What Gauge Wire for 1A Charging?

[Artric]

I'm going to temporarily put together a makeshift quick charger with parts that I'll need when Mike Dabrowski puts out his DIY kit for the smart charger.

It will charge at 1.05A, and I'd only do this for a couple of hours to give me a decent charge when I can't wait for the slow charger (need to take a second drive and my battery is already dead.

Anyway, I know I'll have to upgrade my fuse to the battery to 2A (currently 1A), but how about the wire, what gauge is needed?

Also considering doing a parallel battery in the future - what gauge is needed for that, and where's the best resource to learn how to set that up?

Thanks,

Art

[Cobb]

14 guage, Wire Size Calculator

Bigger is always better than smaller, but do not take any short cuts.

[Artric]

Thanks for the info - what selections did you make on that chart?

[Cobb]

I picked afew I thought matched your needs. I may use one larger like 12 myself.

I think the reason you regen isnt showing with the key on is the fact the charge is too small or low to register.

[Artric]

Originally Posted by Cobb

14 guage, Wire Size Calculator

Bigger is always better than smaller, but do not take any short cuts.

I actually just came back and played with that chart, and the absolute smallest it will give you is 14. I'd really like to know what the max you can run through 18 gauge is... so I can continue to use my fancy power supply wiring and molex connectors.

Anyone know the formula?

I assume we'd measure from where the wire exits the grid charger circuit. I wonder how long that is down from the left hand side of the battery compartment, through one of the bottom holes, and up to the battery? Guess I'll have to measure the next time I get the lid off.

[Cobb]

Interesting... Maybe its using my rule of thumb that lower numbers, bigger wire is better?

Yeah, I can see the fine print now. May be warm to the touch, wire will vanish in a magic cloud of smoke if used in 80+ ambient temperatures.

Using wire too small may make your nick name the Prince of Darkness, Joseph Lucas.

[MN Driver]

FYI, I played for that circuit calculator and it really is designed with 120 volt AC in mind. Everything that I put in, even putting in 1 amp or 0 amps going all the way up into quite a bit bigger numbers came up with a 14 gauge as the smallest wire.

I've used 22 gauge with 7 amps before I had 12 volts drop to 10 volts on the other side. The wire was hot but I've used 22 gauge for quite a long time with that exact load. It's NOT something I would do in a car because I was always around it, it was risking, indoors, but I was next to it 100% of the time, fused circuits, etc.

For 1 amp charging in a car, it won't take much but I'm inclined to tell you not to use anything too small, always use copper wiring in a car due to the nature of abrading insulators causing serious issues. Always use a fuse and keep wire lengths in the safest and shortest paths possible but making sure that any sharp edges are smooth and that the wires are setup so they aren't rubbing while the car shakes. Make sure that any connections are secure, be very careful with soldered connections because that is a connection that is loose and flexible directly next to a solid one which can break your connection over time with the wiggling. I prefer to use automotive grade splices and crimps with built in strain reliefs. The connections to the radio in my Prizm that I installed by soldering in an adapter so I could plug and play the a new stereo head unit, it slowly developed loose connections and I'd lose a speaker connection from the head unit after a year followed by having issues with the circuit that controlled the lighting when it was turned off. It looks cheap and as if it is the wrong way but I'm convinced those little plastic crimp connections are the way to go.

I don't know the ideal wire sizes to use but I don't see 18 gauge wire being a problem for 1 amp, don't forget your fuses.

[JimIsbell]

I discharge mine through 18 ga with 7 amps. (printer cable) Only thing that gets hot is the alligator clip

[Artric]

Originally Posted by JimIsbell

I discharge mine through 18 ga with 7 amps. (printer cable) Only thing that gets hot is the alligator clip

Just wanted to say thanks for the info! Maybe I don't need fancy wiring at this point after all. I'll try with the wiring that I have (replacing the existing fuse & diodes) and monitor it carefully.

That said, I hope to get around to putting time in assembling my "quick lunch box charger" today!

[JimIsbell]

Remember, I was talking about CHARGING through a printer cable. It works for me, but your mileage may vary. Also, dont try to discharge through light wire if you are using a CBA or other battery analyzer. I just did that using my terminal board modifications. The small wire and the 3 (THREE!) screw connections and two alligator clip connections, ALL the connectors and the small wire runs drop voltage so the analyzer showed the curve to be 1.5 volts lower than when discharging through the huge screw terminals on the ends of the sticks. I was discharging at 6 amps and it hit 5.4 volts in just 10 minutes because of the voltage drops. At first I thought the battery was kaput but I couldn't figure out how all 20 sticks would go bad at the same time. Then I analyzed the situation and could see where all the voltage was lost.