Backup Power Battery for ADSL modem 2+ hours minimum required...

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Digs

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#11695 6-Feb-2007 18:13

My setup..

ADSL modem..
laptop

I need to run code 24/7, 5 days a week and I must have internet connection via ADSL for this.

The laptop has a battery, and can give me 4 hours of run time if power goes off.(Toshiba A7)

The ADSL modem has no battery. So what can I do to get back up power for the ADSL modem for at least 2 to 4 hours. do batteries last this long ????

So if power goes down I hope to have 4 hours back up so that I can still be connected to internet and laptop can still run the code.

Note: Its another question if ISP goes down..let work on power issue here first.

Please advise

Thanks...

freitasm

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#59889 6-Feb-2007 18:18

You are looking for a UPS. Belkin UPS are good devices, and providing you are only powering the ADSL modem then it should last quite a long time. Still the specs for the 1200VA Universal says a maximum of 100 minutes.

Digs

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#59890 6-Feb-2007 18:32

Awesome...thx

grant_k

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#59903 6-Feb-2007 20:30

If you want a longer backup time than a UPS can provide (100 minutes as Mauricio says), another way is to buy a 12 Volt Deep Cycle Marine battery and a 12 Volt Battery Charger. Then buy a 300 Watt 12VDC to 230VAC inverter from DSE. Earlier I tried a 150 Watt one but it was crappy and failed after only using it a few times.

This should give you more than a day's backup if you get a big enough battery and only want to run your laptop and a modem.

Digs

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Master Geek

#59940 7-Feb-2007 07:56

Thats sounds interesting...I wouldnt know where to start...

Any chance of a few links to show : how to , where to get them from, prices etc..

grant_k

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#59948 7-Feb-2007 08:57

For the Inverter go to www.dse.co.nz and search for Inverter 300W, you will see 3 options.

One of them is this one which is what I have:
http://www.dse.co.nz/cgi-bin/dse.storefront/en/product/M5211

For the Battery and Charger go to http://www.repco.co.nz/stores/

Buy the biggest Deep Cycle Marine battery you can afford, it will give you the most backup time. The reason for recommending a Deep Cycle Marine battery is that this type are not damaged by running completely flat. Standard Car Batteries are not designed for this, and it will shorten their life.

And then buy a Battery Charger to suit. Probably something with 5 Amp charging capacity would be enough, but check the specification to make sure it can charge up whatever battery you buy in no more than 24 Hours. The CCA capacity of the battery will allow you to calculate this time for any given charger.

Digs

120 posts

Master Geek

#59965 7-Feb-2007 10:42

Ok thanks..

So I price these parts...

So how would it work ?

I would like to put three items on it, ADSL modem, router, and laptop.

Does it know when to automatically switch from wall ( ie normal) power to marine battery power, or is this manual process???

grant_k

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#59968 7-Feb-2007 10:57

Digs: So how would it work ? I would like to put three items on it, ADSL modem, router, and laptop.

With a big battery and the 300W inverter, you should have plenty of capacity for those items.

Digs: Does it know when to automatically switch from wall ( ie normal) power to marine battery power, or is this manual process???

You can switch it manually if you like (by unplugging from wall socket and plugging into inverter), but the best way is to run the equipment from the inverter at all times, then you don't have to worry. If the power goes out, you have many hours endurance before anything dies

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

Digs

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Master Geek

#59972 7-Feb-2007 11:22

Thanks for help..

So setup would be

From the wall socket to the battery system, battery system to the computer equipment.

Gives 12 hours plus protection.

Should I expect a larger power bill for charging having battery system connect 24 hours to the wall socket. Or does re charging only happen when it need to ??

grant_k

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#59975 7-Feb-2007 11:33

Digs: Should I expect a larger power bill for charging having battery system connect 24 hours to the wall socket. Or does re charging only happen when it need to ??

Because mains power is available most of the time, your battery will quickly become fully charged and the charger will just be delivering sufficient power to run your computer equipment i.e. same power consumption as when run directly from the wall socket.

There is one small proviso to that though:

==> No Inverter or Battery Charger or Battery is 100% efficient so there will be a few small losses in the system to pay for

However, you are looking at small change there, probably the same cost as running a 25 or 40Watt light bulb continuously i.e. around $1.30 per week or less.

Probably well worth it for your peace of mind

Digs

120 posts

Master Geek

#59999 7-Feb-2007 13:43

deleted...

Digs

120 posts

Master Geek

#60022 7-Feb-2007 17:35

..."No Inverter or Battery Charger or Battery is 100% efficient so there will be a few small losses in the system to pay for"

So is this 99% or 90% power supply.

Can I expect minutes or seconds power down time for the marine battery idea setup ?

grant_k

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#60033 7-Feb-2007 18:24

NO, no, no Digs, you've got the wrong end of the stick there...

There is NO BREAK at all when the power fails, that is the whole point of running continuously from the inverter/battery.

It is what they call an ON-LINE or NO-BREAK UPS.

80 - 90% is the expected efficiency of this setup, that is due to the losses in the system, but it doesn't mean there is any break when the power fails -- there is ABSOLUTELY NONE!

I hope it all makes sense now.

Cheers,
Grant.

Digs

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Master Geek

#60162 8-Feb-2007 18:42

Thanks heaps...been a great help !

Kezzainc

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#61053 16-Feb-2007 21:52

Keep in mind guys.... Lead batterys smell bad when charging... Needs to be 'outside'

Also check out Jaycar for inverters.

Other than that i feel a router will last weeks on a 550CCA car battery. I do car audio for a living and see 50Amps + been drawn for hours on one battery. A router i dont think could come anywhere near an amp draw. Maybe going on that one can make a power source out of normal AA like batterys to hold it for only a few hours...

UPS would have to be the clean and easy way

grant_k

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#61056 16-Feb-2007 22:44

Kezzainc: Other than that i feel a router will last weeks on a 550CCA car battery. I do car audio for a living and see 50Amps + been drawn for hours on one battery.

A typical car battery has a capacity of between 40 and 65 Amp-Hours. The 550CCA type you mentioned has a 75 Amp-Hour capacity.

Which means that type of battery can sustain a continuous current draw of between 40 Amps (for a small car battery) and 75Amps (550CCA type) for ONE HOUR ONLY!

In the car audio situation, sure you have peaks of 50 Amps on the heavy bass notes, kick drum etc, but the continuous draw is way below that. You need to average out the current draw (using an integration function) in order to calculate an accurate battery life.

Kezzainc: A router i dont think could come anywhere near an amp draw.

That's true. They would typically take a few hundred milliamps. But remember that the OP also wanted to run a laptop which takes a lot more power than a router. My ultra portable draws 3.4A at 19V which is about 65 watts or 5.5Amps at 12V when run through the inverter (plus losses due to inefficiency).

So the current draw for Digs' required setup is likely to be in the vicinity of 6 to 7 Amps I would say which means around 10 Hours endurance with a typical car battery, or maybe up to double that if he gets one of those Deep Cycle Marine batteries I mentioned.

Kezzainc: Maybe going on that one can make a power source out of normal AA like batterys to hold it for only a few hours...

The largest capacity you will find in an AA battery is around 2 Amp-Hours (from one of the NiMH types). If you had a string of 6 batteries (to make 12 volts), it would run the above equipment for 20 minutes at best.