Inverter question

[Dbraw]

I just noticed an ad from Lowes that had a couple of inverters for $24 and $29 listed. They both plug into a cigarette lighter bracket and convert 12 volt to 110. Could these be used for a short period of time to make coffee or some similar function while boondocking? How much would they draw down the house battery?
Dan

[mcneon]

Dan, I'm afraid you won't get nearly enough 110 volt power from one of these to run a coffeemaker. You're limited by the amount of current you can draw from the cigarette lighter socket, which is usually 20 amps. That gives a practical limit of around 250 watts.

My coffeemaker is 800 watts and draws 70 amps from the batteries. To provide that level of power, you need a higher-power inverter, heavy battery cables and, ideally, lots of house battery capacity to draw from.

Bob McKeown
Nashville

[RoadKingMoe]

The cigarette lighter outlets that are part of the plate with the TV hookups are only rated for 8A or about 100W. Winegard warns of them melting at higher current. You can use them for a small inverter to power a low wattage electronic device such as a small TV and satellite receiver.

[donnall]

I got an inverter yesterday at OfficeMax for only $9.99 (after $10 rebate) although it won't handle a coffey maker it should be great for recharging my camera batteries, Lap Top, and stuff like that.

Don

[Dbraw]

Thanks to all for the ionformation. If it wasn't for this Forum, I would still be trying to figure out how to open the door on our Airstream.
Dan

[ALANSD]

I bought my inverter (a jensen) new off EBAY for 15 bucks. It handles two good sized appliances at a time. We use it to run the TV and Video games when on the road without the generator running. There are often good deals on them there.

[casarodante]

This looks like a good place to ask this question.

Picked up a cheap inverter that says it does 350 watts. I have a TV and sat receiver that I want to be able to power. According to my Kill-a-watt monitor, the TV does 40-45 watts and the sat receiver does 11. What else should I be looking at? Amps, etc?

I am not looking to power my microwave, just some small convenience items. What is the estimation on power drain on the battery? Is there a link that spells this all out?

Thanks for the help!

Roger

[71_safari]

Hi Roger,

Well good for you for actually using the KillAWatt instead of guessing. It must be a flat screen tv as 45 watts would be low for a conventional tv unless it is really small. Anyway, if your load is roughly 60 watts total, that would be .5 amp at 120 VAC, or 5 amps at 12 volts which is what your power source is (Ohm's Law, V x A=W). However the inverter has some losses, especially a cheap one. Say 20% or so and you have a total load from your 12V house battery of about 6 amps.

You then need to find the total rating of your house battery, but if you have 2 house batteries, each with a 60 amp/hour rating at 12 volts, you have 120 amp/hrs of capacity. That is roughly 120 amps for one hour, or 1 amp for 120 hrs, or anything in between. You don't want to drain them below 50% or it negatively impacts the life of the battery. So you have a useable 60 amp/hrs capacity, which is 10 hrs, with a 6 amp load. Assuming no other loads.

Hope that helps.

-john