Want to get 12v 2amps from 9v battery. Not sure how to get . Please help

bertus

Joined Apr 5, 2008
21,154
Hello,

It will not be easy, but have a look at the LM5118.
Page 23 shows a schematic that meets your requirements.

Bertus
 

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Thread Starter

nishkum3

Joined Jun 5, 2017
14
Thanks a lot. can I get same from simple pencil battery(AA duracell battery)? if yes,how we can increase the current? pls assist
 

Rahulk70

Joined Dec 16, 2016
511
Hello,

It will not be easy, but have a look at the LM5118.
Page 23 shows a schematic that meets your requirements.

Bertus
I think the OP is referring to a normal 9V 200mAh battery. If he gets an Alkaline or rechargeable one he may be able to get 12V 2A.But wouldn't that kill the battery pretty quickly? Well unless he uses a bunch of them in parallel.
 

Rahulk70

Joined Dec 16, 2016
511
Thanks a lot. can I get same from simple pencil battery(AA duracell battery)? if yes,how we can increase the current? pls assist
Hi,
Most 9V cells are six tiny AAA cells enclosed in that shell. Yes, you could use six AA cells in series to get 9V but if you plan to use 12V at 2A you drain it really fast. You will need higher capacity cells to run for longer duration.
 

Rahulk70

Joined Dec 16, 2016
511
Hello,

When the OP refers to a PP3 battery, it will be drained very fast.
There are other sizes of PP batteries:
https://en.wikipedia.org/wiki/List_of_battery_sizes#PP_series

As there are MANY battery types:
https://en.wikipedia.org/wiki/List_of_battery_types

Bertus
Hi,
I think PP7,PP8 are good choices. Or if size doesn't matter then he could go from a cheap Lead acid to NiMH or Li-ion. If it isn't for a portable project, then nowadays there are those small palm sized 12V 2A LED strip PSUs. They are pretty good in my experience.
 

Rahulk70

Joined Dec 16, 2016
511
12V@2amps is 24Watts, you aren't going to achieve that from a pp3/9 battery,,,
Hi,
Exactly what I meant. It is almost like placing a direct short across the cell. Rechargeable cells are the best option in this case, excluding the AAA and other smaller capacity variants.
 

EM Fields

Joined Jun 8, 2016
583
Want to get 12v 2amps from 9v battery(general purpose battery). Not sure how to get . Please help.
12 volts X 2 amperes = 24 watts.

24 watts / 9 volts ~ 2.7 amperes, so if you had a 9 volt battery with a capacity of, say, 100 milliampere-hours with a 2.7 ampere drain and everything else was perfect, the battery would last for 100mAh / 2700 mA = 0.037 hours = 2.2 minutes.
 

EM Fields

Joined Jun 8, 2016
583
Thanks a lot. can I get same from simple pencil battery(AA duracell battery)? if yes,how we can increase the current? pls assist
Not a good idea.

Since 12volts X 2 amperes is 24 watts, to get 24 watts out of a single 1.5 volt cell would have it deliver 16 amperes into a 94 milliohm load, which would probably blow the cell up.
 

GopherT

Joined Nov 23, 2012
8,012
Want to get 12v 2amps from 9v battery(general purpose battery). Not sure how to get . Please help.
You cannot expect to get 24 watts from a 9v battery (standard transistor radio battery) unless it is for very short pulses and you use a capacitor to help handle thos surges.

One option is to use a standard sized transistor radio battery that uses Lithium chemistry (check eveready and Duracell website) but those may be limited to 2 amps (18 watts) for sustained discharge.

Otherwise, use other types of batteries as mentioned above.
 

Reloadron

Joined Jan 15, 2015
5,781
It all comes down to power expressed in watts. As you see 12 Volts @ 2.0 Amps = 24 Watts. That same 24 Watts @ 9 Volts = 24 / 9 = about 2.7 Amps and as was mentioned, this assumes a perfect world and 100% efficiency in the conversion.

There are DC to DC converters which can be bought as a simple turn key package or you can roll your own but I do not see this happening with a standard 9 volt battery or even six larger 1.5 volt cells. You will need a battery which can supply 9 volts at about 3.0 Amps for an extended period. There is always a trade off.

Here are some examples of off the shelf turn key solutions. Note where they mention efficiency. You would want an MG30 with 9-18 Volts in and 12 volts 2.5 Amp maximum out.

Ron
 
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Thread Starter

nishkum3

Joined Jun 5, 2017
14
Thanks a lot for all the answers. sorry for asking this much basic question.

What i basically want to know that, I want 12v@2amps dc for my device.

*If i will use a 9v dc battery , Will it work for even for quite some time?

* If i will double the battery in parallel then what will happen ? if I will do the same in serial then ? which way will be batter. ?
 

Dodgydave

Joined Jun 22, 2012
9,912
Thanks a lot for all the answers. sorry for asking this much basic question.

What i basically want to know that, I want 12v@2amps dc for my device.

*If i will use a 9v dc battery , Will it work for even for quite some time?

* If i will double the battery in parallel then what will happen ? if I will do the same in serial then ? which way will be batter. ?
If you want 12V, buy a 12V battery try Sla type, easier to charge, and high capacity available.
 

Reloadron

Joined Jan 15, 2015
5,781
I am concern about size as well. So i want the battery as much small ..
If you go back and read post #12 and #13 by EMFields he explains it well. A single 9 volt battery (a PP3 Battery) can only deliver so much current. Even placing two in parallel won't work. The voltage will rapidly drop and your DC to DC converter will shut down. It's a matter of doing the simple math. The smaller the battery the less current it can supply to a load, any load. That is simply how it works. The best solution is a 12 Volt battery and you need 2 Amps.

Ron
 
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