Confused, need basic electrical help

[ccbreder]

I just ran across this on another forum:
"Also, when choosing a fuse, remember that in a DC circuit, using a fuse too close to the expected current load will in effect create a bottleneck in the current (resistance point), which can stress the electrical system, possibly leading to damage to the battery or other sensitive components. "

Meaning if your appliance draws 13 amps, don't use a 15 amp fuse. Use a 20 or 25 amp. Always fuse to protect the wire. thin wire low fuse, heavy wire larger fuse. Always size wire to deliver the amps you need at the distance of the load.

 

[cinemaphonic]

So went to the stereo install place today to talk to them about installing my solar panel and hooking up my house batteries and continuous duty solenoid. They gave me a good quote.

The guy said that I need to make sure that the batteries I get can charge via the alternator. I'm planning on getting the cheapo walmart group 29 deep cycle batteries (2). Does anyone know if these fit that question?

Thanks.

 

[highdesertranger]

I am not saying all, but I have seen many a hacked up wire job from a stereo installer. I wouldn't let a stereo installer install a stereo let alone anything else. I recently posted about maxi fuses on a thread about what type of fuse to use not sure if that's what you are referring to. you should fuse for the wire size which is determined by the current draw/flow. as far as question #2 your voltage regulator in your alternator and your solar controller will take care of the limiting the charge rate, so no need to worry there. if you drill to mount your solenoid just make sure there is nothing on the other side that you would drill into. highdesertranger

 

[SternWake]

Hacks exist in all services.

Him questioning you about the batteries you plan on using is both good, and concerning, depending.

Good because he is aware that some charging voltages might be too high or too low for any given battery, Bad because, if you told him about the flooded group 29's, he shoulda known a flooded battery is pretty flexible in charging voltages.

Where as some AGM's can be limited to 14.4v, and many cars, especially some newer ones, can exceed this.

Question them about the wire they intend on using. Some will use aluminum wire that has a very transparent insulation, for appearance sake, but aluminum wire has to be significantly thicker to have the same ampacity as pure copper. Such insulation is also not rated to withstand oils and grease. Welding wire is nice and flexible but the insulation is not designed to combat oil or solvents and are not fit for long term duty in an engine compartemt

Copper clad aluminum wire is also a popular way to save money , at the cost of voltage drop.
Aluminum wire is also lighter and this is a concern to some who want Boom boom stereos in their faster cars.

You want pure copper. 4gauge or better, 2 gauge, and fuses to protect those thicknesses.