12V power supply vs 12V battery charger

Thread Starter

Chassis

Joined Apr 21, 2015
6
I am trieng to figure out the difference between a 12V power supply and a 12V lead acid battery charger. Can a power supply be used as a car Battery charger aswell or can somone please explain to me the difference.
 

Alec_t

Joined Sep 17, 2013
14,337
A charger needs to provide a controlled voltage higher than the battery voltage in order to charge it, and also needs to control charging current. Its voltage needs to change as charging progresses.
A 12V power supply will provide a constant 12V, and may or may not have a current limit/control feature.
 

wmodavis

Joined Oct 23, 2010
739
A float charger for a lead acid battery is a constant voltage device and a regulated power supply is ideal for that.
Must set the voltage at optimum value depending on designated battery use and/or manufactures recommendation.
 

alfacliff

Joined Dec 13, 2013
2,458
most "12" volt supplies are actualy 13.6 volts to operate car stuff, 13.8 is the normal engine running, car voltage and will charge lead acid batteries. the majority of battery chargers have no current limitting other than maybe a fuse., chargers are also not known for having good filtering, so they make lousy supplys for testing equipment.
 

gerty

Joined Aug 30, 2007
1,305
And if you're thinking of using a car charger for a power supply be advised most of the newer ones have a circuit built into it that requires you to connect to a battery before it'll turn on. The purpose of that is to prevent you from connecting it backwards(reverse polarity) and blowing something up. Yes the circuit can be bypassed ..
 

EmAv6

Joined Oct 10, 2017
1
I am trieng to figure out the difference between a 12V power supply and a 12V lead acid battery charger. Can a power supply be used as a car Battery charger aswell or can somone please explain to me the difference.

I am trying to figure out the same difference.
I got an amp meter with Bluetooth connection (only need s 12v to work) but when connected to the car battery the screen keeps flashing like there isn't enough power (battery shows 12.5v - 13.1v), but when i use a 220v ac to 12v dc adaptor it works perfect

I have been trying to figure out the difference so i can get it to work from the battery only.

Anybody know why this is happening?
 
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