Inverter: continuous power consumption?

**dagnasty** · 01-17-2006, 06:00 PM

Originally Posted by schapman43

A lot of inverters on the market still draw a small amount of power even when switched off. This is why you use a relay.

How is a good way to know if it draws any power? I know that the fan on my inverter is only on when the inverter is switched on and never otherwise.

Sima 300w

**old_lou** · 01-17-2006, 06:21 PM

Originally Posted by dagnasty

How is a good way to know if it draws any power? I know that the fan on my inverter is only on when the inverter is switched on and never otherwise.

Sima 300w

Use a meter in series with the power input and set to measure current. Be carefull as the meter has to be able handle the current drawn by the inverter (if its turned on and under full load) 300(+) watts (input side)= a draw of 300/12 25amp

Uh Uh Uh, You didn't say the magic word !

You can proberly shunt most of thre power with a resistor but its been years since I messed with electronics, ask somebody else about that.

**raucous** · 01-18-2006, 01:57 PM

The ammeter should be in series on the GROUND side of the inverter, not the positive side. Red lead to inverter, black lead to ground.

The inverter should be switched OFF when you do this, as most multimeters can only handle 15 amps before their fuses blow. Besides, you're looking for current draw when OFF, not on.

**g222leav** · 04-20-2006, 09:56 PM

i've searched, and i couldn't find an answer to this question (instead of making a new thread) i thought i'd ask here...

if you properly wire an inverter to the battery and ground it, in addition to using a startup/shutdown controller....would there still be power consumption? (i'm assuming so)

so...if the inverter is continuously draining power, i'd assume installing a relay or a switch would alleviate this...yes?

**nkotch** · 04-20-2006, 10:13 PM

Yea, the whole point of using a relay/switch is cut the battery power going to the inverter when you turn the car off..... All inverters I have seen draw a little power even when off, so cutting the power to it (by a switch/relay) will of course keep it from draining the battery.

**santisurf** · 05-26-2006, 01:50 PM

Originally Posted by nkotch

Yea, the whole point of using a relay/switch is cut the battery power going to the inverter when you turn the car off..... All inverters I have seen draw a little power even when off, so cutting the power to it (by a switch/relay) will of course keep it from draining the battery.

ok so correct me then if im wrong.... i made a little funky diagram

Battery----Block Distributer----Relay Switch-----Inverter---Shutdownand start up controler------CPU
|-------- & Amps-----Speakers

Anyone Agree with me?

also lets post some good Relay Switch and Shutdown and Start up controlers that would be of good use. (for us noobs)

**clever** · 06-22-2008, 06:18 PM

my inverter will arc at the plug some when connected slowly even if its off
from that and several other things i suspect theres a massive capacitor on the input terminals(to filter the power) and the cap draws alot of current when first connected

the cap could continue to draw power even when the switch is 'off'

though i dont think it draws much(on my model) i left a laptop RUNNING on the inverter overnight (cpu idle at 600mhz) and it didnt kill the batery(still started fine)

i should look into loging the current/voltage over time to try and figure out how long it would last, and switch to a dc->dc laptop suply