DIYbanter - View Single Post - trouble with inverter, car battery and car emergency set up

M Philbrook

In article , says...

I had a recent power outage that lasted for 3 days. Not having a
generator on hand, I decided to try using what I did have for short term
power purposes. The items consisted of the car, 500 watt inverter, and
I had an extra car battery available.

I hooked up the inverter directly to the car battery in the car. With
the car running, I was able to run the 46" LCD TV, and a couple of CFL
lights which was all I really needed to do. However, I ran into some
problems. If the car wasn't running the entire time, the items
connected to the inverter would start flickering on and off after a
period of time. If off of the car battery inside the car, this might be
within an hour, but with the separate battery, maybe 10 minutes unless
it was coupled to the car battery in the car with the car running.

All in all, I was disappointed. I'm wondering why the items wouldn't
operate correctly unless the car engine was running. There certainly
wasn't a lot of wattage being drawn.... the TV uses like 100 watts with
the lights maybe 10 watts each, and there were 2. I had hoped to just
use the battery in the car to occasionally "jump" and charge the
separate battery when it got too low, but never got to that point as
the attached items would start flicking on and off.

I see portable power packs with internal battery and inverter at places
like Walmart. The inverter is usually 400 watts or so, so I know this
method should have worked. Any ideas as to why my set up didn't work
well would be welcomed. If it had worked this time, I had planned on
maybe a 1000 watt inverter at some point which I had hoped maybe if this
happened in the future to be able to run the house refrigerator from the
inverter/ car battery set up, but not if I have to have the car running
the entire time.

Thanks for your help.

Pete

A good inverter will shut off to save your battery so you can start the
car later to recharge it.
Thank the those that were thinking in the design.

Jamie