Can I make a dsl modem work with battery?

hi there,

As with all of you i am facing the same problem of power failure / power loading shedding (one hour on and one hour off) and therefore it is diffcult to work online without a generator or a ups which i cant afford right now.

So here comes the query.

Can I make a dsl modem work on a battery

I have a dsl modem 9V and 0.5A.

What i am planning to do is to replace my emergency light's battery with a 9V battery ( the emergency light's battery is currently of 6V). I have to also change the tubes of emergency lights to 9V if i want to use both the tubes or one tube if i am not using the modem (right?).

The emergency light has got the charger builtin so i am supposing that it will charge the 9V battery as well (right?)

Its simple to take out two wires from the battery and plug it in the modem making it uninterubted. The only thing which i cant understand is that

Should i have to get a battery whoz initial current is 0.5A?

whats this 0.5 A thing on the modem?

Also please inform if 9V 4.5AH battery is good enough for one hour back up if fully charged or should i go for a higher AH battery.

I am a noob in this thing so am am stuckup with the 0.5A thingy??

The battery which i already have in my emergency light states

6V 4.5AH Maintainance free lead acid battey.

Standby use 6.75- 6.90 V

Cycle use 7.20 - 7.50 V

Initial current: less than 1.35A

so i suppose that the replacement battery should be like this

9V 4.5AH or higher Maintainance free lead acid battey.

Standby use 9.75- 9.90 V (dont know what it is)

Cycle use 10.20 - 10.50 V ( dont know what the hell is this too)

Initial current: less than or equal to 0.5A ?? (is it so)

Also i guess i have to search for the tubes which i will replace in the emergency light with 9V and 0.5A current. (Confused about this too)

I am using a laptop which gives me a good backup of 2 hours with an hour of charging.

I want to do uninterupted work and without installing ups as i do not have a budget for that.

Please advice what to do?? (what specs battery to buy)

[quote=", post:, topic:"]

Can I make a dsl modem work on a battery

[/quote]

Yes.

[quote=", post:, topic:"]

I have a dsl modem 9V and 0.5A.

[/quote]

That amounts to 4.5 Watts.

[quote=", post:, topic:"]
What i am planning to do is to replace my emergency light’s battery with a 9V battery ( the emergency light’s battery is currently of 6V). I have to also change the tubes of emergency lights to 9V if i want to use both the tubes or one tube if i am not using the modem (right?).

The emergency light has got the charger builtin so i am supposing that it will charge the 9V battery as well (right?)

[/quote]

Don’t do that. Using a 6V circuit with a 9V battery may permanently damage it. Get a new 9V battery for the modem. The charger for the tube is regulated and rated for the 6V battery. It will not charge the 9V battery properly.

[quote=", post:, topic:"]
Its simple to take out two wires from the battery and plug it in the modem making it uninterubted. The only thing which i cant understand is that
[/quote]

It’s not that simple.You have to regulate the voltage from the battery.Too high a voltage from the battery might damage the modem. Too low a voltage might damage the battery. You need a circuit for voltage cutoff if it decreases beneath a certain limit which depends on the battery in use.

[quote=", post:, topic:"]
Should i have to get a battery whoz initial current is 0.5A?
[/quote]

You need to consider the batteries current capacity. 0.5A continuous current means that it consumes 0.5 Amperes per hour. A battery rated at 4.5AH will last you about 8-9 hours, ignoring various other loses.

[quote=", post:, topic:"]
whats this 0.5 A thing on the modem?
[/quote]

It is most likely the continuous current requirement for the modem.

[quote=", post:, topic:"]
Also please inform if 9V 4.5AH battery is good enough for one hour back up if fully charged or should i go for a higher AH battery.
[/quote]

It is more than good enough provided an appropriate efficient circuit is used.

[quote=", post:, topic:"]
I am a noob in this thing so am am stuckup with the 0.5A thingy??
[/quote]

Get a cheap low wattage inverter for use with a 12V battery.

[quote=", post:, topic:"]
The battery which i already have in my emergency light states

6V 4.5AH Maintainance free lead acid battey.

Standby use 6.75- 6.90 V

Cycle use 7.20 - 7.50 V

Initial current: less than 1.35A

so i suppose that the replacement battery should be like this

9V 4.5AH or higher Maintainance free lead acid battey.

Standby use 9.75- 9.90 V (dont know what it is)

Cycle use 10.20 - 10.50 V ( dont know what the hell is this too)

Initial current: less than or equal to 0.5A ?? (is it so)


Also i guess i have to search for the tubes which i will replace in the emergency light with 9V and 0.5A current. (Confused about this too)

[/quote]

Initial current is the initial charging current which is safe for the battery. Exceeding it will damage the battery. This varies from battery to battery.

[quote=", post:, topic:"]
I am using a laptop which gives me a good backup of 2 hours with an hour of charging.

I want to do uninterupted work and without installing ups as i do not have a budget for that.

Please advice what to do?? (what specs battery to buy)

[/quote]

Start saving money for a UPS. Tinkering yourself will result in damage to your equipment since you clearly have no idea what you are doing (or even what you are trying to do).

Dear Asad,

Really thankful for your clarification and i got some understanding of what you are saying. Since i am not in a position to spend about 14K on UPS and battery for the time being i will contact some electronic shop and ask them to make me a 9V rechargable battey with a steady/ continous current of 9V no matter if the 12v battery is fully low or fully charged.

I will make sure they use the 12V battery and an IC (i guess) to make the 9V steady current. Also i got to know the thing 0.5A which was bugging me.

Thanks for explaining the things in detail.

Regards,

YASIR

A good quality APC UPS costs 6-8K and can easily run your router/modem for more than an hour, considering it can power the entire PC for 15-30 minutes. If you don't use it with a PC but instead with the router/modem only, it will last much longer.

asad!

Dont u think its a wastage of energy?

Firstly converting from dc to ac and then again from ac to dc.

I have checked some ups which are in my affordability range with 4ah battery will hardly work for 45 to 50 min on modem and the battery will be fully discharged.

I dont think that in another hour it will be charged fully.

I m in lahore and power goes after every 1 hour.

Some energy is wasted but that is always the case anyway.

The conversion is from AC to DC and back to AC. You plug your router's adapter in the UPS so you could say that the adapter converts the UPS' AC output again into DC.

What load values are you using to calculate the 40-50minutes period?

sorry for a later reply i was not here for two days.

i do not know the exact conversion thingy but the guy who was selling the ups converted it with regards to 65ma input and 500ma output.

he said it will give u a 45mins back up.

according to my calculation if its right it will give 61 minutes if fully charged.

asad !!! u there?

and how about this one??

http://www.mustek.de/eng_/html/produkte/PowerMust636.htm

also can i connect wet battery of 108 amp with it if i wana use a pc as well?? will it charge the battery over night fully??

[quote=", post:, topic:"]

sorry for a later reply i was not here for two days.

i do not know the exact conversion thingy but the guy who was selling the ups converted it with regards to 65ma input and 500ma output.

he said it will give u a 45mins back up.

[/quote]

500mA output? 65mA input only? Even my PC pulls 6-7 Amps at least when running on UPS. The figures you provided do not seem right…

Ask around for price of the following models:

APC Back-UPS CS 500VA

APC Back-UPS CS 650VA

They should be in the range of 6K to 8.5K depending on where you inquire. These will last more than an hour for both your laptop and router/modem.

hi asad,

have you heard about a bus powered DSL modem?

If i can get one in Pakistan i can connect it with laptop and here i go with uninterupted work with no maintaince.

Here is the link which i found after some research.

http://www.usr.com/support/8500/8500-ug/index.htm

thats a us robotics adsl modem which gets power from usb of computer or laptop.

USB ADSL modems? Those are available in Pakistan. I first got a Speedtouch USB model when I got DSL from Micronet. They have very very basic features and no firewall. They can be used but keep in mind that they have very little routing capabilities.