Problems powering notepad with UPS in cabin

[wagoo]

I've converted my cabin from 12- 240 volt Invertor power to direct 12 volt supply, running 12 volt LED downlights, TV etc.
The problem I'm having is powering my 19 volt notepad PC.
I've purchased two different brands of UPS this week, but neither seems capable of powering the PC. When switched on and connected up, I'm getting the required 19 volts out of the UPS into the computer, but the battery icons at the bottom of the screen alternate between pc battery and UPS at about 5 second intervals, and the screen brightness fluctuates annoyingly at the same rate. The PC battery eventually flattens at what appears to be the normal rate if operating on PC battery alone.The Wireless Modem (BigPond 7.2 Home Network Gateway} operates fine on the 12 volt supply.
Power supply is 2 heavy duty deep cycle 6 volt 150 AH each connected in series. Batteries together with charging Gen set are located 30 metres from cabin, and the connecting lead is heavy gauge house type wiring, so very little power loss.
It's frustrating having to run a 750 watt petrol powered generator just to power the PCs when everything else runs satisfactorily and economically on direct 12 volts.
Does anyone have an idea where my problem lies?
Thanks in advance.
Bill.

[abaddonxi]

How about a 12v car laptop power supply to step up from 12v to 19v?

[abaddonxi]

Something like this -
100W Universal Car Cigarette Powered Adapter/Charger for Laptop/Cell Phone/PDA - Free Shipping - DealExtreme (http://www.dealextreme.com/p/100w-universal-car-cigarette-powered-adapter-charger-for-laptop-cell-phone-pda-80881)

Although I wouldn't necessarily recommend Dealextreme for speedy delivery or reliability of product, or even guarantee that if it arrives it will be the right thing. Lovely surprise when their stuff turns up and works, though.:D

[Basil135]

30 meters for 12v seems to be a long way.

Have you actually checked the available amps & voltage at the end of the string?

IIRC, 20m is about the absolute maximum for 12v.

Also, what are the ratings of the UPS? You need to keep in mind that their primary function is to allow a soft shut-down of computers in the event of a mains fail. I am guessing that you are using the batteries in the UPS, through its own inverter, to give you power to plug your laptop adaptor into.

Your other alternative is to get some bigger batteries for the UPS, and then charge them from a solar panel.

[austastar]

Hi,
I have just bought a 12V universal power supply from Jaycar for my Lenovo laptop.
Previously I was running it satisfactorily via a elcheapo Dick Smith 150W inverter with no worries, but was trying to get better battery economy and get rid of some of the wires.
I'm very happy with the 12-19V step up, my only complaint is the plug is easier to dislodge than the original 240V power supply plug, but it beeps to let you know.
The beeping does drive the Mrs nuts if she is using it on her lap to navigate though.

I would recommend the Jaycar 12V power supply.

cheers

[Lotz-A-Landies]

You should have set up the camper to run on 24V, then you would be stepping down to 19V.

[wagoo]

Thanks for the replies, but now i'm confused:confused:. What I've been calling a UPS is in fact the cigarette lighter socket car DC adaptor for laptops.
I haven't charged the batteries for around 24 hours but just checked the voltage readings at the batteries and the DC adaptor. There is some loss, 11.6 volts at batteries vs 11.2 volts at DC adaptor input.Still reads 19.2 volts at DC output.
I'll drag it all out and try it in my vehicle later. Bloody hell! It's supposed to be 'Wireless Internet' but it's like spaghetti junction around here.
Bill.

[Tombie]

Thanks for the replies, but now i'm confused:confused:. What I've been calling a UPS is in fact the cigarette lighter socket car DC adaptor for laptops.
I haven't charged the batteries for around 24 hours but just checked the voltage readings at the batteries and the DC adaptor. There is some loss, 11.6 volts at batteries vs 11.2 volts at DC adaptor input.Still reads 19.2 volts at DC output.
I'll drag it all out and try it in my vehicle later. Bloody hell! It's supposed to be 'Wireless Internet' but it's like spaghetti junction around here.
Bill.

Bill - You're referring to a Universal Power Supply (DC to DC converter)

What a UPS actually is, is an Uninterrupted Power Supply for Server PCs etc..

This is where its lost in translation!


I'd suggest you are either running low on power of that cable length (What actual size cable are you running?)

Or your DC->DC converter is not capable of pushing enough current for your laptop.

Take a look at your Laptops Mains power supply - What current output was it??? 19v @ ???amps...

Perhaps the new supply is not up to the task....

[wagoo]

Thanks for clearing up my misunderstanding Tombie.
I set it all up in my vehicle and it worked fine, so as you say, the length of the cable is the culprit. Aside from the 30 metre long lead from battery supply to cabin, there may be that much again in the cabin wiring before it reaches the wall sockets.
The DC convertor has a capacity of up to 24 volts at 3.5 amps.
The mains supply to the laptop is 19 volts at 3.42 amps.
Thr connecting lead wire diameter is around 2.5 mm, 4mm insulation diameter.
Interior cabin wiring is similar.
Looks like I'll have to move the batteries and noisey Briggs powered generator much closer to the cabin. But at least I should only have to fire it up much less frequently than when using the invertor.
Bill.

[fraser130]

Wagoo, what are you charging the big batteries with?
If it is a 240v charger, leave the genny miles away, and run the 240 to the charger which is next to the batteries, which can be right next to the shed, you will get almost no voltage drop over even 60m of good quality extension leads if you are only powering a 240v -12v charger for your batteries.....just a thought

Fraser

[wagoo]

Wagoo, what are you charging the big batteries with?
If it is a 240v charger, leave the genny miles away, and run the 240 to the charger which is next to the batteries, which can be right next to the shed, you will get almost no voltage drop over even 60m of good quality extension leads if you are only powering a 240v -12v charger for your batteries.....just a thought

Fraser

Fraser, I have a 65 AH Bosch alternator driven by an 8hp petrol engine.Actually the alternator is fitted to my walk behind grass slasher. How far could I park that away from the batteries?
I charge and use the batteries in individual pairs, and I have 8 pairs in total.
I've tried connecting all the batteries together as one large 12 volt bank, but it kills alternators and loads the engine for too long when it comes time to recharge.
Bill.

[fraser130]

In all honesty Bill, I would go for a small 240v Genset running a "smart" charger, and have all the batteries connected as one bank, batteries are expensive, and I wouldn't risk them with just a car alternator doing the charging, or mucking about with swapping pairs about.

But to answer your last question, not far, and you will have even higher current through the cable from the alternator, so it will not get an accurate "feeling" for the voltage of the batteries.

If I have read your first posts correctly you have 8 pairs of 150Ah batteries, so thats a total of 1200Ah at 12v, so if you have them all connected together as a 12v bank, you are safe to pump 120A into them for at least 10 hours if they were flat!
That's a hell of a lot of current and stored power.

There are some good inverter/charger combined units about at the moment that can charge at 50A, and you would be looking at least 24 hours of straight running to charge the batteries from flat.

Now, a 50A charge at 12v would require a 600w genset (in reality you would want around 1Kva)
at 120A you need 1.4Kw (again probably a 2Kva genset, but you would be hard-pressed to find a 120A 12v charger)

Now as I'm sure you know it's not good practice to use more than the top 10% of charge if you want the batteries to last, so we are looking at 120Ah, so a 50A charger would replace that in only 2.4 hours.
If you had a 25A charger (300w at 12v), it would take 5 hours to charge that 10% and it could be run by a very small genset (a 500W one would do).... (in reality it is longer, but you get the idea..) all of this would allow the genny to be a long way away, and not suffer from voltage drop....

I hope some of that helps.......

Cheers,
Fraser

[wagoo]

Thanks very much Fraser, that is all very helpful information.
To be honest, I didn't know that 240/12volt battery chargers were available in such high ratings.
Bill.

[fraser130]

Thanks very much Fraser, that is all very helpful information.
To be honest, I didn't know that 240/12volt battery chargers were available in such high ratings.
Bill.

Bill, I have one of these (http://www.ebay.com.au/itm/PROJECTA-7-Stage-25A-battery-charger-IC2500-4x4-4WD-/110786827210?pt=AU_Car_Parts_Accessories&hash=item19cb68d3ca) and it's excellent, very efficient too.
I have since noticed these (http://www.ebay.com.au/itm/Xantrex-TrueCharge2-Battery-Charger-40A-3-Bank-12v-Global-AC-Input-/120823806114?pt=LH_DefaultDomain_0&hash=item1c21a8f8a2) too.... there are others about too...

[fraser130]

Just for interest Bill, where did you get your batteries from?
I have a mate who is setting up a shed on his new property to live in, and I'm the guy who's doing it for him......

Cheers,

Fraser

[wagoo]

Just for interest Bill, where did you get your batteries from?
I have a mate who is setting up a shed on his new property to live in, and I'm the guy who's doing it for him......

Cheers,

Fraser
Fraser.
The batteries were given to me by a mate and neighbor who used to work for Telecom, who replace batteries on a schedule rather than as needed basis.
My collection is probably getting a bit long in the tooth, and I've been charging them as a single 12 volt bank for the past 2 years with an 80 ah alternator fitted to an additional belt pulley on my 6kva gen set powered by a larger 18 hp petrol engine.The engine failed about 4 weeks ago, and I figured I had more power than was required for battery charging, and the 6kva wasn't really sufficient for welding,(I have a larger genset for those tasks), Hence the fitting of the 65 amp alternator to my 8hp grass slasher.

I'm a little concerned at the amount of power the DC/DC convertor uses.
I made a 4metre long, heavy cable and placed a partially charged {11.6 volt} 12 volt 100Ah deep cyle battery close to the cabin as a trial.
With the PC battery removed and only the Modem and DC convertor connected to the 12 volt battery I only get 2 hours of operation before the PC shuts down due to insufficient power.Unconnected the battery reads 10.03 volts 4 hours after shutdown.
The whole purpose of trying to run everything on 12 volts was so that I could lose the power hungry 1000 watt invertor that i've been using to power everything for the past 2 years, that was costing me a jerry can of fuel a week to keep the battery bank topped up sufficiently to prevent the invertor fom shutting down. So far, and due only to the computer it appears that I'm no better off.
i've just connected up the small 370 cca battery out of my wifes Honda, which currently reads 13 volts when connected.I'll see how long til shutdown.
Bill.

[fraser130]

Bill, 11.6 Volts is a flat battery!
Just for interest, is the laptop adapter getting hot? If it's not, then it's working efficiently, as any power it actually uses is given off as heat.
I've attached a little file showing what voltage equals how much charge.....

What brand/model number is your adapter? Mine is fantastic, and barely gets warm during use.

http://www.aulro.com/afvb/attachment.php?attachmentid=41362&stc=1&d=1323300266


If ever you can get any more batteries, be sure to let me know!!;)

Cheers,
Fraser

[wagoo]

Thanks for the chart Fraser. That is very interesting and I'm very surprised that the % of charge drops so dramatically with barely 1 volt difference between full and flat.
I have 2 brands of DC adaptors. a Power Tech Plus mp3463 one and a Ritmo brand KC195 digital output voltage readout type one.The Power Tech one that has been on for about 5 hours is still room temperature. I haven't tried the other one for more than 2 hours but don't think it got hot. I'll try it later once i know how long the Honda battery lasts until shutdown.
I'll certainly let you know if anymore batteries become available. Somebody told me that it's worth checking with golf courses, as they replace buggy batteries at scheduled periods.I haven't personally done so.
Where is your friends property? I am in the hills of Dixons Creek.
Bill.

[abaddonxi]

That Ritmo one looks like it's got enough zzz's to power anything.

https://secure.vividcluster.crox.net.au/jaycar2005/productView.asp?ID=MP3463&keywords=mp3463&form=KEYWORD

Ritmo Online (http://ritmotech.com.au/satotech/product_info.php?products_id=533&osCsid=e88d357918be98ab80afc9ed03f9b445)

How's the cigarette adapter? Maybe losing some at that connection?

[wagoo]

That Ritmo one looks like it's got enough zzz's to power anything.

https://secure.vividcluster.crox.net.au/jaycar2005/productView.asp?ID=MP3463&keywords=mp3463&form=KEYWORD

Ritmo Online (http://ritmotech.com.au/satotech/product_info.php?products_id=533&osCsid=e88d357918be98ab80afc9ed03f9b445)

How's the cigarette adapter? Maybe losing some at that connection?

Good secure contact and good quality double socket with heavy wire.
This has been an education for me.Aside from battery voltage readings, which are a bit misleading when the battery has just come off the charger, i'd always assumed that if the engine RPM on my ungoverned engine didn't increase when I disconnect the battery from the alternator, then that was all the charge that the battery would accept. It would appear that until I can afford a decent size 240/12 volt battery charger and good quality 1 kw genny, that I will need to charge individual battery pairs in stages with around a 45 minute break each time, as that seems to be the time lapse before I get an accurate voltage reading.
Bill.

[fraser130]

Bill, if you feel like a read:
Click here (http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery)

I have an older powertech unit (black with one straight edge, and one round edge) and it is great.
Sounds to me like the input voltage is too low, and the unit is turning off, thus removing the load, so the supply voltage comes up, and it then turns back on, etc, etc, etc.
I think they will turn off around the 12v mark to save completely draining you batteries.....

My mate's place is in mid-western Vic, just south of Horsham in the middle of nowhere, so he needs a batt/jenny/solar setup to run a computer for work (he does 6 months on, 6 months off in the Pilbra) and I'm trying to get a good setup together for min price as he is struggling to pay off the land.....

Cheers Bill, and if you think I can help in any way, feel free to ask........

Cheers,

Fraser

[wagoo]

Thank you once again Fraser. Your assistance and shared knowledge is much appreciated.
Well the DC adaptor finally shut down power from the little Honda battery after 8 hours and 20 minutes of continuous operation. That seems quite acceptible considering the small size of the battery, which still gave a voltage reading upon shutdown of 12.13 volts. More than enough to restart the car. The highest state of charge I have acheived today with the afore mentioned single 12 volt 100AH battery is 12.20 volts after 3 hours on the alternator. Perhaps it has developed a memory due to never being fully charged for the past couple of years? When this battery was connected to the Ritmo DC adaptor previously, it shut down after 2 hours at a much lower voltage reading (10 volts), so could it be that amps rather than voltage is the factor that determins when shutdown occurrs? Bill.

[Blknight.aus]

The alternator will charge your batteries quite happily if its set up correctly

using engine rev drop/raise to measure if you've charged your batteries is a bad idea as you're basically dropping the batteries off charge when they've just finished taking in a bulk charge (which is usually said and done by about 70%soc) after that point the amps that a battery will pull out of an alternator drops off but they still are accepting a charge from the alternator.

my field method for checking the batterys charge rate is with a bank of lights ranging from 21w up to about 60w if the alternators charge cable is cool enough for me to grab by hand I just drop the lights in series with the alternator and the batteries if the lights dont glow I go to the next one down.

a better way of doing it is with an induction amp meter or a clamp meter similar to 400A AC/DC Clampmeter - Jaycar Electronics (http://jaycar.com.au/productView.asp?ID=QM1563&keywords=amp+meter&form=KEYWORD)

with the size of the bank you're running you could happily run 200A alternator or run a series of alternators in parrallel.

[wagoo]

The alternator will charge your batteries quite happily if its set up correctly

using engine rev drop/raise to measure if you've charged your batteries is a bad idea.

Thanks Dave. To be honest it's not something I have done more than on a couple of occasions, and only since using the smaller engine, when I noticed , due to noise and engine revs that the engine was no longer working hard.
Bill.

[fraser130]

Bill, lead-acid batteries don't have a "memory" as such, but they really, really don't cope with being stored in any condition other than fully charged.
If only you were closer I'd be happy for you to drop them off here a pair at a time, and give them a proper full charge, then check the voltage on them after letting them sit for a day....I suspect you may have a dead cell or two in each pair, or they are just not getting enough time on the charger to get there, or the alternator's regulator voltage is too low.
Is there any chance you can take them somewhere with mains and use a good charger to give them an "equalising" charge, then let them sit for a day,m then check their voltages? You might be just flogging a dead horse at this stage.
Is the meter you are using to measure them fairly accurate?
As Dave said, the charging current drops off well before the battery is full, and unfortunately, it just takes time to get there.
On another note, you can get this (http://www.xantrex.com/power-products/power-accessories/alternator-regulator.aspx) sort of thing to use with your alternator, and it will give you feedback as to where your batteries are, and protect your alternator.
Hmmmmmmm

Fraser

[wagoo]

Fraser, I'll take a pair to a mates place down on the highway a bit. He's on the grid and we can give them a charge and test them after 24 hours.I think the regulator on the alternator is allowing full charge because when i plug a flattish deep cycle battery on to it the engine loads up significantly and will stall if i don't have it on at least 3/4 throttle for a while.

Meanwhile, The Ritmo adaptor has turned out to be a hunk of Chinese junk.It has flattened another but slightly larger 13 volt automotive battery in 2 hours, and the adaptor itself has got quite warm compared to the Power Tech version.
Bill.

[Bearman]

See you have that keyboard sorted out Bill:)

[fraser130]

Fraser, I'll take a pair to a mates place down on the highway a bit. He's on the grid and we can give them a charge and test them after 24 hours.I think the regulator on the alternator is allowing full charge because when i plug a flattish deep cycle battery on to it the engine loads up significantly and will stall if i don't have it on at least 3/4 throttle for a while.

Meanwhile, The Ritmo adaptor has turned out to be a hunk of Chinese junk.It has flattened another but slightly larger 13 volt automotive battery in 2 hours, and the adaptor itself has got quite warm compared to the Power Tech version.
Bill.


Good to know, I'll not buy one of those if I ever need another...My older Powertech gets slightly (only just noticeable) warm when running my laptop and charging it's battery.

[wagoo]

See you have that keyboard sorted out Bill:)

Yes, a 30 dollar keyboard from officeworks fixed the problem.If only my power supply issues were so cheap and easy to sort out.:(
Bill.

[wagoo]

Hi,
I have just bought a 12V universal power supply from Jaycar for my Lenovo laptop.
Previously I was running it satisfactorily via a elcheapo Dick Smith 150W inverter with no worries, but was trying to get better battery economy and get rid of some of the wires.
I'm very happy with the 12-19V step up, my only complaint is the plug is easier to dislodge than the original 240V power supply plug, but it beeps to let you know.
The beeping does drive the Mrs nuts if she is using it on her lap to navigate though.

I would recommend the Jaycar 12V power supply.

cheers

Is there a significant difference in power consumption between the invertor and the DC adaptor ?
I ended up having to buy a Power Tech inverter to power my daughters high school leased Apple Mac laptop because no one including Apple themselves seems to make or sell a DC adaptor with a 4 pin flat plug to suit.
Bill.

[wagoo]

Is there a significant difference in power consumption between the invertor and the DC adaptor ?
I ended up having to buy a Power Tech inverter to power my daughters high school leased Apple Mac laptop because no one including Apple themselves seems to make or sell a DC adaptor with a 4 pin flat plug to suit.
Bill.
I think my question has just been answered.The inverter has just shut power off to the daughters laptop after only 4 hrs. And that is with 2 13 volt car batteries in parralell.
My previous arrangement of battery bank/1000watt inverter 240 volt supply to everything was less power hungry than what I have now.:mad:
Bill.