how to use pc power supply to charge 40A Battery ?

[tpetar]

Re: how to use pc power supply to charge 40A Batter ?

I'd say it's not safe and a bit unpractical to charge a battery with a modified computer power supply. No one here has even bothered to ask what kind of battery he is attempting to recharge.

Yes, in fact, that's the point, we should give our suggestions to thread starter, with the aim to improve thinking about this battery charging needs. I completely agree with quoted Steinar96 post #20. People sometimes dont know what design to choose, exposing themselves to unnecessary risk to waste time, money and sometimes like in this creating a dangerous situation for the outbreak of fire or similar things.

 

[jeffrey samuel]

Re: how to use pc power supply to charge 40A Batter ?

I was able to pick what he meant and was right on my assumption.

not everybody is like you most wise one if the poster had the post topic ight this would have been solved easily

- - - Updated - - -

I was able to pick what he meant and was right on my assumption.

not everybody is like you most wise one if the poster had the post topic ight this would have been solved easily

- - - Updated - - -

hi,
to modify pc PSU you need to search a voltage divider around the 12 v output (or 5 v output). This voltage divider feeds some voltage beck to an IC placed somewhere close to the region you searched. By modifying the values of the resistors of the divider you can go up to 14 V if the unit does not have an over voltage protection stage (if it has, you have to deactivate it ... it is better to get an other pc psu without that...).
Be careful when modifying the resistors from the voltage divider, if open loop appears between output of the divider and the supply of the divider (i mean the superior resistor), risc of electric shock may appear (the Ic which get's the voltage signal thru this voltage divider from the output of the PSU, does not see the output voltage anymore -doe to the open loop-, and gives high gain to its next stage ..............beside the voltage regulator loop it may have a current regulator loop to..........)
About the charging current it is about ~ 4 A .
A safe alternative would be to make a traditional battery charger with transformer ..... it cost's a little, it's heavy but work's fine . The pc PSU is a cheap alternative ( I use it to :wink: ) , and you need to take care of the charging current, if to high , the PSU can deactivate (the cooler stops) It is indicated to measure that current to get an idea about the status of your battery.....

safe enough to blow your roof tops up what are you planning to do cause a mini land slide over your house

 

[Raza]

Re: how to use pc power supply to charge 40A Batter ?

@tpetar

You want to say you know from begining that 40A is 40Ah, and that 40A is not current of charging ?

Yes you are right.

I always mean that Ah is battery capacity and A is current flow.

You are right on your meanings but in the area he is from I know the general people or market language.

 

[jeffrey samuel]

Re: how to use pc power supply to charge 40A Batter ?

@tpetar

Yes you are right.


You are right on your meanings but in the area he is from I know the general people or market language.

that proves your epertise then have to leave it as such

 

[janosandi]

Re: how to use pc power supply to charge 40A Batter ?

thx for ur replys i've changed the resistor from 12v to tl494 which control voltage & i have14 v now but need someway to limit the current

 

[zsolt1]

Re: how to use pc power supply to charge 40A Batter ?

thx for ur replys i've changed the resistor from 12v to tl494 which control voltage & i have14 v now but need someway to limit the current

try to use the protections you have in the psu,It depends from it's structure. You can search for a low value resistor (0.xx ohm/1 W ) in the scheme of the psu, and try increasing it's value. (also in the output region). Usually current is sensed by a voltage drop on a low value resistor in this type of psu. Measure the current taken from the battery when you cuple the psu. If the current is to high the battery may be defect. Search on google about the charging current of your battery.

Ps : keep pioneering ;-)