Is 5v to 12v converter safe
Yes, DC/DC step-up (boost) converters are safe. You'll need to look at current, efficiency and noise.
What happens if I use a 5V adapter on a 12V device
That said, I'd suggest against using a 5 volt supply for a 12 volt device. For a start, if it really requires 2 volts (or close to it), you will have a problem because 12 x 2 = 24 watts, while 5 x 2 = 10 watts, so the power supply is under-specced to do the job at maximum load.
Can I use 5V charger for 12V
Generally no as you need more volts in the charger to overcome the volts in the battery. However, if the battery cells terminate at the battery connections so that the individual cell voltage is less that 12v.
Can I use a 5V adapter to a 12V object and work
Most likely not. But as always it depends on what product you are trying to power up with the 5V instead of a 12V source. A fan may work but slow, a heater will work but at 17% power output, a peltier cooler/heater will work but will not remove as much heat.
Can you charge 12V with 5V charger
No way it'll do 12V or any other chemistry. To charge any battery, you need to give it a voltage higher than what it's going to charge to.
Can I connect 5V to 12V
Conclusion. Long story short, you should avoid using a 12V power supply on a 5V device. Unless there is a protective measure in the device to tackle the resultant surge of current, it is best to avoid using a higher voltage than the maximum rated voltage.
Will 12V work on 5V
Long story short, you should avoid using a 12V power supply on a 5V device. Unless there is a protective measure in the device to tackle the resultant surge of current, it is best to avoid using a higher voltage than the maximum rated voltage.
