Mike Krzywonski
I need an inverter to plug into the cigarette lighter in a rental car, & will be using it for basic equipment (e.g., laptop, handheld radio, etc.). Is there a recommended wattage I should get?
Dave Marshall
Inverters as a whole are usually constructed as cheaply as possible. Even the nice Black & Decker ones you pay out the nose for really are pretty shoddy. Because of that, I usually recommend people buy an inverter with a sustained power rating (NOT SURGE!) around 50% more than they expect to use on a day to day basis.
This will make sure it doesn't go nuclear on the first blistering hot day when you dive into the car and turn the inverter on without letting it cool down.
The power supplies you'll be plugging in should all have a maximum wattage, or at least the max input voltage and current (simple math). Add up all of the power supplies you expect will be plugged in on an average chase, and multiply that by 1.5.
One other thing to consider is the fact that the cigarette lighter plugs in almost all vehicles max out at 10A (120w). Its a bad idea to run anything beyond a single laptop power supply (and sometimes not even those depending on the size of the laptop!) off of these outlets. When they blow the fuse, they sometimes take unexpected equipment like A/C fans or interior lights with them. That sucks in the middle of a chase, trust me. Inverters really should be hard wired to the battery through a properly selected fuse. If you're absolutely stuck with the cigarette lighter, I'd stay around 300w, and test all your equipment on the inverter BEFORE chasing.
This will make sure it doesn't go nuclear on the first blistering hot day when you dive into the car and turn the inverter on without letting it cool down.
The power supplies you'll be plugging in should all have a maximum wattage, or at least the max input voltage and current (simple math). Add up all of the power supplies you expect will be plugged in on an average chase, and multiply that by 1.5.
One other thing to consider is the fact that the cigarette lighter plugs in almost all vehicles max out at 10A (120w). Its a bad idea to run anything beyond a single laptop power supply (and sometimes not even those depending on the size of the laptop!) off of these outlets. When they blow the fuse, they sometimes take unexpected equipment like A/C fans or interior lights with them. That sucks in the middle of a chase, trust me. Inverters really should be hard wired to the battery through a properly selected fuse. If you're absolutely stuck with the cigarette lighter, I'd stay around 300w, and test all your equipment on the inverter BEFORE chasing.
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Rob Wadsworth
EF5
I have a B&D 400W inverter. Not as nice as the Cobra unit - that is for sure. But it works fine and doesn't overload the fuse for the cigarette lighter plug.
It is enough for my laptop and charging my camera batteries. That is all I use it for anyway, The 2m radio and CB gets power directly from the battery, I don't need more than that - but your mileage may vary.
What may be necessity if you run a lot of gear - something that I haven't done yet - is a better car battery. Like a deep-cell battery, which stores more current and has more on demand w/o overloading the alternator. Of course, it too has its limitations...
It is enough for my laptop and charging my camera batteries. That is all I use it for anyway, The 2m radio and CB gets power directly from the battery, I don't need more than that - but your mileage may vary.
What may be necessity if you run a lot of gear - something that I haven't done yet - is a better car battery. Like a deep-cell battery, which stores more current and has more on demand w/o overloading the alternator. Of course, it too has its limitations...
David Williams
EF4
Hey Mike. I would highly recommend reading over this ST post.
http://www.stormtrack.org/forum/showthread.php?t=13245
http://www.stormtrack.org/forum/showthread.php?t=13245
Joe Dorn
EF2
I have recently rigged two vehicles for amateur radio and extended highway use. The one thing I wanted to get rid of from my previous installations was the inverters, primarily because of the RF noise some of them generate. I found a 12v DC to 19.5V DC power unit for my Dell on, of all places, the Dell site. There are other sources but this was the one I found first and it works. It is about the size of the regular power pack that come with the computer.
I have an extended list of toys in my vehicles but the only one I needed the inverter for was the laptop. I have 12 volt chargers for all of my camera batteries and everything else connects directly into my Anderson Power Pole distribution panel and the panel is double fused to the vehicle battery with HEAVY gage wire. This would not be an option for rental cars.
Beware of cigarette lighter 12 volt sources, they cause unusual problems for the car and the toys. As an example radios with output power of 20 watts or more might turn off due to a voltage drop when you key the transmitter.
Another of my chaser friends had hum getting into his radio transmissions. I had him turn off the inverter and away it went...
BTW, when I was running with inverters, I would charge the laptop battery and then cut the inverter off until the next low battery warning.
The noise generated will vary with different inverters. I have several and one is almost clean, another is an RF disaster. (The clean one could not furnish the power needed for my latest laptop so I had to get a larger one with its noise.)
FWIW...
I have an extended list of toys in my vehicles but the only one I needed the inverter for was the laptop. I have 12 volt chargers for all of my camera batteries and everything else connects directly into my Anderson Power Pole distribution panel and the panel is double fused to the vehicle battery with HEAVY gage wire. This would not be an option for rental cars.
Beware of cigarette lighter 12 volt sources, they cause unusual problems for the car and the toys. As an example radios with output power of 20 watts or more might turn off due to a voltage drop when you key the transmitter.
Another of my chaser friends had hum getting into his radio transmissions. I had him turn off the inverter and away it went...
BTW, when I was running with inverters, I would charge the laptop battery and then cut the inverter off until the next low battery warning.
The noise generated will vary with different inverters. I have several and one is almost clean, another is an RF disaster. (The clean one could not furnish the power needed for my latest laptop so I had to get a larger one with its noise.)
FWIW...
Walt VanRheen
EF1
I chase in rental vehicles as well. I have put together a fused distribution system to all my 12 volt toys. even the laptop uses a 12 to 19 volt power adapter. Why convert DC to AC, only to convert it back to DC, and in the process, create a lot of interference for your phones, radios or video cameras? The best and most efficent way is to keep it DC and keep it properly fused. you need to fuse power at the source and then at the distribution, as well as fuse each leg of the distribution. This is very important. If a power wire leading to your scanner for example is shorted, the fuse on that leg will prevent you from loosing power to other items on the other legs.
http://www.powerwerx.com/product.asp?ProdID=1843&CtgID=1841
http://www.powerwerx.com/product.asp?ProdID=1843&CtgID=1841
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