Power is out and I'm online.

Posted by: Blast

Power is out and I'm online. - 02/16/12 02:58 AM

A transformer blew up half an hour ago, knocking the power out to our neighborhood. DD1 is currently doing math problems by the light of a 12vdc LED array plugged into an old 450 amp "Power On Board" portable car battery jumpstarter and I'm using my wireless notepad to connect to the internet through our wireless router and DSL modem powered by a Xantrex "Powerpack 400Plus" which is kept charged by a 30-watt solar panel.

-Blast
Posted by: bacpacjac

Re: Power is out and I'm online. - 02/16/12 03:15 AM

NICE! Gotta love being prepared. Unless maybe you're 8 and not getting out of homework. :-)
Posted by: Blast

Re: Power is out and I'm online. - 02/16/12 03:24 AM

Originally Posted By: IzzyJG99
That's one upside to DSL's. They use the telephone system is independent and often powered by another sector of the grid not affected, so they stay up.


Yep, DSL for the win. I have a stopwatch running to see how long I can power the modem and router. DD1 finished her homework and is in bed so if need be I can use that powerpack along with the 12vdc plug for my netbook to go well in to the night...or me and DW could go to bed early. whistle

-Blast
Posted by: ireckon

Re: Power is out and I'm online. - 02/16/12 03:26 AM

My high speed cable stays on during power outages, as long as my in-house components are powered.
Posted by: bacpacjac

Re: Power is out and I'm online. - 02/16/12 03:32 AM

Originally Posted By: Blast
...or me and DW could go to bed early. whistle

-Blast


Boom chicka wow wow! Blast for the win!
Posted by: Chisel

Re: Power is out and I'm online. - 02/16/12 03:40 AM

Well, Blast, my preps for power failures are much simpler .
There is only one option on the menu : go to bed early ...

And it is my favorite option, LOL.
Posted by: haertig

Re: Power is out and I'm online. - 02/16/12 03:48 AM

I play piano or read during power outages. I have plenty of LED lights to illuminate those activities if it's too dark to see. Also, sitting in the dark and listening to long-forgotten favorite songs on an MP3 player is fun.
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/16/12 04:32 AM

Generally, my response is: all is as it should be. Nothing to see here. Move on.

My interweb is fixed wireless, so I doubt I would have service for more than a day. The landline phone would keep going, though, along with basic internal power (based on solar in the short term and a small genny thereafter. I'd have a crude dial-up account running by that point, to feed my addiction. Then there's the wood stove, the library, and the old six-string for heat, light, and entertainment. Mostly a nuisance, unless it was -38C outside.

For Blast, though, I would provide a caution (an old proverb I believe), which runs something like of "going to bed early to save candles isn't economical if twins are the result."
Posted by: CANOEDOGS

Re: Power is out and I'm online. - 02/16/12 07:36 AM

nice to read that someone out there is really prepared.
Posted by: Blast

Re: Power is out and I'm online. - 02/16/12 03:29 PM

After 2 hours and 10 minutes I still had 60% of the charge left in the Xantrex. DD1 finished her math worksheet after 30 minutes, but I didn't check the power left in that battery.

Anyone know of a 12vdc wireless router? Google didn't turn up anything but I wasn't looking too hard. The energy lost from converting back and forth between AC and DC annoys me.

It's a cloudy day today so it'll be a good test to see how well my solar panel can recharge the 400 amp battery. My panel is flat against a south-facing, 2nd floor winder so it isn't optimized for sun exposure. Results will be posted this evening...unless me and DW go to bed early again. grin

-Blast
Posted by: Russ

Re: Power is out and I'm online. - 02/16/12 03:59 PM

Don't all routers run on DC? I have a power supply/transformer thing that plugs into the wall and provides DC to the router. It may be just a matter of having the right voltage and a plug (which you probably have, it just needs to be dismembered wink ).
Posted by: Blast

Re: Power is out and I'm online. - 02/16/12 04:28 PM

Originally Posted By: Russ
Don't all routers run on DC? I have a power supply/transformer thing that plugs into the wall and provides DC to the router. It may be just a matter of having the right voltage and a plug (which you probably have, it just needs to be dismembered wink ).


Hmmm, looking at these specs I should just be able to splice the proper barrel plug onto a 12vdc "cigarette lighter" plug and be good to go? Then checking the specs of our DSL modem, I might be able to do the same for it.

-Blast (hoping not to live up to his name this time)
Posted by: Eugene

Re: Power is out and I'm online. - 02/16/12 05:06 PM

Generally your safe. since a 120v to 12v wall transformer is pretty simple the router has an internal regulator. Since 120v power can fluctuate, say from 100v to 130v your input at the router can be from 11v to 13v. usually there is a 5v regulator inside anyway. If you ant to be extra safe get a 12.5 or 13v zener diode and put across your 12v cord to prevent anything higher from getting through (say if you were to run a car alternator to charge your battery where you could hit 14.whatever volts.)

AT&T bought our local phone company a few years ago so the land line ceased to stay alive for very long when power was out and wasn't very relaible when there was power so we swiched to an all in one cable bundle. I've used the power companies web site to verify outage maps and report my power was out.
Posted by: haertig

Re: Power is out and I'm online. - 02/16/12 06:33 PM

If you want to conserve power, skip the wireless router and plug your computer directly into your modem with a CAT-5 cable. Be sure to turn off your computers wireless antenna too (to save additional power).
Posted by: Russ

Re: Power is out and I'm online. - 02/16/12 07:06 PM

Yep, IME wireless is good for about ~50 Mbps while Ethernet is good for 100 Mbps. I keep my laptop wireless radio turned off and use Ethernet exclusively.
Posted by: chaosmagnet

Re: Power is out and I'm online. - 02/16/12 07:52 PM

Originally Posted By: Russ
Yep, IME wireless is good for about ~50 Mbps while Ethernet is good for 100 Mbps. I keep my laptop wireless radio turned off and use Ethernet exclusively.


Wired Ethernet is good for anywhere between 10 Mb/s half-duplex and 1 Gb/s full-duplex with most laptop NICs. With reasonably recent devices you're most likely going to see 100 Mb/s full-duplex. Those are nominal connection speeds; the switch, cabling and PC will limit actual throughput to 90% (ideally) or much less of the negotiated or configured speed.

Wireless Ethernet tops out at about 250 Mb/s, but that's a rare speed to get. Much slower speeds are more common, down to 1 Mb/s. Most wireless access points share a very limited pool of bandwidth with all connected devices, and don't do that well.

In most home networks wireless and wired speeds are much greater than Internet connection speeds, so which you use doesn't matter from a speed perspective unless your traffic is going between devices on your network, rather than from your PC to and from servers on the Internet.

Wired Ethernet almost always consumes less power. While this is unlikely to matter for your power bill or if you're running a generator, it could easily start to matter if you're running on battery power.
Posted by: airballrad

Re: Power is out and I'm online. - 02/16/12 08:02 PM

Originally Posted By: chaosmagnet
Wired Ethernet almost always consumes less power. While this is unlikely to matter for your power bill or if you're running a generator, it could easily start to matter if you're running on battery power.


^^This

That said, to answer Blast's question, there is this, provided your wireless adapter's amp draw is not too great:

http://www.amazon.com/12V-2A-DC-Converte...777&sr=1-14

On the larger topic: when we had our generator installed I made a point of getting the circuits powering our household telecom infrastructure on the transfer switch. When our power was out and I had to call the local DPW about a sewage backup I had to walk up the road to make a cell call because the landline phone's backup had run down. mad
Posted by: Blast

Re: Power is out and I'm online. - 02/16/12 08:43 PM

Originally Posted By: airballrad
That said, to answer Blast's question, there is this, provided your wireless adapter's amp draw is not too great:

http://www.amazon.com/12V-2A-DC-Converte...777&sr=1-14

Hmm, that looks very interesting but after digging around some it seems I need 13-14 volts feeding into it to get the 12V out. My battery system puts out 12-13V. Will it still power my router?
http://www.powerstream.com/dc6.htm

-Blast
Posted by: Mark_R

Re: Power is out and I'm online. - 02/16/12 08:50 PM

Originally Posted By: haertig
I play piano or read during power outages. I have plenty of LED lights to illuminate those activities if it's too dark to see. Also, sitting in the dark and listening to long-forgotten favorite songs on an MP3 player is fun.


Read, fancywork (Kevingg isn't the only paracord addict here), trombone, etc. Speaking of LEDs, I just replaced the bulbs on the old 2D incandescent flashlights with 1/2 watt LEDs. $9/each at Home Depot and I've got 25 lumen floods with a 40+ hour usable battery life and a massive spillbeam. Perfect for power outages.
Posted by: airballrad

Re: Power is out and I'm online. - 02/16/12 09:01 PM

My experience with these things is that a auto cigarette lighter-style plug means that 12V will power it, as long as it's not drawing more than about 10A. I even have a large spotlight with a lighter plug that my small jumper pack will run, albeit not for long. I can't say for sure as I haven't used this product, but the price is such that I'd say it's worth a try.
Posted by: chaosmagnet

Re: Power is out and I'm online. - 02/16/12 09:19 PM

Nominal output for a "12V" DC cigarette lighter is 13.8V. The wall wart that you're using has 12V DC output @ 1A. Your existing 12V DC power systems should work fine if you use the right adapter with the right polarity.
Posted by: Eugene

Re: Power is out and I'm online. - 02/16/12 10:54 PM

Most 12v wall warts are 12v nominal but line voltage can fluctuate so that 12v can up op or down. ~12v is close enough.
Posted by: Blast

Re: Power is out and I'm online. - 02/17/12 01:53 PM

Originally Posted By: Blast
It's a cloudy day today so it'll be a good test to see how well my solar panel can recharge the 400 amp battery. My panel is flat against a south-facing, 2nd floor winder so it isn't optimized for sun exposure. Results will be posted this evening...unless me and DW go to bed early again. grin


Just an update, the battery was fully recharged last night, even with the very sub-optimal solar conditions.
-Blast
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/17/12 04:04 PM

Originally Posted By: chaosmagnet
Nominal output for a "12V" DC cigarette lighter is 13.8V. The wall wart that you're using has 12V DC output @ 1A. Your existing 12V DC power systems should work fine if you use the right adapter with the right polarity.


Maybe. But some electronic equipment requires a much more closely regulated DC voltage. The only way to know is to measure the "no load" voltage from the manufacturer-supplied wall wart, and compare it to the rated voltage output (which is under load). If it's sitting right at 12 VDC, it's a regulated supply, and supplying a higher voltage could cause damage.

(IMO, a decent multimeter is indispensable gear for any solar setup, for checking actual voltage, monitoring for overcharging, and confirming correct polarity.)

P.S., Blast, what's the watt rating of your solar panel? Are you using a charge controller?
Posted by: Blast

Re: Power is out and I'm online. - 02/17/12 04:44 PM

Originally Posted By: dougwalkabout
P.S., Blast, what's the watt rating of your solar panel? Are you using a charge controller?


It's a 30 watt panel which plugs directly into the charging port of my Xantrex Powerpack 400Plus without a charge controller. According to the Powerpack's manual, this is okay to do with any solar panel of 30 watts or less. It's been hooked up this way for just over a year now with no problems.
-Blast
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/17/12 05:14 PM

"According to the Powerpack's manual, this is okay to do with any solar panel of 30 watts or less."

That's interesting. The newer SLA batteries must be a lot more resistant to overcharging. I had to sit on the old ones like a mother hen.
Posted by: Russ

Re: Power is out and I'm online. - 02/17/12 06:59 PM

On the topic of solar panels, what the difference between polycrystalline solar panels, mono-crystallin​e solar panels and amorphous solar panels?
Posted by: Blast

Re: Power is out and I'm online. - 02/17/12 07:50 PM

Originally Posted By: Russ
On the topic of solar panels, what the difference between polycrystalline solar panels, mono-crystallin​e solar panels and amorphous solar panels?


In a nutshell, the amount of power produced per unit of area (footprint). The same surface area of the different crystal types produces different amounts of power, but I don't remember off the top of my head which gives the most/least.
-Blast
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/17/12 08:11 PM

I'm using amorphous (thin film) panels. They're the least efficient per square foot, the least expensive, and probably the heaviest. Space and weight are not big issues for me, so I go with the "best price per watt."

There are so many big advances nearing production, and such an increase in production scale, that I'm not willing to buy more panels right now. Cost per watt is slated to drop substantially (that's the buzz anyway).
Posted by: chaosmagnet

Re: Power is out and I'm online. - 02/17/12 08:38 PM

Originally Posted By: dougwalkabout
Maybe. But some electronic equipment requires a much more closely regulated DC voltage. The only way to know is to measure the "no load" voltage from the manufacturer-supplied wall wart, and compare it to the rated voltage output (which is under load). If it's sitting right at 12 VDC, it's a regulated supply, and supplying a higher voltage could cause damage.


I didn't think that wall warts that size were usually regulated power supplies.

Quote:
(IMO, a decent multimeter is indispensable gear for any solar setup, for checking actual voltage, monitoring for overcharging, and confirming correct polarity.)


Without a doubt.
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/17/12 11:08 PM

Originally Posted By: chaosmagnet
I didn't think that wall warts that size were usually regulated power supplies.


Fair comment. Most of them aren't.
Posted by: Slatu

Re: Power is out and I'm online. - 02/18/12 04:51 AM

Dougwalkabout's "amorphous (thin film) panels" are also great because of their surface area, so they perform better in cloudy conditions. I'd be careful of saying Blast's batteries were topped-off from a single day's sun from a 30watt panel without knowing the amp-hour capacity of the batteries. Remember we are playing with electrical energy and chemical energy in solar/batter systems.
Posted by: Blast

Re: Power is out and I'm online. - 02/18/12 05:02 AM

Originally Posted By: Slatu
Dougwalkabout's "amorphous (thin film) panels" are also great because of their surface area, so they perform better in cloudy conditions. I'd be careful of saying Blast's batteries were topped-off from a single day's sun from a 30watt panel without knowing the amp-hour capacity of the batteries. Remember we are playing with electrical energy and chemical energy in solar/batter systems.


It's a 20 amp-hour battery which was only 40% discharged (putting out 12.3 V) according to my battery monitor. After one very cloudy day my 30-watt solar panel had brought it back up to 100% charged (12.83 V) according to the same monitor.

My Xantrex Powerpack 400Plus.
My battery monitor.
My monocrystalline 30-watt solar panel.

-Blast
Posted by: Slatu

Re: Power is out and I'm online. - 02/18/12 05:46 AM

A voltage monitor isn't the perfect fuel gauge of a DC system. I'll try to make a new solar/battery topic tomorrow, and keep kids doing homework no matter what excuse they can find.
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/18/12 07:39 AM

Sure, the only real test is to measure the voltage under a load of suitable size for the battery's rated capacity.

(Example: a neighbour can't get his tractor to start. He has a DVOM, and it reads 12+ volts. So the battery must be okay, right? I get him to read the voltage while I turn the key, engaging the starter. 4 volts under load. Time for a new battery. Checked the charging system output after, just in case; it was fine, kicking out 14+ volts.)

It isn't always possible to test with a suitable load. But if you know your battery's general range, you can get a working indication of its overall status. I like to monitor charging with a multimeter. If a lead-acid battery on my solar panels will achieve just over 14 VDC, that's a full charge. The SLAs I've used will typically drop to 12.8 after charging terminates. However, if a batt comes close to full charge and then suddenly cascades to 15+V, it's probably reached the end of its normal service life.

BTW, here's an idea:
A particularly interesting topic for this forum would be "bring out your dead ... batteries." I.e., how to get value/use out of different types of batteries, rechargeable and single use, that are technically dead (hopelessly out of their design range) but can still be used to accomplish useful work in an emergency. I have some field experience in this ...
Posted by: Blast

Re: Power is out and I'm online. - 02/18/12 09:27 PM

Quote:
Sure, the only real test is to measure the voltage under a load of suitable size for the battery's rated capacity.


How does one do this?
-Blast
Posted by: chaosmagnet

Re: Power is out and I'm online. - 02/19/12 06:03 AM

One measures voltage across the terminals of the battery. If the voltage under load is close to the same as when it isn't under load, your battery is in pretty good shape.

Battery testers that do not measure under load are pretty common, but unfortunately aren't particularly useful. Good battery testers always introduce a load.
Posted by: Nomad

Re: Power is out and I'm online. - 02/20/12 03:53 AM

Originally Posted By: Blast
Quote:
Sure, the only real test is to measure the voltage under a load of suitable size for the battery's rated capacity.


How does one do this?
-Blast


I use an inverter and various loads like a hair dryer. Or a dc water pump etc. I find something that develops the load I need. Sometimes I use large wire wound resistors that I find at "specialty" (electronic junk) shops.

I have several shunt operated amp meters to monitor the current and a standard digital meter for the voltage. Shunt meters are easy to make and work well.

The hard part is making sure you are around when the battery reaches the desired "discharged" point. this varies depending on the type of test you want to run. Not hard to make a small arduino (small computer used in robotics) voltage/current monitor that alarms when the set discharge conditions are met.

I can go into it in depth if you are really interested. I live off the grid and do a lot of solar/battery stuff.

What exactly do you want to test??

Nomad
Posted by: Nomad

Re: Power is out and I'm online. - 02/20/12 03:58 AM

Originally Posted By: Blast
<snip>
Anyone know of a 12vdc wireless router?
-Blast


Most of the routers work at either 12 or 5vdc. Check the wall wart output voltage. I run several 5v ones using just the standard "3 leg" 5v regulator mounted on a small heat sink.

Nomad
Posted by: dougwalkabout

Re: Power is out and I'm online. - 02/21/12 09:02 PM

Originally Posted By: Blast
Quote:
Sure, the only real test is to measure the voltage under a load of suitable size for the battery's rated capacity.


How does one do this?
-Blast


I'm always leery when doctors o' philosophy ask simple, innocent, open-ended questions. A little alarm bell goes off in my head, warning that I may wind up on the short end of a Socratic dialogue. wink

Without the manufacturer's specs at hand, it's hard to determine an ideal load. A 20 Ah battery is not that large, and there's a fine line between a load that's large enough to test the battery strength and a load that will overheat/damage the battery.

The safest route is to use the on-board inverter as your load. It has built-in protective circuitry. Plug in an item that's near its maximum capacity, and then measure the DC voltage of the battery. If the voltage holds well, you have a good battery and charge; if it drops like a stone, you have either a weakened battery or incomplete charge.

Another option is to charge your batteries on the solar panel, let them rest a short while, then use the wall charger supplied with your unit. These usually kick off when a full charge is achieved.

As for field expedients, a DC motor (e.g., large bilge pump) would work. I think an old-style sealed automobile headlamp would be quite viable (IIRC, these pull somewhere around 5-6 amps). Connect it, measure the voltage, and disconnect.

A last caution: these batteries are not deep-discharge types. Discharging them too deeply causes damage. If you're using the inverter, it will alarm and shut down when the voltage becomes dangerously low. This is just under 11 volts IIRC. If you're using direct DC, there will not be an alarm or automatic shutdown; you have to stay on top of it.