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pete <acdfg@none.net>: Jun 28 07:14AM -0400 I had a recent power outage that lasted for 3 days. Not having a generator on hand, I decided to try using what I did have for short term power purposes. The items consisted of the car, 500 watt inverter, and I had an extra car battery available.   I hooked up the inverter directly to the car battery in the car. With the car running, I was able to run the 46" LCD TV, and a couple of CFL lights which was all I really needed to do. However, I ran into some problems. If the car wasn't running the entire time, the items connected to the inverter would start flickering on and off after a period of time. If off of the car battery inside the car, this might be within an hour, but with the separate battery, maybe 10 minutes unless it was coupled to the car battery in the car with the car running.   All in all, I was disappointed. I'm wondering why the items wouldn't operate correctly unless the car engine was running. There certainly wasn't a lot of wattage being drawn.... the TV uses like 100 watts with the lights maybe 10 watts each, and there were 2. I had hoped to just use the battery in the car to occasionally "jump" and charge the separate battery when it got too low, but never got to that point as the attached items would start flicking on and off.   I see portable power packs with internal battery and inverter at places like Walmart. The inverter is usually 400 watts or so, so I know this method should have worked. Any ideas as to why my set up didn't work well would be welcomed. If it had worked this time, I had planned on maybe a 1000 watt inverter at some point which I had hoped maybe if this happened in the future to be able to run the house refrigerator from the inverter/ car battery set up, but not if I have to have the car running the entire time.   Thanks for your help.   Pete

N_Cook <diverse@tcp.co.uk>: Jun 28 01:15PM +0100 On 28/06/2015 12:14, pete wrote: > the entire time.   > Thanks for your help.   > Pete   So what was the DC over the battery in the 4 situations, battery idle, battery being charged, battery powering inverter only, battery and charger powering inverter ?

Aleksandar Kuktin <akuktin@gmail.com>: Jun 28 02:12PM On Sun, 28 Jun 2015 07:14:43 -0400, pete wrote:   > period of time. If off of the car battery inside the car, this might be > within an hour, but with the separate battery, maybe 10 minutes unless > it was coupled to the car battery in the car with the car running.   Maybe you overdrew the battery?   A normal car battery has a power of maybe 5kW. It's normally run for a few seconds which means it normally supplies, let's say, 10kJ of energy. It's designed to release a few percents of the total energy stored within itself. Lets say 2%. So a fully charged battery contains about 500kJ of energy, however only a small percentage of that is repeatedly recoverable. If we say a car battery can be discharged to 10% repeatedly, that gives us 50kJ to work with. If we draw that energy at a rate of 200W, it will expire in 500 seconds, which is 8.33 minutes and close to your measurement of 10 minutes.   The critical question is at what internal charge level does the battery start dying? If the voltage at the terminals starts dying when the charge drops to 90%, that explains the performance of the extra battery. If the charge has to drop to 30% before the battery starts to fail, that explains the behavior of the in-the-car battery.   Obviously, my calculations assume undamaged batteries. If the batteries were heavily used and were overdiven previously, that would lower the total amount of energy present in them and ipso facto lower the amount of recoverable energy.   > I see portable power packs with internal battery and inverter at places > like Walmart. The inverter is usually 400 watts or so, so I know this > method should have worked.   100% certain that the secret is in the battery.   For this scheme to work assuming lead-acid batteries, you want a battery that can be severely discharged, a so-called "deep cycle battery". These come in many varieties so shop around if you're interested. You can also make it work with NiCd batteries. Some have also suggested NiFe batteries that you can supposedly build yourself.

Jeroni Paul <JERONI.PAUL@terra.es>: Jun 27 02:38PM -0700 N_Cook wrote: > that about 07:00 but on returning in the evening the erroneous clock had > reset itself. How to predict when this error will reoccur? any > amelioration, plenty of LCD contrast so presumably the batteries are ok?   I live in a fringe reception area for the german time signal at 77.5kHz and have many clocks that use this signal but because a marginal reception they do not always sync. The curious thing about this is every night I have a different set of clocks sync, they seem to decide at random when the signal was good enough.   The oldest one is 13 years old and is an alarm clock I check daily, in these years I have had it three times take an incorrect time/date probably from interference. It either takes the right time or does not sync, three times in 13 years seems not bad for the simple parity bit protection the protocol uses.   I think, however, it is somewhat dangerous to have the clocks sync at night *after* you have checked they are set correctly, so if bad reception sets wrong data they will fail to wake you up at the right time.

thekmanrocks@gmail.com: Jun 27 07:26PM -0700 Jeroni Paul wrote: "The oldest one is 13 years old and is an alarm clock I check daily, in these years I have had it three times take an incorrect time/date probably from interference. It either takes the right time or does not sync, three times in 13 years seems not bad for the simple parity bit protection the protocol uses.   I think, however, it is somewhat dangerous to have the clocks sync at night *after* you have checked they are set correctly, so if bad reception sets wrong data they will fail to wake you up at the right time. "     Enough reasons for me not to use the freakin' things...   I've got the best time sync source of all, courtesy the NIST and WWVB! ;)

Jeff Liebermann <jeffl@cruzio.com>: Jun 27 07:56PM -0700 On Sat, 27 Jun 2015 14:38:33 -0700 (PDT), Jeroni Paul   >I live in a fringe reception area for the german time >signal at 77.5kHz   Spain? According the coverage map at: <http://www.ptb.de/cms/en/ptb/fachabteilungen/abt4/fb-44/ag-442/dissemination-of-legal-time/dcf77/reach-of-dcf77.html> Yes, the signal is probably not very strong and you're in the skywave only region.   >and have many clocks that use this signal but because >a marginal reception they do not always sync.   That sounds like the older amplitude modulated system. DCF77 also transmits a phase modulated signal, <https://en.wikipedia.org/wiki/DCF77#Phase_modulation> which works better for weak signal due to better processing gain. I'm in the USA and have not tried it with over-the-air DCF77, but have played with simulators and with WWVB, which also has a phase modulated BPSK signal. The problem is that the technology seems to be patented and chips are not forthcoming. Also, the addition of BPSK modulation caused some old WWVB receiver chips to fail. No clue what the situation was with DCF77 but it might be worth checking.   >The curious thing about this is every night I have a different set >of clocks sync, they seem to decide at random when the signal was >good enough.   Kinda sounds like you're getting some local interference. It doesn't take much computah or switcher noise to trash the signal, especially when it's weak in the first place. If your devices have a loopstick for an antenna, they are directional, with the strongest signal perpendicular to the loopstick. I was having random updates until I moved my WWVB clock away from several switching power supplies.   >probably from interference. It either takes the right time or does >not sync, three times in 13 years seems not bad for the simple parity >bit protection the protocol uses.   It's a bit more than just the parity bit. Some chips require that the correct time be received successfully more than once before it will sync. This is a function of the chip design.   >at night *after* you have checked they are set correctly, so if >bad reception sets wrong data they will fail to wake you up at >the right time.   Sorry, but you don't have a choice as to what time to sync. Propagation at VLF frequencies works best after midnight in the USA. I think it's the same for a north-south path, but I'm not sure. Note the increases in coverage area after midnight for WWVB: <http://tf.nist.gov/stations/wwvbcoverage.htm> <http://www.febo.com/time-freq/wwvb/sig-strength/> I couldn't find something similar for DCF77.           -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558

Michael Black <et472@ncf.ca>: Jun 27 11:37PM -0400

N_Cook <diverse@tcp.co.uk>: Jun 28 01:06PM +0100 On 27/06/2015 22:38, Jeroni Paul wrote:   > I live in a fringe reception area for the german time signal at 77.5kHz and have many clocks that use this signal but because a marginal reception they do not always sync. The curious thing about this is every night I have a different set of clocks sync, they seem to decide at random when the signal was good enough.   > The oldest one is 13 years old and is an alarm clock I check daily, in these years I have had it three times take an incorrect time/date probably from interference. It either takes the right time or does not sync, three times in 13 years seems not bad for the simple parity bit protection the protocol uses.   > I think, however, it is somewhat dangerous to have the clocks sync at night *after* you have checked they are set correctly, so if bad reception sets wrong data they will fail to wake you up at the right time.   Have you had the situation of the displayed time jumping by an hour or two? As an alarm clock, losing synch and drifting a second or two , to a background quartz crystal clock, is no great problem

Peabody <waybackNO584SPAM44@yahoo.com>: Jun 27 12:59PM -0500 I have a feature phone that's several years old, but still works fine. But the battery is on its last legs, and I'm having a problem replacing it. The battery is an Alcatel CAB3120000C1, which is 3.7V, 850 mah.   These batteries are all over Ebay, but a seller I contacted confirmed that the battery was discontinued several years ago, so the date code on all these OEM batteries is several years old, and they don't do very well anymore. The most recent one I've been able to find is the one I have, which is 2013. Most are 2010-2012. One seller offers non-OEM replacements, but didn't respond to my question about the age of his batteries.   I wondered if it might be possible to buy a *new* replacment cell, and put that into the battery, preserving all of the protection circuitry in the original. The battery is very thin - 4mm - and I don't know where to find a replacement cell that would work. The overall size is 40 x 50 x 4 mm.   I would hate to have to buy a new phone just because of the battery issue. Can anyone suggest a solution to this problem?

"jfeng@my-deja.com" <jfeng@my-deja.com>: Jun 27 01:25PM -0700 I loooked on eBay. They seem to be going for $3-$6, including shipping. If it were me and I was this sentimental about the old phon, I would be willing to risk that much money. When I went to eBay and bought a replacement battery for my old phone, I certainly did not agonize over these boogeyman concerns, and the new battery definitely worked better than the one it replaced (I did not bother to test it to make sure it had the full maH capacity of the OEM battery).   If the new battery cost $50 or more, I would probably have a different attitude.

Sjouke Burry <burrynulnulfour@ppllaanneett.nnll>: Jun 27 11:29PM +0200 On 27.06.15 19:59, Peabody wrote: > replacement cell that would work. The overall size is 40 x 50 x 4 mm.   > I would hate to have to buy a new phone just because of the battery issue. > Can anyone suggest a solution to this problem?   Google around in your country, for a battery rebuilt company. They open up the battery pack, and replace the old cells with new.

mike <ham789@netzero.net>: Jun 28 04:14AM -0700 On 6/27/2015 10:59 AM, Peabody wrote: > replacement cell that would work. The overall size is 40 x 50 x 4 mm.   > I would hate to have to buy a new phone just because of the battery issue. > Can anyone suggest a solution to this problem?   Replacing the cell is trivial. Find a battery the same size and swap the cell. Usually, all it takes is to peel off the plastic tape and unsolder the two tabs. Laptop batteries often shut down when you disconnect the cells and won't recover. Never had that problem with a cellphone/PDA type battery.

N_Cook <diverse@tcp.co.uk>: Jun 28 08:08AM +0100 On 29/03/2015 11:06, N_Cook wrote: > light, only illumination is if you switch on the internal lamp. > Just had summertime clocks change here, could not be easier to adjust > this clock, just turn the small knob on the side 6 turns forward or back.   From a horologist at Combe Mill centre http://www.combemill.org/ the separation of winding and escapement sections (1/6 of a turn business), for better timing, is called a remontoire movement

Phil Allison <pallison49@gmail.com>: Jun 27 05:58PM -0700 Ian Malcolm wrote: > The charger should be rated for the maximum total AH capacity to be > connected to it and needs to be set for SLA batterys and to have a > constant float mode.   ** Most Gel/SLA chargers have affixed maximum voltage between 13.8 and 14 volts which IS the float mode. A fully charged 6 cell battery will draw only a trickle of current at this voltage.   They also normally have a "current limit" feature that operates when a partly or fully discharged battery is connected, which ought not apply in the OP's case.     > A 12V 10W bulb in series with each battery will prevent excessive current > flow allowing discharged batteries to be recharged safely and also > provides visual indication of any shorts.     ** With bulbs like that fitted, a SLA charger rated at say 3 or 4 amps would do fine with 6 x 7AH batteries at once in the OP's situation.       .... Phil

"Michael A. Terrell" <mike.terrell@earthlink.net>: Jun 27 09:25PM -0400 > On Friday, June 26, 2015 at 12:08:38 PM UTC-4, captainvi...@gmail.com wrote: > > I have a customer who wants to buy twelve 12.0 volt 8.0 AH gel cells from me. He uses these in his fire alarm panels and wants to keep a quantity in stock for when one of these panels goes down for battery failure. I've explained to him about the need for trickle charging these while they're sitting on the shelf, and rather than sell him 12 individual trickle chargers I was wondering if anyone knows of a cost effective series charger whereby I could put perhaps 6 in series and charge them all at the same time. I would probably not want to go above 6 and I would not do this with anything other than new batteries all of the same type and rating. Thanks, Lenny   > I can imagine haw this might be a concern in high current charging, but how important in float or trickle applications is it that all batteries be fed with the same series resistance, such as equal length leads from the charging source? Lenny       What happens when he uses one out of that string? The next battery will need more charging current. What happens when he has less than six batteries in stock? Why complicate things?

"Rheilly Phoull" <rheilly@bigslong.com>: Jun 28 10:53AM +0800 "Michael A. Terrell" wrote in message news:8sGdnejLpuOQ0BLInZ2dnUU7-I-dnZ2d@earthlink.com...     > how important in float or trickle applications is it that all batteries be > fed with the same series resistance, such as equal length leads from the > charging source? Lenny       What happens when he uses one out of that string? The next battery will need more charging current. What happens when he has less than six batteries in stock? Why complicate things?   As I recall in a past lifetime, Vesta had a display rack that held a collection of 2 - 6 or 12volt batteries. It came with a fixed current trickle charger for all the batteries to be connected in series. It would seem to me the matter is being made into a mountain rather than a hillock, the answer would seem to me to be a matter of education since both methods would work in the right hands.

Phil Allison <pallison49@gmail.com>: Jun 27 11:07PM -0700 Rheilly Phoull wrote:   > rather than a hillock, the answer would seem to me to be a > matter of education since both methods would work in the > right hands.   ** Sure, it's possible to make the 6 x 12V Gel batteries in series idea work. But you would have to design and build a one off charger rather than use a cheap, off the shelf unit and a few bulbs.   Plus outputting over 84V DC is getting a bit hazardous too.     ... Phil

Pat <pat@nospam.us>: Jun 27 01:39PM -0400 On Sat, 27 Jun 2015 15:51:32 +0000 (UTC), "tb" >be some sort of power supply with power cables that would go to the >fans, the hard drive, the graphics card,etc.; just like in a desktop >computer. I'm not much of a techie... AC/DC converter is another name for a power supply. As someone else said, this particular power supply takes 120 VAC in and provides 18.5 or 19 volts DC out. Insiode the laptop, that 19 volts gets regulated by other components on the motherboard and reduced to the various voltages needed by the chips (eg, 5 volts, 3.3 volts, etc). If those circuits on the motherboard have failed, it is likely you need to replace the motherboard. It may or may not be cost effective to do.

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