# Using 220v inverter from 48V battery

Discussion in 'Power Electronics' started by NVZN, Dec 28, 2016.

1. ### NVZN

31
0
Dec 17, 2016
Hello,
I have :

-48V LiFePo4 Battery (max volt is 54.6V)

-200W 15A DC Buck converter 8-60V to 1-35V adjustable

- a power outlet car socket 12V 120W

-Paco 150W Power Inverter 12VDC to 220Vac

Does it work if i :
Connect the 48v battery to step down converters,

Set the converter out put 12v,

Then connect to the inverter.

Questions :
1.The car socket positive pole is on the center tip, right?

2.I heard the car socket polarity negatively earthed, (so it means there is ov negatives?) so would it do damage or dangerous if i connect to a 12V output converter?

Im kinda new about negatively earthed thing...
Here is the inverter notes

Notes :

I only use it when in emergency, morelike blackouts or going outside but need electricity.

2. ### Harald KappModeratorModerator

12,454
2,984
Nov 17, 2011
This should work, but is terribly inefficient as you have losses in both the step-down converter and the inverter. It would be much better to generate the 220 V AC directly from the 48 V.
In your application (emergency only) it should be viable, though.

3. ### NVZN

31
0
Dec 17, 2016
oh yeah i know about efficiency.

hmm, where i should connect the polarity?

is it right car sockets positive pole is on center tip?

what about negatively earthed? what it does mean? will it damage my inverter if i connect + - power sources?

4. ### Harald KappModeratorModerator

12,454
2,984
Nov 17, 2011
The typical connection is:
tip = +12V
outer contact = 0 V (ground)
It means chassis = 0 V = ground = earth = negaitve pole of the battery ... different expressions meaning all the same.
You connect '-' to '-', '+' to '' and everything should be o.k.

Before making the actual connections check the carpower system's polarity. Battery '-' should be connected to chassis, then you're fine.

5. ### Colin Mitchell

1,416
314
Aug 31, 2014
12v batteries are so cheap that you should use only a 12v battery.
150 watt is more than 10 amps and you will need a 60 amp-hour battery. This is a car-battery and a half.