Hi,
I need a circuit that can give a 12V 2 Amp DC output from 8 to 13 Volt DC
Thanks in advance.

 

Welcome to AAC.

What is the current capacity of the 8-13V Supply ?

 

8-13 Volt is a 55 Ah Lead Acid Battery but it's not in a good well so it's voltage drop to 8 Volt sometimes

 

8V drop in SLA means a bad battery.
It may not supply the current demand.

For what purpose do you need 12V, 2A power ?

I think you are trying to get 12V when the battery drops below 12V, right ?
If this the case, doing it will damage even a good battery.
A 12V SLA should not be allowed to go below around 10.5V.

 

I'm in Syria and we use SLA to lighting a LED when the power outages
but the power is off about 18 hour per day so the battery is go below the 10 V and the LED need a 12 V to be lighting good

 

If that is the case, you need a boost converter which is not easy to make. There are ready made ones.
I think you are better off using a LED CC driver.


That is not the worst case.
If you try to use the battery at 8V to boost it to 12, 2A, the converter will draw atleast 3A. This will further drop the battrey voltage resulting in permanent damage to the battery

 

Thanks a lot my friend, that was very useful to me

 

Hi,
I need a circuit that can give a 12V 2 Amp DC output from 8 to 13 Volt DC
Thanks in advance.

DC to DC Converter. Companies like Cosel USA make them as well as others. Here is an example of a 30 Watt unit which at 12 VDC would be 2.5 Amps.

INPUT
VOLTAGE[V] DC9 - 36
CURRENT[A] 1.40 typ
EFFICIENCY[%] 89 typ


OUTPUT
VOLTAGE[V] 12
CURRENT[A] 2.5

Typical cost is about $60 USD but likely much less expensive units can be had from China.

Ron

 

Hi,
I need a circuit that can give a 12V 2 Amp DC output from 8 to 13 Volt DC
Thanks in advance.

http://www.goldmine-elec-products.com/prodinfo.asp?number=G21500

Would something like this work?

 

I'm in Syria and we use SLA to lighting a LED when the power outages
but the power is off about 18 hour per day so the battery is go below the 10 V and the LED need a 12 V to be lighting good

Unfortunately once you go below ~10 - 10.5 volts over 95% of the batteries charge has already been used up and going any further will start to do damage to the battery unless its a purpose built high discharge cycle rated deep cycle battery.

If you need more run time get a bigger battery because there is nothing to be gained and far more to be lost by taking the battery voltage any lower than 10 volts.

Odds are if you are already running you battery down to below 10 volts on a daily basis you have already damaged it to the point now only holds a fraction (15 - 25 Ah of its original 55 Ah rating) of its original rated charge capacity anyway.