Overnight inversion

[dguy]

Does anyone have any thoughts or experiences from running a small inverter from a parked car overnight?

We have a road trip coming up, which will likely involve at least one camping stop-over.  The catch...  we need about 8hrs of 120v goodness to recharge the proprietary battery packs in our radios.

Any idea how likely we would be to kill a car battery if for 6-8hrs it was powering a ~100w inverter with a ~1.5a load?   

[aaron88]

A fully charged premium lead acid battery will have a 60 amp/hour rating.  That doesn't mean 60 amps for one hour but instead means 1 amp for 60 hours at full charge when new.  So given that batteries don't charge as well when they get old and your battery will not be fully charged and as you draw more than one amp the charge efficiency goes down, and you are drawing though an inverter which will draw more than it charges, you are probably looking at a 50/50 chance that your car will start in the morning.

Don't worry about it, just be ready to push start your vehicle.

Cheers,

Aaron

.
PS.  There are many things you could spend money on to prevent this but why spend the money.

[dguy]

Don't worry about it, just be ready to push start your vehicle.

That will only work if there's enough juice left to power the car's ECU, I would think.  Though it might work with a flat battery in the Beetle, as its base injection pulse is completely mechanical.  Hmmm...

I've seen some inverters recently with a "low battery protection" feature which claims to shut down before the supply vehicle's battery is to low to start the engine.  Nowhere can I find the manufacturers' definitions of "too low" however.   

... in any case I think I have a solution.  A run-of-the-mill 6v lighter socket adapter and a bit of soldering should allow whomever's in the car to power the communicator from there.  That leaves two battery packs for whomever is on the bike, one of which can be left on a charger in the car during travel.