Do the math. >>> >>>Our insurance covers the truck ride. >> >>It's the brat's vehicle, IIRC. I wouldn't beg *any* trouble for a >>woman's vehicle. ...for more reasons that I can count. The brat's, >>never. > >She left the Echo - her high school car - in our garage because all >she wants to drive now is her Jeep Rubicon. Gotta get her to sell the >Echo so we can have our garage back. > >http://www.rubicon-trail.com/ Ah, I misunderstood incorrectly. I thought it was the car she drives that had the bum battery. >But if her car battery did go dead, she wouldn't have any trouble >getting a jump start. Were she my daughter, that's exactly what I'd be worrying about.
From: Jim Thompson on 28 Sep 2009 23:20 On Mon, 28 Sep 2009 21:43:42 -0500, krw <krw(a)att.bizzzzzzzzzzz> wrote: >On Mon, 28 Sep 2009 17:39:24 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Mon, 28 Sep 2009 19:28:39 -0500, krw <krw(a)att.bizzzzzzzzzzz> wrote: >> >>>On Mon, 28 Sep 2009 09:06:34 -0700, John Larkin >>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Mon, 28 Sep 2009 09:04:17 -0500, Tim Wescott <tim(a)seemywebsite.com> >>>>wrote: >>>> >>>>>On Sun, 27 Sep 2009 21:16:46 -0700, John Larkin wrote: >>>>> >>>>>> Last time a car went dead in the garage, my wife's Fit, I hacked up a >>>>>> charger from an old DSL wall-wart and a sabre saw as a series current >>>>>> limiter. The garage geometry makes it essentially impossible for us to >>>>>> push a car uphill to the street to jump it. Now The Brat left her Echo >>>>>> in the garege for a month or so and it went dead, too. So I figure it's >>>>>> time to buy a real charger. Went to Kragen Auto Parts and bought two >>>>>> (one for here, one for Truckee) chargers. They are all "smart chargers", >>>>>> namely switchers with electronics, these days. >>>>>> >>>>>> The battery is really dead, 1.8 volts. The first charger hums and >>>>>> outputs nothing. Tried the next one: it hummed for maybe 3 seconds then >>>>>> sparked and smoked inside. >>>>>> >>>>>> Went back to Kragen and traded up, two better chargers. Neither >>>>>> charges... no current, battery steady at 1.8 volts. Both have their >>>>>> "charging" LEDs off and "charge complete" LEDs lit. >>>>>> >>>>>> Back to Kragen, 3rd time, got all my money back. Passed by Bob Pease's >>>>>> place all three trips, same collection of rusty VWs everywhere. >>>>>> >>>>>> A charger that puts zero amps into a dead battery does that by design, >>>>>> and there's only one reason to do that: to convince people they need a >>>>>> new battery. Kragen's sales pitch was exactly along those lines; "Tt >>>>>> won't charge, so all the cells are shorted." >>>>>> >>>>>> So I went to work and nabbed a cute little Lascar bench power supply. It >>>>>> current limits at 1.2 amps, so I just cranked it up. The battery went >>>>>> instantly to 16.5 volts, then settled down to 12 or so in a few minutes, >>>>>> and is creeping back up. >>>>>> >>>>>> Interesting. >>>>>> >>>>>> So I guess I'll buy a couple of 3 amp or so lab supplies, with nice volt >>>>>> and amp meters, instead of battery chargers. They're handier to have >>>>>> around anyhow, cost about the same as a "good" charger, and aren't booby >>>>>> trapped. >>>>>> >>>>>> What Kragen is doing is fraud. >>>>>> >>>>>> John >>>>> >>>>>I've never had a battery come back from being that dead, and I've had >>>>>numerous chances to try it (I'm stubborn that way). You'll be lucky to >>>>>see 12V out of it with the charger disconnected, and I doubt that you'll >>>>>see that after the first time you touch the key. If you _do_ get the car >>>>>started it'll just be an opportunity for you daughter to get stranded >>>>>some place. >>>> >>>>It started OK after about 6 hours at 1.2 amps, started vigorously >>>>after charging all night. My wife's car was zero-volts dead a couple >>>>months ago, got rebooted from the DSL wall-wart, and it's fine. >>>>Lead-acids will sulphate and lose capacity if they sit dead for a long >>>>time. >>>> >>>>> >>>>>One new battery is cheaper than one tow truck ride. Do the math. >>>> >>>>Our insurance covers the truck ride. >>> >>>It's the brat's vehicle, IIRC. I wouldn't beg *any* trouble for a >>>woman's vehicle. ...for more reasons that I can count. The brat's, >>>never. >> >>She left the Echo - her high school car - in our garage because all >>she wants to drive now is her Jeep Rubicon. Gotta get her to sell the >>Echo so we can have our garage back. >> >>http://www.rubicon-trail.com/ > >Ah, I misunderstood incorrectly. I thought it was the car she drives >that had the bum battery. > >>But if her car battery did go dead, she wouldn't have any trouble >>getting a jump start. > >Were she my daughter, that's exactly what I'd be worrying about. That's why I went in the Nissan dealership with cash in hand, and asked my daughters, "Which color?" ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Coming soon to the elementary school in your neighborhood... I pledge allegiance to Dear Leader Barack Hussein Obama and to the community organization for which he stands: one nation under ACORN, unchallengeable, with wealth redistribution and climate change for all.
From: David Lesher on 28 Sep 2009 23:34 John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> writes: >I have plenty of other stuff to design. I did hack a charger from an >old DSL wall wart and a sabre saw; isn't that enough? >John Hell no; it MUST use duct tape or it does not count. -- A host is a host from coast to coast.................wb8foz(a)nrk.com & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433
From: news on 29 Sep 2009 03:46 In article <ok02c551ujbtjfrhi03c6seqies88jshkd(a)4ax.com>, jjlarkin(a)highNOTlandTHIStechnologyPART.com says... [snip tale of poorly engineered battery charger] > > I have an Agilent DVM that has a serious hardware problem that they > obviously hid with firmware. > Details? Name and shame! We were looking for a 6.5 digit DMM at about the time you posted your troubles with the Keithley. So we struck them off the list and bought a 34410A instead. It's not one of these is it? > > > > >It's nice to warn people, but building something that refuses to do the > >job it's built for is poor engineering. (Of course our current plague > >of tort lawyers is partly responsible, but only partly.) > > The charger has no warnings anywhere. The "charged" LED comes on. The > implication to common folk is that a discharged battery can't be > charged and has to be replaced. That's the only kind that Kragen seems > to sell. > > John > >
From: Jan Panteltje on 29 Sep 2009 07:22
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