Additional power for accessories
 

Has anyone here installed additional power sources in their car. I use my cigarette lighter to power my Sat. radio, but also need to recharge my cell phones, maybe get a GPS, too, at some point.

Is there a better way to do this than installing extra cigarette lighters?

yes you have to add a power inverter. If you want it permanent you can hardwire it to the battery. I would install in below the dash away from anything that should not get hot. The inverter will get warm but better be safe than sorry. Yah check ebay for a 300 watt unit this should be just fine for your use. Anything above 300 watts must be connected straight to the battery otherwise you will start to blow fuses. better off you hook it up the the battery any ways. use like 8 gauge wire, you can get it at a local car audio shop and make sure to run a fuse in line about 1-2 feet away from the battery. hope this helps.

Thanks, that's a big help.

If you are going to be running all that stuff, I'd look into an alternator upgrade too. The 115A Bosch unit from the Saab seems to fit fine in the 617 bracket.

Guys, with respect, this is total over-kill for what you need.

The cig lighter circuit is more than enough for satellite radio, GPS and cell charging.....all from the same circuit and then some!

I am doing exactly this and have 3 "in-line" mini fuses all feeding from this circuit. Indiviual fuses ensure that a short on one item does not kill the others. All are fed from the 15 amp original fuse. The added fuses will blow first should there be a short

2 amp fuse for the satellite radio.
2 amp fuse for the GPS
1 amp fuse for the cell charging.

All of this fits behind the center console where I removed the ashtay / cig lighter socket and installed the satellite radio and added a small DC jack for cell charging / MP3 player.

Everything dissapearrs behind the ashtray door in my 97 SL500

Your SL also has a 143A or 150A alt too

not quite sure what your point is????

His total current consumption is a fraction of what the cig lighter alone draws. I think that circuit either has a 10amp or 15 amp fuse.

The alternator suggestion is gross over-kill for this application.

I guess you assume the vehicle is driven with nothing else on or being used. No A/C or heater, aux fan, the blower, headlamps, etc. You can easily exceed the 65A max output of that thing in no time.

Modern sealed batteries charge quite a bit differently than old units.

The added current consumption attributable to the satellite receiver, mp3 player and cell charging is negligible compared to the current consumed by the cigarette lighter......and therefore well within the supply capacity of his (or ANY other factory installed) cig lighter equiped vehicle ......even if he operates the cig lighter at the same time as the other 3 items, I doubt that it will blow the cig lghter circuit fuse. In the event that it does blow, he could simply increase the size of the cig lighter fuse from 10 amps to 15 amps or 15 amps to 20 amps as the case may be without fear. If he is not using the cig lighter at all then this discussion is academic anyway.

now wait, what makes you think that it is ok to put a larger fuse in its place when it was designed for the smaller fuse. Mercedes doesn't put a 15 amp fuse in and expect people to replace it with a 20 amp. Anyways it would be a much nicer install if he went straight to the battery. No extra wire that you can see from the ash tray. I try to keep the car looking original or make it look better. if he now has a wire coming from the ashtray that looks tacky. By no means is it overkill to run 5 feet of wire if that to the battery. and i only suggested that if he get something over 300 watts then he would defiantly have to run the wires. but after thinking it over he should anyways. he wants a permanent feature in the car something that looks decent and extra wire floating around the interior doesn't look good.

Ray is correct, he should have no problem running the cell phone, GPS and radio from the cigarette lighter. All of these items draw next to no power. Don't forget the sattelite radio is just a reciever (no amplifier). I also removed the ashtray in my 123 and hard wired in a 3 outlet adapter. I run my satellite adapter, GPS and cell phone with no problems. Combined they draw less current than using the lighter itself. Now if you're going to be running 4 channels of amps + a subwoofer etc. you might want to run straight off of the battery (don't forget to put a fuse right at the battery connection) and then worry about upgrading the alternator.

1. fractional increase in fuse size - current carrying capacity of the wire used in that circuit or any circuit is rated significanly higher than the fuse size. If you have any knowledge of ohms law, then you wll know that minimizing voltage drop in a circuit is directly related to the resistance of the wire and thus to the size of the conductor. The more current that flows thru a given conductor, the higher the voltage drop....which is not what is wanted by the device being powered. Therefore, increasing the fuse size by the small amount I suggested is not an issue (safety or operational) in THIS specific case. Your suggestion about running a cable straight to the battery REQUIRES a much heavier cable to avoid voltage drop especially if the battery is under the rear seat or in the trunk.....not really an esthetically pleasing thought!

2. I never said anything about wires running out of the ashtray - I said I installed a power jack to be used when needed!

3. You mention "300 watts" which is 20 times what he needs to power the satellite receiver, GPS and cell phone combined. By mentioning "300 watts" you make my case above for much thicker cables going directly to the battery. The cig lighter wire does not go all the way back to the battery....it goes to the (closer) fuse panel (power distribution point) which has its own, much heavier cable going back to the battery. Why are you suggesting 300 watts when he has no need for this amount of power? He specifically mentioned only satellite receiver, GPS and cell phone.

4. I used the word "over-kill" exclusively with respect to the installation of a bigger alternator only - I did not use it in the context you are now referring to. Not wanting to flog a dead horse but I need to repeat this...Adding a larger alternator for the sole purpose of powering his satellite receiver, GPS and cell phone from the factory installed cig lighter circuit is TOTAL OVER-KILL!! The cars battery powers these items NOT the alternator.......which is used exclusively to charge the battery which will be rated anywhere from 60 to 100 amphour or more.

5. As for how you like things to look etc is completely subjective and really has no place in any technical discussion however basic it might be.

I am done with this issue.
Dee8Go is free to decide what he wants to do.
I have only related what I have done in my current car and every car I have owned in the past 40 years.

I'm sorry but i only suggested if he does get something over 300 watts that he would have to run wires to the battery. 300 watts is plenty but for as cheap as it is he should go for it. you never now when this can come in handy.

Okay, I have a small nuclear reactor ordered for my trunk. I think this has ample power to run my low earth orbit satellite communications systems, Loran and GPS devices, 108" HD LCD TV, mobile communications, espresso machine, washer and dryer, and electric fake fireplace, as well as the 1000 watt arena-quality stereo system . . .

Thanks for all of your help.

I just hardwired my Sirius into the power for my stereo. That would free up space for at least one accessory. You Could probably power several things like this.