Home UPS powered by car battery in Electronics http://www.dslreports.com/forum/r19119779 en Mon, 09 Nov 2009 01:34:48 EDT Mon, 09 Nov 2009 01:34:48 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20213389 ericrazar : I would look at the circuit board again on both sides to be sure you didn't vaporize the copper traces going to the battery wires or some other hidden fuse. It sounds like you did the wiring correctly otherwise based on the charging voltage measured before/after the parallel hook up. Of course if you had a short occur due to wire heating and terminals moving and shorting that could have happened too I guess. if you read earlier post what i did with my apc 1000 setup with the marine batteries i used heavy wire up to the batteries and transition down to the 8-10 gage wires inside the unit with ring terminals. I read you have an external rear connector so that is convenient but should still use heavy gage wire and transition to a wire size that the connector uses. ]]> http://www.dslreports.com/forum/remark,20213389 Sun, 23 Mar 2008 17:29:34 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20046925 aurgathor :
said by migr See Profile :

i was wondering if there was a way to change the nominal voltage it expects to see from the batteries.
Find the place where it senses the voltage, and "lift up" that sensor connection somehow, either putting in a small 1.2V - 1.5V battery in serial, or through some resistors and a higher voltage external source. I'd try a small battery first.]]> http://www.dslreports.com/forum/remark,20046925 Fri, 22 Feb 2008 23:52:11 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20044766 SparkChaser : I've been unable to find any info on the Mecer unit except that one page. So, there is little to go on. They claim everything is protected. I guess you found one vulnerable point.

What kind of load did you have on the unit at the time of the switch to batteries? What gage wire did you use to connect them? This thing can draw quite a bit of current.

I'm not a fan of parallel batteries but it's done all the time, so, what do I know. It's certainly better if you use all of the same type and capacity to minimize any circulating currents.

You may have just done something that the circuit was not prepared for. Anytime you go beyond the supplied part you run that risk.


--

"Facts do not cease to exist because they are ignored." - Aldous Huxley
]]> http://www.dslreports.com/forum/remark,20044766 Fri, 22 Feb 2008 16:47:29 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20042156 zoltan48 : Yes I measured the voltage when I opened
it, it was 39 Volts with disregard-able low
load. That should be normal for one battery
is +/- 13V fully charged. Before I connected
the auxiliary battery pack, I measured it as
well, it was 40V. After I connected the two battery packs, I measured It again, and it was somewhere between 39V and 40V, which is expected. This should make that the auxiliary battery pack charge the internal battery pack with one Volt difference. Everything was
connected and was working well while it was
on AC, which makes me dare to say it roles
out wires crossing(If I understand it right,
wires shorting). Except if wires could
connect that it created a higher voltage,
which I doubt, because I used proper
insulated crimping connectors. I opened it
afterwards, and there was no sign of
something that shorted. It did smell like
something that shorted, my guess was that it
could be the relays, maybe they sparked
inside, making a bright enough light, being
visible from outside the relay and the Ups
box itself. There is three 40A fuses, on the UPS board which did not fuse. It was the first thing I checked.]]> http://www.dslreports.com/forum/remark,20042156 Fri, 22 Feb 2008 09:37:53 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041981 CajunWon : I'm no EE
3 issues come to mind:
1)a wire became crossed.
2)the auxiliary battery pack was connected in series with the internal battery pack, providing more than the rated volts.
3)not reading the mfg information, perhaps it requires less than 36v to begin with. Did you measure the volts supplied by the oem battery bank?]]> http://www.dslreports.com/forum/remark,20041981 Fri, 22 Feb 2008 08:57:17 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041543 zoltan48 : "ME-2000RBK, ME-3000RBK: 8 batteries" and further down "ME-2000-BK: 12V/9 Ah x 2pcs" which is incorrect for mine has 3 batteries. Yes it worked fine with its own batteries.]]> http://www.dslreports.com/forum/remark,20041543 Fri, 22 Feb 2008 06:00:15 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041535 SparkChaser :
said by zoltan48 See Profile :

Yes I bought the "ME-2000-BK (2000VA): 1080W"

I did not mention that I did not had any load on the UPS when I tripped the AC, don't know if that could have made the difference.
The reason I asked was, for the 2000 it says 8 batteries. It doesn't say what configuration.

I never heard of Mecer. It appears to be a SA company. I wonder if these are re-branded from another manufacturer. There isn't too much info on the Mecer site. Did you operate it without the second bank before it went up on smoke?
--

"Facts do not cease to exist because they are ignored." - Aldous Huxley
]]> http://www.dslreports.com/forum/remark,20041535 Fri, 22 Feb 2008 05:52:05 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041525 zoltan48 : Yes I bought the "ME-2000-BK (2000VA): 1080W"

I did not mention that I did not had any load on the UPS when I tripped the AC, don't know if that could have made the difference.]]> http://www.dslreports.com/forum/remark,20041525 Fri, 22 Feb 2008 05:43:24 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041519 SparkChaser :
Which one did you buy, one of these? »www.mecer.co.za/content/blogcategory/24/90/]]> http://www.dslreports.com/forum/remark,20041519 Fri, 22 Feb 2008 05:35:07 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,20041417 zoltan48 : I broke my new UPS. I converted a couple of old 400VA UPS's to 96Ah deep cycle batteries giving more that 6 hours running one PC. Here in South Africa we are having serious "power shedding" problems. Having our power off for more than 2 hours daily. This lead me to buy a MECER 2000VA UPS. Opening it I realized I will need 3 batteries in series, giving 36V. I hooked up 3 96Ah batteries in series. I mounted a socket on the outside of the UPS so that I can disconnect the extra battery bank, using the UPS separately. This means it was two different capacity 36V battery banks in parallel, but still supplying 36V. I tested it, It started up with the AC connected, then I tripped the AC. There was a loud noise, sounded like arcing and I could see sparks through the vent. I can't think what went wrong. Please, any advice would be appreciated.]]> http://www.dslreports.com/forum/remark,20041417 Fri, 22 Feb 2008 03:42:33 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19811823 anon : APCFiX Home page: »apc-fix.com/page.php?al=apcfix]]> http://www.dslreports.com/forum/remark,19811823 Wed, 16 Jan 2008 09:27:12 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19797550 ericrazar : the real genius is the guy who wrote the apcfix.exe . I am just an observant engineer lucky enough to find it. I found a tech at APC website say they ship out a "hardware key" that goes on the rs232 port to reprogram the unit to the A0 constant. The apcfix guy did it without all that. Also note that other size model smart ups that the default battery constant is different but the apcfix appears to know each of the right values.

Update:
It appears besides the apcfix there is a way to do it though hyperterm. Check warning in link. You need to know what the default value is for your particular model APC UPS.

»www.rm.com/Support/TechnicalArti···rrer=rss]]> http://www.dslreports.com/forum/remark,19797550 Mon, 14 Jan 2008 11:06:29 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19796457 migr : that was it m8, you are a genius. that apcfix worked out perfectly. now with 44% load it said 570min run time, so 9 hrs. i am reducing that to around 6 external battery packs now to reduce the run time, it was on 8 for that 570min run time. i think around 5-6 hrs is more than enough, when it gets that low it will shut down the server which is what i wanted.

I cant thank you enough for that usfull hint m8. u solved my problems anyways

EDIT: i ended up reducing it to 4 extrrnal batteries giving me a total of 6.2hrs estimated run time
more than adiquit, in most power cuts it will just remain running till the power comes back on, infact, i cant remember ever having a power cut last longer than that.

Thanx again m8]]> http://www.dslreports.com/forum/remark,19796457 Mon, 14 Jan 2008 05:06:24 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19793202 ericrazar : PUBLIC :
MY SU3000 is the 5 U rack mount type with 4 x 20 amp hr gel cells. I would get only 10-15 minutes with a less than 500 watt load with old or newer OEM style gel cells. My 2200 with the same new batteries at work would last ~25 min with a 800W load. See the discrepancy? Now that I realize the battery constant issue I expect it should be a non issue once I fix the constant back to factory. At the time I put the unit aside thinking it was defective in some way. AS you see from all my earlier posts the issue is the APC UPS's use a coulomb counter feature that measures the actual amp/hours that flowed to and from the battery to determine minutes remaining. This is just like the battery circuit in a laptop. The battery terminal voltage is only part of the story. What actually happens is as the battery ages and it get discharged during an outage or during a "cal" it modifies that battery constant as the usable amphr capacity goes down. What is bad is APC doesn't seem to have a convenient way to reset that to factory other than what I found. My APC 1000 with the wet cells give excellent run time (12 hrs at 160watts) if the external batteries modules and battery constant are set correctly. While I agree that the wet flooded cells don't quite have the low internal impedance and surface charge voltage the GEL type have it is obvious the real problems are the constants and not the chemistry.]]> http://www.dslreports.com/forum/remark,19793202 Sun, 13 Jan 2008 16:37:54 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19793035 public :
said by ericrazar See Profile :

It is good this issue came up because I have a somewhat similar problem with a apc3000 that has short run time too even with modest loads and good batteries. You made me go back and look harder for a better solution.
SU3000 should never be used with the internal microscopic batteries at heavy load unless you like seeing flames.

Wet cell batteries used by telcos have lower terminal voltage than the sealed agm types for which the ups is preset. Hence some of your problems.

If you use apc ups's get one of the smart slot management cards and do not waste time with serial ports or terminal emulators.]]> http://www.dslreports.com/forum/remark,19793035 Sun, 13 Jan 2008 16:02:45 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19792579 ericrazar : ok migr. I just discovered something about one of my SU1000 that made one read much lower minute run time than the other. It has to do with the battery constant. With hyperterm after you type Y and get SM back type 0 (zero not letter O). You should get back A0 if you dont then the battery constant is screwed up. On one of my units it read 55 which gave me 20 min estimated run time on the other (A0 one) it gave 45 min. This was when both had 000 external battery packs. Raising the battery pack to 001 for the 55 unit made it work to 45 min also. I suspect your constant must be really low so that adding battery packs in hyperterm doesnt help. I also found you cant readjust the battery constant it in hyperterm. I did find you can fix it with APCFIX.exe .

»apc-fix.com/page.php?id=22

Go to the download link on that page bottom and extract the RAR file. Shut down your hyperterm or powerchute software. Run APCFIX and choose com port. Go to options in upper left hand corner and click both the battery constant auto fix and the hex code detection on. I had to close the program then and restart it then pick com port again then it automatically would fix my "0" battery constant from 55 to A0. Then when you add battery packs (with hyperterm) it should work right again and give you proper minutes with your external batteries and with powerchute running. It is good this issue came up because I have a somewhat similar problem with a apc3000 that has short run time too even with modest loads and good batteries. You made me go back and look harder for a better solution. :) BTW For a 24 volt system each external apc pack equals ~36 amp hr capacity. So 5 packs equals ~180 amp hr and 10 packs ~360amphr This would help you to get the run time minutes roughly "right" when equating to your external battery setup. In your case I would adjust the battery count till your estimated run minutes equals 480 or more or so at the 44% load. It seems wet cells require you to "lie" to the UPS and say you have more batteries than actaul amphour amount. I ended up with 5 external batt setting myself for my 125amp marine batt pack.

The

www.apcupsd.com

website PDF manual has most of the info on the codes.

GOOD luck !!!! :) :) :)]]> http://www.dslreports.com/forum/remark,19792579 Sun, 13 Jan 2008 14:27:37 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19790775 migr : the unit is 9 years old, as are the origional batteries that i took out of it so those bats are no good for anything. the cables from the batteries to the unit are top notch, its the same cabling we use to run -48vdc perminently in telephone exchanges all over australia. this cable is capable of carrying a constaint -48v @90a and the terminations are the same that i use in the exchange also. the problem is with the unit its self. i updated the unit so that it now believes new batteries were installed a couple of days ago instead of 9 years ago likt it was when i 1st aquired the unit. i think its a lost cause. atm i am running it in dumb mode. if the power goes down it will hold my rack for 8 hours and thats all that matters, but it would be nice to be able to monitor the battery status via the serial port the way it was intended.]]> http://www.dslreports.com/forum/remark,19790775 Sun, 13 Jan 2008 02:59:07 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19789388 ericrazar : ok migr. I just read you response and it seems your UPS has an issue. Is the unit fairly new model? The apc smart UPS ones I used were built in 1999 and another in 2000. The only other thing I would ask is if you had the original dual 12v 12amp hour batteries in the unit would it work correctly at both low and high loads. I also had a newer apc 1500 model used the the DUAL 125 amp hour batteries for a test setup at my job to hold an environmental chamber up during a possible power outage. The chamber in heat mode would cycle up to 6 amps @120 for several seconds each minute and 1 amp the rest of the time. I ran a check with that setup for almost an hour before I know about the reprogramming advantage with hyperterm. So it sounds like your UPS has an issue unless it works correctly with the original batteries or you have a defect in your harness hookup that causes too much drop at higher loads making the ups think the battery is dead. ]]> http://www.dslreports.com/forum/remark,19789388 Sat, 12 Jan 2008 21:05:27 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19787391 SmokChsr : In that case.. It looks like the UPS battery sense circuit has a problem. ]]> http://www.dslreports.com/forum/remark,19787391 Sat, 12 Jan 2008 14:18:39 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19783777 migr : no i am running 24v m8, i have 2 x banks of 2 batteries, so in total i have 4 batteries so i have 2 x bats of the same sort making up 24v then i have another 2 x 12v bats making up another 24v then i parallel the 2 banks of 24v. the origional bats were just the same but on a smaller scale and without the 2nd bank.
The unit was designed to run with 24v and thats what i have provided it with but just with larger capasity batteries.]]> http://www.dslreports.com/forum/remark,19783777 Fri, 11 Jan 2008 19:47:48 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19783733 SmokChsr :
said by migr See Profile :

i ran the calibration but it gets to 25% bat in secconds so it doesnt really get a chance. it just believes they are dead when they are not
In this case I would have to soy something is flaky with the UPS. The only judge of battery that the UPS has is normally voltage. With this new information I would tend to think that the threshold voltage is set improperly. I don't suppose there is any way that the UPS was actually designed to run on 24V using 2 batteries in series is there and now you are running 12V? That of course would tend to try to overcharge the battery. ]]> http://www.dslreports.com/forum/remark,19783733 Fri, 11 Jan 2008 19:39:21 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19779569 migr : sorry m8, i wasnt having a go at you. just trying to clarify the sizes so others didnt think i was useing tiny wire. my apoligies if you thought otherwise]]> http://www.dslreports.com/forum/remark,19779569 Fri, 11 Jan 2008 06:26:17 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19779564 migr : ok 1st point, how long does it take to get to 0 min, about 30 sec and it doesnt make a difference weather it thinks it has no external batteries or 12 external batteries.

i ran the calibration but it gets to 25% bat in secconds so it doesnt really get a chance. it just believes they are dead when they are not

the batteries, well i am running 2 banks of 12v batteries. the 1st bank is a set of 2 12v gel cell deep cycle batteries designed to hold up a local pay tv network for hours. they are usually mounted up power polls and linked to an inverter for years at a time. the seccond set is a set of 2 x 12v truck batteries. these are absolutetely huge. not really designed for deep cycle but have like 175 amp hours so will certainly help the up time and are tested to be fine.]]> http://www.dslreports.com/forum/remark,19779564 Fri, 11 Jan 2008 06:24:42 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19779501 ericrazar : When you tried running with the server you said the estimated minutes goes to 0. but you also said that this setup runs the equipment for 8 hrs on 44% load. How long does it take to go to 0 estimated minutes? Right away or after several hours? To help you out I can share what happened to me when i set my SU1000 to 10 external batteries. At first with 25% load I ran a "cal" the estimated percent left (not minutes) stayed high for several hours. It evenually got to 0% near the 12 hour point before going back to ac power (meaning finish cal).
For you I would suggest trying doing a "cal" with the new battery coding to see if it needs to "learn" the estimated minutes. Another thing you can try is to increase the number of batteries to more than 10. I found programing to 20-30 can make the ups think it has power for thousands of minutes. The number can go as high as 255 i found. I expect it will still go to 0 minutes or 0% battery left when the battery is depleted but should get there only when the battery is really dead. It sounds like your UPS thinks the battery is dead to early for some reason. If your battery voltage is still 24.9 with the 44% load then your battery pack setup is good. mine ran something like that also (12v 125 amp hr. times 2) at the 25% LOAD. what kind of batteries you using? 6volt golf cart batteries? ]]> http://www.dslreports.com/forum/remark,19779501 Fri, 11 Jan 2008 05:15:09 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19748015 SmokChsr :
said by CajunWon See Profile :

Didn't know of this DC/AC Amp multiplier, would be nice to learn more of this aspect through on-line reference. My uneducated thoughts are that (given the same load requirement) there should be no more Amps delivered from a large battery than the oem battery if 6' of 14ga wire introduces negligible line loss.
Yes the Current draw would be the same on either battery. Not having looked up this particular UPS, normally the OEM will use very short leads to the battery to minimize the line loss. When connecting longer leads to an external battery then you would want to increase the wire size to compensate for the line loss.
--
Is fire supposed to shoot out of it like that?
]]> http://www.dslreports.com/forum/remark,19748015 Sun, 06 Jan 2008 03:40:15 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19747371 anon :
said by CajunWon See Profile :

6' of 14ga wire introduces negligible line loss.

btw: still using this setup which has worked well through a few power outages and many brown-outs.
Some suggestions.
Do not waste time on the little throw away apc models. Get at least SU1000 or SU1400. These go for about $50-100 on ebay. Then get a web management card for the smart slot so that you can easily monitor what the ups is doing.
The battery thresholds are not user programmable, but you can specify external batteries and extend the run time to hours. SU1400 and bigger have internal fans, but for your load it does not really matter.
User bigger AWG wire, 6' is a long piece. Use fine stranded wire that bends easily.
AGM type batteries are sometimes available at reasonable price, a couple of 12V 100Ah AGM batteries would be a lot safer than wet cells.]]> http://www.dslreports.com/forum/remark,19747371 Sun, 06 Jan 2008 00:18:08 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19744125 SparkChaser :
said by migr See Profile :

no 16mm is more like 8guage, and 5mm is like 10guage
Believe me, I wouldn't have a clue :D I looked here »www.simetric.co.uk/siwire_elect.htm It says between 5 and 6

I use metric for almost everything but wire gauge.]]> http://www.dslreports.com/forum/remark,19744125 Sat, 05 Jan 2008 14:21:39 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19743844 migr : no 16mm is more like 8guage, and 5mm is like 10guage, but i have 16mm all over now so thats not an issue, the stuff i have used is the same stuff i use in telephone exchanges to carry a constaint 63amp load to critical gear. and thats all neg 48vdc so i know its capable of doing the job. so to recap, the cable size as a possable problem has been eliminated and the terminations are also not an issue as they are profesionally done by myself, its my job]]> http://www.dslreports.com/forum/remark,19743844 Sat, 05 Jan 2008 13:26:25 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19743044 SparkChaser :
said by CajunWon See Profile :

Didn't know of this DC/AC Amp multiplier, would be nice to learn more of this aspect through on-line reference.

All SmokChsr See Profile was saying is that the power will at least stay the same. 120V @0.7A= 84 watts, so 84watts/12V =7A that's at 100% efficiency, which it won't be.
--

"Facts do not cease to exist because they are ignored." - Aldous Huxley
]]> http://www.dslreports.com/forum/remark,19743044 Sat, 05 Jan 2008 10:39:16 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19742950 CajunWon :
said by SmokChsr See Profile :

when you are trying to draw 0.7 amps @120V for your laptop that equates to at least 7.0 Amps (if their were no losses {which there are}) at 12V from the battery. In the real world you are probably drawing between 11-15 times the amount of current at 12V than your load at 120V.
Didn't know of this DC/AC Amp multiplier, would be nice to learn more of this aspect through on-line reference. My uneducated thoughts are that (given the same load requirement) there should be no more Amps delivered from a large battery than the oem battery if 6' of 14ga wire introduces negligible line loss.

btw: still using this setup which has worked well through a few power outages and many brown-outs.]]> http://www.dslreports.com/forum/remark,19742950 Sat, 05 Jan 2008 10:21:04 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19742559 SparkChaser : There are 2 threads going here. The first is 3 months old and mentioned 14GA.

The latest by migr See Profile who is using 16mm (about 5GA) and 5 mm (about 10GA) (damn metric wire) :p]]> http://www.dslreports.com/forum/remark,19742559 Sat, 05 Jan 2008 07:31:07 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19742494 SmokChsr : I didn't see a specific response to this particular point, but your #14 wire is too SMALL.. You'll need at a minimum #10, if you have extended the leads from the UPS at all. The Voltage drop on the wire along with the dropping voltage of the battery could very easily account for the early shut off. Also make sure you have good solid connections at every point in the path.

Keep in mind that when you are trying to draw 0.7 amps @120V for your laptop that equates to at least 7.0 Amps (if their were no losses {which there are}) at 12V from the battery. In the real world you are probably drawing between 11-15 times the amount of current at 12V than your load at 120V. ]]> http://www.dslreports.com/forum/remark,19742494 Sat, 05 Jan 2008 06:33:09 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19742167 TheMG : You'd have to look at the UPS circuitry. By luck there might be a potentiometer in there or some resistors that set the reference voltage or sensitivity for the ADC it probably uses to sample the battery voltage for the CPU.

To do that though, you need a good understanding of how these types of circuits work. Otherwise it will mean absolutely nothing to you. Don't just go in there turning random pots if you are not sure.]]> http://www.dslreports.com/forum/remark,19742167 Sat, 05 Jan 2008 02:38:53 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19741598 migr : on your advice i have replaced the cabling from the 1st battery set to the ups with 16mm which is about 5 x the size of the 10g that is internal, i had to leave about 30mm of 10g at the end as it is soldered directly onto the board of the ups and my 16mm will be impossable to solder there. it made no difference sorry m8, any other ideas]]> http://www.dslreports.com/forum/remark,19741598 Fri, 04 Jan 2008 23:57:36 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19741275 migr : im useing 16mmcable from the 2nd set of batteries and 5mm from the 1st set to the ups, the 5mm lengts is only about 500mm long

i would have thought that was more than adiquit being as i have connected it to the existing wireing inside which is 5mm or less?]]> http://www.dslreports.com/forum/remark,19741275 Fri, 04 Jan 2008 22:49:23 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19740279 srr2 : 14Ga wire? That's probably your problem. You should assume currents of 40A to 50A for operating an inverter. I'd use nothing smaller than 8Ga or even heavier depending on how long the leads are.

The currents drawn by inverters can be very high. Milliohms make a difference. In large stationary UPSs with this type of battery it's not unusual to find 0000Ga interconnects.]]> http://www.dslreports.com/forum/remark,19740279 Fri, 04 Jan 2008 19:55:33 EDT Re: Home UPS powered by car battery http://www.dslreports.com/forum/remark,19740137 migr : i was wondering if there was a way to change the nominal voltage it expects to see from the batteries. i have 4 very large batteries. they arent deep cycle but it doesnt matter. if i kill them i just get new ones for free. they are capable of holding my system for up to 8 hours at 44% load on a smart-ups 1001. i added 10 bateries via terminal and that gave a massive time increase when i only have a 9% load on it but as soon as i add my server to it which has 9hdds in it and takes the total load to 44% the estimated run time drops to 0 min. all i can think is to reduce the nominal voltage expected from the batteries because they do drop voltage at the beginning but then levels off at about 24.9 volts and holds there for hours with minor fluctuations. basicly i dont want the ups to shut down my server but i still want to be able to monitor it. anyone know how to change the nominal voltage]]> http://www.dslreports.com/forum/remark,19740137 Fri, 04 Jan 2008 19:33:37 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19386054 mworks : One thing to watch when you extend a ups run time is cooling inside the ups. Some were not designed with cooling to allow for several hours running and will overheat causing failure.

I have an apc ups that I extended the run time on with external batteries , but I placed a 12v dc fan inside the case to help with the heat.]]> http://www.dslreports.com/forum/remark,19386054 Mon, 05 Nov 2007 11:14:58 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19384815 ericrazar : I just finished running a new cal for my apc smartups 1000 VA unit after reprogramming it to think it has 10 external batteries like a 1000xl unit using the hyperterminal example link before. I modified My smartups 1000 to use two external 125 amp hour marine batteries in series where before recoding the unit would have similar run time of only 40 or so minutes even with the large batteries. Now I just got 12 hours of discharge from the setup running a 24% ups load (~160 watts) for 12 hrs. For those of you who have a RS232 com port smartups 1000/1400/2200/3000, you should be able to recode them as well to think they have up to 10 external batteries even though they are not the XL series type UPS's. The only issue is the internal charging circuit for the 1000 va ups will take a long time to recharge an external battery that large. I will look into that issue as well eventually with some external supply to charge the battery set.

»www.apcmedia.com/salestools/ASTE···0_EN.pdf]]> http://www.dslreports.com/forum/remark,19384815 Mon, 05 Nov 2007 03:15:25 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19382367 ericrazar : I found you can reprogram com port smartups with a hyperterminal program to "fool" the ups there are more external batteries. the powerchute software should be able to do it on XL series units but when running regular smartups the power chute shows the external batteries as a "grayed" unchangable field.

»www.apcmedia.com/salestools/ASTE···0_EN.pdf]]> http://www.dslreports.com/forum/remark,19382367 Sun, 04 Nov 2007 17:03:02 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19139671 CajunWon : apcupsd software is interesting, but appearantly not applicable to my setup.

Following a little more research, and to aid others considering this DIY approach to extended UPS protection:

The APC350 cannot know the battery reserve capacity unless using the PowerChutePro software for recalibration. That process would require the APC to fully charge a drained battery -not good for the battery and likely not good for the APC charger. Also the Powerchute software, if running, would perform a shutdown within 3-5 minutes -therefore the software cannot be used with an oversized battery.

Since the APC doesn't know the battery capacity it will begin the 1 second sound warning within 3-5 minutes of power outage, but will continue to output proper current until depletion. If turned Off, the APC will not restart without Utility power present (therefore mine didn't actually fail).

The oversized battery must be externally charged every 6 months and recommended to 'shake' the battery every 6 months.

Use this calculator to estimate reserve time on your chosen battery. Simply input the battery amp our rating and your total equipment hourly usage in amps. »www.smartgauge.co.uk/calcs/peukert3.xls
Amps = Watts/Volts
e.g. 15" monitor 40 Watts; basic desktop PC 85Watts
125 total Watts divided by 120 US Utility Volts = 1 amp/hour

I believe I read the APC350 peaks at 2.5amps but will overheat if sustaining that current.

(again, I'm no EE -just regurgitating what little I've read. YMMV)]]> http://www.dslreports.com/forum/remark,19139671 Tue, 25 Sep 2007 09:21:10 EDT Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19128085 shortckt :
said by CajunWon See Profile :

1- ...The UPS began the 1 second interval alarm very soon after connecting the laptop... I disconnected the laptop and turned-off the UPS to reset and it would not come back on -even after connecting another charged/newer car starting battery...
You tried to restart the UPS with or without AC mains power applied? Some UPS models are designed to allow "cold restart" without AC and others not.
Anyway, I guess we can rule out overheating.
What happens if you just let it run after it begins the "2 minutes remaining" alarm?

2 - Although the powerchute software does control the % discharge b4 beginning orderly shutdown, without the software the UPS is supposed to remain on until complete discharge as calculated by its' cpu. I don't think the software allows changing what the cpu thinks is a minimum charge.
On some models, the remaining battery before the UPS shuts off. This setting is saved in eeprom and UPS obeys it stand-alone, without any outside software control. Useful if UPS is used to power non-computer items.

3- Wonder if there's a way to hard reset the threshold of how low the battery voltage can be within the APC 350.
Don't know for certain, different models have different capabilities, but my guess would be the dead battery threshold is hard coded into the firmware... however there are some trim pots on the logic board.

...I would think the APC is of better quality than my Xantrec inverter.
Sometimes that can be a bad thing. IMO the "smart" devices are sometimes too smart for their own good.
Along those lines, (just thinking out loud here) could the battery control circuit be thrown off by the internal resistance of the battery? Such a large battery must have different electrical characteristics than the original gel cell.

The folks who created APCUPSd have spent considerable time reverse engineering and documenting the APC brand UPS. Per their manual the CS/ES models are treated, for programming purposes, as "smart" devices just like higher end Smart-UPS.

»www.apcupsd.com/
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watchen das blinkenlights]]> http://www.dslreports.com/forum/remark,19128085 Sun, 23 Sep 2007 06:25:15 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19124217 drjim : Not to be picky about your voltmeter, but if you can't really read the difference between "11-14 Volts", it's time to get a better meter!
I have 4 APC units here, both SmartUPS and BackUPS, and they make a big deal about running the calibration routine every time you change the battery, even if you replace it with an identical one.
--
One man's Magic is another man's Engineering.]]> http://www.dslreports.com/forum/remark,19124217 Sat, 22 Sep 2007 12:25:37 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19123521 CajunWon : Thanks again, appreciate your time on my little project.

1- The UPS (and the 14ga wires to my battery) should handle 2.5 amps for ~10 minutes without overheating. Both the UPS and wires remained cool to touch (not that that means a whole lot). I was drawing less than 0.7 amps for the laptop as the only connected device. The UPS began the 1 second interval alarm very soon after connecting the laptop. I disconnected the laptop and turned-off the UPS to reset and it would not come back on -even after connecting another charged/newer car starting battery. Perhaps it would have continued powering if I hadn't shut it down?

2 - Although the powerchute software does control the % discharge b4 beginning orderly shutdown, without the software the UPS is supposed to remain on until complete discharge as calculated by its' cpu. I don't think the software allows changing what the cpu thinks is a minimum charge.

3- Wonder if there's a way to hard reset the threshold of how low the battery voltage can be within the APC 350.

I'll install the Powerchute software to see what's available to change monitor.

btw: I did drain the battery significantly after several hours on my 400W car inverter and my cheap volt meter continued to read ~12 volts (could have been 11-14 volts as the scale is hard to read). It took nearly 3 hours to recharge. The inverter & wires remained cool. I would think the APC is of better quality than my Xantrec inverter.]]> http://www.dslreports.com/forum/remark,19123521 Sat, 22 Sep 2007 09:21:32 EDT Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19123416 shortckt :
said by CajunWon See Profile :

...replacing the APC ES350 UPS battery with a standard car battery... Wondering why it only provides ~20 minutes of backup power?
I looked up the info on the model ES350 and while it is one of the economy models it appears to have on board cpu since it can perform weekly battery tests and has a serial port to use with software to shutdown a computer when power fails. That being said, my experience with APC UPS units is one of these possibilities:
1- the UPS is overheating after 20 minutes running and shuts down. Overheating is definitely possible with these ES models as they don't have any cooling fan and I don't think they even have any vents. The electronics and battery are all in one plastic box, and they have small batteries so are designed with the expectation the inverter will run for a short time.

2- it has been programmed to shutdown after battery reaches x% discharge (instead of full discharge). This and many other operating parameters can be changed/monitored by using the APC PowerChute software or APCUPSD open source software, the correct cable and a computer.

3- processor thinks battery has reached full discharge because it is calibrated for original size battery instead of battery 10x capacity of original. All APC 'smart' UPS devices need to be calibrated to the batteries once or twice a year as the battery ages, so the processor can calculate and report the remaining runtime correctly via software (or the front panel for those models that have one.) While not recalibrating could cause runtime to be mis-reported by 10-20% higher under normal circumstances, if you replace the designed battery with another having a capacity orders of magnitude larger, the processor's calculation becomes meaningless.

As you have seen, the battery voltage under load is not the only determining factor for UPS shutdown in the 'smart' devices. It will shutdown sooner than expected if the battery voltage goes below a set threshold, otherwise the programming sets the shutdown parameters.

One way to confirm the reason for shutdown is to connect a computer and use the software to monitor what the UPS is doing. Another test would be to put a power supply across the battery to prevent it from discharging while the UPS runs on battery.
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watchen das blinkenlights]]> http://www.dslreports.com/forum/remark,19123416 Sat, 22 Sep 2007 08:43:35 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19122539 Axilla : In fact when you start getting into big "12v" batteries for backup power applications they recommend float charge voltages that can be all the way up to 14.5 volts depending on the battery type. ]]> http://www.dslreports.com/forum/remark,19122539 Sat, 22 Sep 2007 00:11:40 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19122343 anon : Batteries that aren't meant for deep discharge will sulphate if they are deep discharged even once. Once they've begun to sulphate, it only gets worse.

A "12 volt" battery at 12 volts is quite low as fully charged they should be at about 13.8 volts. The UPS is gonna check the voltage to determine when the battery is getting discharged by checking the voltage. So although you have a higher capacity battery that could maintain current for longer at the lower voltage, the UPS has already decided the battery is nearly discharged and it's no longer safe to continue.]]> http://www.dslreports.com/forum/remark,19122343 Fri, 21 Sep 2007 23:29:59 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19121451 CajunWon : Thanks for the responses.

Starting battery, I had a spare for this test project. It's a marine grade battery.

AFAIK: Starting batteries are able to dump voltage faster as required as they tend to have more and thinner plates. But if high amps are not required then it shouldn't drop its' volt reading any quicker. Deep cycle & heavy duty batteries should be more difficult to sulfate the plates and therefore should recover from many near full discharges. But in my application, I should discharge the battery no more than once - 5 years, avg 5 2 hour black-outs/yr, & need no more than 1.7 amps with 1 amp avg.

I'm no EE so correct me where wrong.]]> http://www.dslreports.com/forum/remark,19121451 Fri, 21 Sep 2007 20:32:28 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19121251 drjim : Is this a Deep Cycle battery? If it's a "regular" starting battery, also called an SLI, it will have it's voltage drop faster under a constant load than a deep cycle battery will. It also won't last as long in this type of cyclic service as a deep cycle will.
--
One man's Magic is another man's Engineering.]]> http://www.dslreports.com/forum/remark,19121251 Fri, 21 Sep 2007 19:54:06 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19121193 SparkChaser : My guess would be that there is a voltage sense circuit that is monitoring the battery voltage and the marine battery is falling below what it (the APC) thinks a good battery is.
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"Facts do not cease to exist because they are ignored." - Aldous Huxley]]> http://www.dslreports.com/forum/remark,19121193 Fri, 21 Sep 2007 19:43:59 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19120521 CajunWon : How can I get hours, instead of minutes, from a large 'car type' battery attached to an APC UPS?

Especially considering the same battery then (without recharging) continues to power more equipment for many hours through a standalone 400W inverter.

My goal is to get extended protection from my APC UPS 'on the cheap'.]]> http://www.dslreports.com/forum/remark,19120521 Fri, 21 Sep 2007 17:43:41 EDT Re: Home UPS powered by car battery: failed http://www.dslreports.com/forum/remark,19119889 SparkChaser :
said by CajunWon See Profile :

Wondering why it only provides ~20 minutes of backup power?

Power died at the house today, so I plug my laptop into this UPS. ~20 minutes later I'm running off the Laptop battery alone. Then the APC 550/UPS which powers my router/modem/ATA begins the 1-sec interval beeping. I get that battery and connect a 400W inverter which powers: Laptop; Router; Cable Modem; VOIP ATA. It's still working great, hours later and I'm still working, calling, surfing. And the battery is still reading at least 12volts, cheap analog volt-meter.
I'm a bit confused as to what is happening. Would you restate the problem?
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"Facts do not cease to exist because they are ignored." - Aldous Huxley]]> http://www.dslreports.com/forum/remark,19119889 Fri, 21 Sep 2007 15:59:25 EDT Home UPS powered by car battery http://www.dslreports.com/forum/remark,19119779 CajunWon : I researched the possible side effects of replacing the APC ES350 UPS battery with a standard car battery. Those that found the risks acceptable claimed many hours and even days of stand-by backup power. I selected a Marine 665 Starting battery and made certain it had a full charge when connected.

Wondering why it only provides ~20 minutes of backup power?

Power died at the house today, so I plug my laptop into this UPS. ~20 minutes later I'm running off the Laptop battery alone. Then the APC 550/UPS which powers my router/modem/ATA begins the 1-sec interval beeping. I get that battery and connect a 400W inverter which powers: Laptop; Router; Cable Modem; VOIP ATA. It's still working great, hours later and I'm still working, calling, surfing. And the battery is still reading at least 12volts, cheap analog volt-meter.

edit: Didn't fail - user error.]]> http://www.dslreports.com/forum/remark,19119779 Fri, 21 Sep 2007 15:43:44 EDT