Boost Converter To Charge Laptop From Car Battery Problem

[Moh001]

I am using 3A boost converter to charge laptop from 12v acid battery, the laptop draws 3amp and the boost converter starts to burn out, what should i add to it to limit the current and protect my laptop?? Resistor capacitor diode???

 

[davenn]

I am using 3A boost converter to charge laptop from 12v acid battery, the laptop draws 3amp and the boost converter starts to burn out, what should i add to it to limit the current and protect my laptop?? Resistor capacitor diode???

you are looking at it the wrong way

you said the laptop needs 3A ... then get a boost converter that can supply at least 3A preferably more 4+ Amps so that the converter
isn't running at its limit

 

[Moh001]

actually the laptop needs at max 1 amp usually it needs 0.5 amp as i measure its original charger, i want to limit the carrent to 0.5 amp, the problem whenever i add any resistor to the out of the boost converter the current stops!!

 

[davenn]

actually the laptop needs at max 1 amp usually it needs 0.5 amp as i measure its original charger,

you very sure about that ??

I haven't seen a laptop produced over the last 10 yrs that doesnt need at least 3A and many up to 5A

what is the make and model of laptop

photo the label on the back of it showing power requirements
also photo the label on the power pack

 

[Moh001]

here is the laptop back and its adapter, the thing is, when i plug it to the laptop and put Ameter in between it reads about 0.5 Amper charging ratio, and when i overuse the laptop it gets up to 1 amp, sidenote ( when i did this measurement, the battery was nearly fully charged)

 

[Audioguru]

The label shows a 19.5VDC/2.31A adapter. It says 45W (19.5V X 2.31A) so the power and current must be when the battery is dead. Your ammeter has some resistance that reduces the current reading.

Either the boost converter cannot produce its rated 3A output without burning or its output voltage is too high causing the current to be too high.

 

[Moh001]

The label shows a 19.5VDC/2.31A adapter. It says 45W (19.5V X 2.31A) so the power and current must be when the battery is dead. Your ammeter has some resistance that reduces the current reading.

Either the boost converter cannot produce its rated 3A output without burning or its output voltage is too high causing the current to be too high.

so what to do? buy 6A boost converter?

 

[Tha fios agaibh]

I am using 3A boost converter to charge laptop from 12v acid battery, the laptop draws 3amp and the boost converter starts to burn out, what should i add to it to limit the current and protect my laptop?? Resistor capacitor diode???

A fuse will limit the current and protect your laptop.
You need to check both the input voltage from the battery and the output voltage from the booster. It should put out 19.5v while the battery side should be at least 12.5v

 

[Audioguru]

I think the cheap (ebay?) "3A" boost converter is actually 0.3A but the dot is so small it cannot be seen.
Please post a video of it smoking and burning.

 

[BobK]

Those cheap boards often require a heat sink added to reach their rated output. Sometimes they even say so.

Bob

 

[Moh001]

thank you all