Can I charge 12v battery with a 12v power supply?

[Chris142]

I have a 12v automotive battery. If it got drained can I recharge it wirh a 12v Power supply? The power supply actully puts out 13.2~ volts and 5A.

I know that an actual battery charger will taper off as the battery becomes fully charged and I assume the Power supply wont?

I'm running a high power CB type of radio and the 5w power supply won't run the radio. I can use a 12v battery untill it runs down.

 

[Carbon]

No. If the supply put out 13.8 volts, you could.

 

[JHZR2]

If you are actually forcing current in, the battery will go into thermal runaway and burn up.

If the power supply will provide up to a certain amount, then it should be OK.

Need to measure current as voltage goes up and stays at 13.2V.

 

[spackard]

I use two 6V SLA batteries and a PowerSonic SLA charger as an UPS for some emergency radios. The batteries filter out all the A/C ripple from the charger.

You can pick up a 13.8V 10A power supply on ebay for about $50 including shipping, and run the radio direct.

 

[1 FMF]

Originally Posted By: Chris142
I have a 12v automotive battery. If it got drained can I recharge it wirh a 12v Power supply? The power supply actully puts out 13.2~ volts and 5A.

I know that an actual battery charger will taper off as the battery becomes fully charged and I assume the Power supply wont?

I'm running a high power CB type of radio and the 5w power supply won't run the radio. I can use a 12v battery untill it runs down.


not sure what you are actually doing or trying to accomplish.
if you want to charge a 12 volt lead-acid car battery with a 12 volt DC power supply which is not a battery charger, then no that won't work. A car battery at full charge is 12.65 volts. And the battery at 12.25 volts open circuit voltage is down around 25% charge which is basically dead, so if you have a 12 volt power supply that puts out only 12 volts, then it would not work. Then you mention the power supply actually puts out 13.2 volts- if that is the case then it could work, however if the battery is not near full charge then the battery's internal resistance will be verty low and allow for high current flow out of the power supply, well over 5 amps, which would burn out the power supply. There is a different between "power supply" and "battery charger". A battery charger will have a current limiter in it to prevent this from happening, whereas a DC power supply most likely would not.

 

[Chris142]

Originally Posted By: spackard
I use two 6V SLA batteries and a PowerSonic SLA charger as an UPS for some emergency radios. The batteries filter out all the A/C ripple from the charger.

You can pick up a 13.8V 10A power supply on ebay for about $50 including shipping, and run the radio direct.
I need a 20a power supply for this monster. Right now the power supply is at 13.8v. I will bring my real charger in tomorrow

 

[meep]

you can do it. depending on battery SOC and power supply type it might work, might not, might burn out the PS., or it could be fine.

 

[brianl703]

I've done this before and it works fine if the power supply is a linear power supply (if it's heavy, with a large transformer inside, it's a linear power supply). With those, the output voltage drops as the load increases, so a discharged battery will not be getting a full 13.2V, but the output voltage will reach 13.2V as the battery charges.

Also, those power supplies typically have a regulator board inside that has a voltage adjustment control so you can increase it's voltage to 13.8V for better charging.

 

[nikorasu]

What type of CB are you running that it needs more than a 5 amp powersupply?

Anyways just use a 2/4/6 amp battery charger, should cost $25 or so. The radio will pull amperage from the battery when you transmit. Otherwise the charger will charge the battery and run the radio as a reciever.

 

[PandaBear]

If you are talking about low quality non switching power supply (the one that only support 110V or 220V but not both), they are very likely not rated at 12V.

I've seen some 6V power supply outputting 9V at open circuit and some 12V power supply outputting 18V. Just right for some intellectual misuse for another appliance, but not for charging a battery.

 

[ATS-V]

I use old DC power supplies (like old phone chargers) that put out about 13v and 500-750ma to trickle charge my tractor battery during the off season. When the batter voltage drops a little (once a month) then I hook up the "charger" for a day or two until proper voltage is reached. YMMV

 

[QuadDriver]

Originally Posted By: Chris142
I have a 12v automotive battery. If it got drained can I recharge it wirh a 12v Power supply? The power supply actully puts out 13.2~ volts and 5A.

I know that an actual battery charger will taper off as the battery becomes fully charged and I assume the Power supply wont?

I'm running a high power CB type of radio and the 5w power supply won't run the radio. I can use a 12v battery untill it runs down.


not enuf volty thingies.

 

[Eddie]

13.2 IS TO LOW. Idealy you need 14.4-14.6v.

 

[brianl703]

It'll charge with 13.2V, it will just take a long time. 13.2V is often used as a float charge voltage.