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Would this Battery charger work as a direct power source?

  1. Aug 28, 2014 #1

    I need a source to power ADSL router when the electric power would be cut for any reason because i need to keep my laptop that i use for work connected to the internet.

    I found this "Anker® 2nd Gen Astro Pro2 20000mAh 4-Port Aluminum Portable External Battery Charger with 9V/12V Multi-Voltage Port and PowerIQ Technology"


    My question is:

    can the 12V port for this charger work as a direct power source for the router instead of its regular 12V 0.7A power adaptor?
    and if yes how much time the battery could last before the need to be recharged?

  2. jcsd
  3. Aug 28, 2014 #2
    You should post the specific router model and hardware specs. This would allow us to know the router's power requirements and be able to answer your question better.

    Edit: I missed the part where you gave the 12V/.7A rating. Sorry about that.

    A rating of 20000mA-hr (20A-hr) suggests that the battery could supply a current of 20A at 12V for approximately 1 hour. If you are only drawing .7A (and not 20A), then you should obviously be able to supply current for longer than 1 hour.

    Doing a little bit of unit analysis:

    20A-Hr/.7A = ~28.5 Hours
    Last edited: Aug 28, 2014
  4. Aug 28, 2014 #3
    If the supply is 12vdc at .7A then the 20000mAh 12vdc battery should last about a day or two depending on actual load. Sometimes the little wall wart supplies are ac to ac. You may be better served by a UPS.
  5. Aug 31, 2014 #4
    The last post from montoyas7940 and his suggestion would serve you best. Since your router draws such a small amount of power, just get a small UPS and plug the router supply into it. This way, you don't have to worry about the router needing AC or DC, and voltage concerns. A UPS rated at 200VA or more would handle the router and allow it to operate for some time without 110 VAC line power. I think you could locate something cheap that would meet your needs very well (see this URL for an example).

    Last edited: Aug 31, 2014
  6. Aug 31, 2014 #5
    Thank you for the replies and the advice about the UPS , here's some more details:

    I have been using Ideal 5310ALU UPS 1000VA (http://www.idealups.com.tw/product_ny2_3.html) to power both the router and an extra 19" LED screen connected to the laptop, and it used to be able to handle them both for almost 2 up to 3 hours when it was new , but now (after 16 month) it hardly handle the router for 25 or 30 mins max!

    so, I thought maybe i'd try another thing and this "External Battery Charger" seems to be good solution if it'd work because its weight is much lighter and it costs less than the UPS.
  7. Sep 1, 2014 #6
    The problem with your original UPS is its battery. Most UPS devices use a lead-acid battery and a lot of them undersize the battery, meaning that it undergoes a significant discharge at high current each time it's called upon to do its job. That current can be significantly higher than what the battery was designed for (particularly for extended or continuous draw). Deep discharge and over-current are two factors which lead to a reduction in lead acid battery capacity and eventual failure, so it would be expected to see the type of capacity loss you described. Typical small-scale UPS devices are not intended to act as a battery power supply for extended operation, but only a back-up, used for short intervals.

    I can't recommend the approach you're suggesting (and at $80, it appears more costly than a small UPS), but if you feel the experiment warranted, it can prove to be a learning tool for you. However, you're really accomplishing no more than what your UPS originally did for you, and the money might be better spent in purchasing a new battery for your UPS.

    As a side note, you can use a larger (higher capacity) battery outside your UPS to gain a longer back-up interval. That battery would substitute for the internal smaller battery. Just be sure to read up on battery safety, and you might want to construct a small enclosure for any external battery just to be on the safe side.
  8. Sep 1, 2014 #7
    I would try a higher capacity deep cycle for the UPS. Use the old one as a core trade in at Wally world (they don't care about size) and wire a big one externally. And I second the vote for battery safety mentioned by RBTO.
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