a lot of varibles but......
 

I would like input on the time you could run a v6 dodge engine on battery alone. Ive been thru a few alternators and donot want to buy another. I keep the battery (new this year) topped off in the garage.
I also have 80 w solar on the roof the was used to supply an aux battery. the aux battery was connected to a cigg plug n used for charging laptop, shaver, etc. I was wontering if i could connect it via two male cigg plugs via a always hot female cigg plug with, gosh, some small wire prob 16/18 gage.
If that arrangment is feasible would i need to disconnect it during start?
No running lights and working on a disconnect on brake lites..
Also have a scangage II to moniter water temp and batt voltage and will prob disconnect the radiator fan ( especially now for winter n east TN)
Again i know theres alot of varibles but just starting to compile figures to determine the range. thanks n advance. porgie

Depends on running load and battery capacity. 50 amp load on a 50 ah battery gives you about 40 minutes until the voltage sensitive stuff shuts off. Same load on a 200ah battery gives you about 3 1/2 hours. On my twin 200's in the F250 diesel, I got 6 starts with glowplugs and fuel heaters, headlights and running about 45 minutes before I realized it wasnt charging. No idea about load other than the glowplugs are 90 amps for 2 minutes and the starter uses about 300 amps

16 ga wire is good for 15 amps in household service. If current is higher than that, expect meltification. Dash wiring may not be that big gauge

You'll need to measure the load on the battery during normal driving to get a sense for what the running requirements are.

I started to measure various electrical loads on my vehicles but only got as far as my Acura. It has a minimum running requirement of 163 watts. I listed all the loads in this spreadsheet under the TSX tab.
https://docs.google.com/spreadsheets...it?usp=sharing

You're going to kill batteries much more quickly, especially if they aren't deep cycle.

You'll want to change out all the lights to LED if you want to get very far at night.

the batt is a h7 94r and has around 80 ah capacity. Starting from home i will start with a starter/charger.
Please give me your input on tieing in the 80 w solar panals via the thin wire via cigg plug thats hot all the time. Should i disconnect that panal for startup or would it matter.
Again, thanks for the reply: Piotrsko

Can i use voltage drop over 1/2 hr ( its equiped with scangageII) to determine the AH load?
again, thx redpoint5

Just to reiterate, if your battery isn't deep cycle, it isn't meant to be cycled at all, but to be kept full at all times. Any amount of use is going to drastically reduce the service life. I wouldn't use a standard battery at all unless we're talking 15 minutes of use between being fully recharged again.

The 80 watt panel should be fine in the cigarette plug since those are usually 10 amp fused (120 watt). Many (most) of those plugs are disconnected when the ignition is switched off, so you would get no charging when the car is off.

I'd be nervous to let the solar panel charge the battery unattended because 80 watts is way above a trickle charge, and could cause the electrolyte to vaporize. You'd want some sort of charge controller if it's to be used when not running.

Won't matter if it's plugged in when you start.

That wouldn't be an accurate way to measure, and you'd need to have measured the capacity of your battery to begin with (not just rely on the rating of a new battery).

I used cheapo inline meters like these to measure loads. You could also use a DC clamp meter, which I also own.

thanks again for that reply. Makes sence to me what your coment was. Im now in the market for a deepcycle battery. Origionally i did have a DC battery hooked up to the 80 wt aray but it is now out of service.
About the aray: It does have a charge controller and long ago i found a blurb that showed how to move a fuse and make the cig plug hot all the time. The vehicle im taling about is a ram cargo van converted to a camper that i have lived in for months at a time.
History on the van: although it was a van it was set up to HM with k&n air, delete muffler, 50 psi tires and a set up to heat the inlet air hence the scangage to moniter water temp. Although not really factored i did have vortex generators on the rear "hoping" to reduce the vaccum. I did have some runs with an mpg in the low 30`s which i thought was good. The one thing i didnt do to improve mpg was run non eth. I did on the honda crz that is shown on my profile pic.
The mpg status on the van is short as while living in it i would hardly ever travel over 150 miles per day and then park at a walmart to which the next morning would be met with an idle while i made coffee via a 2000 wt inverter. 150 miles is pretty short test track for performance.
Once, although not counted i got mid 40`s mpg but was out west heading east with a really really high tailwind +30 mph.
Now back to my delima (sorry for the side notes)
Yes a deepcycle is on the list along with one of those meters but exactly where do i hook it up. Ive looked briefly at the vids on amazon and i dont think i can hook it in series with the starting batt. and my starting batt will be moved to behind the seat where the 80 watt aray is hardwired in.
So now when i got that done ill have deep cycle for starting and a standard battery hooked up via cig plug to the "grid" charged by the array..... Is this viable or do i need to make a larger AWG between batts.
Hope this wasnt too much .......? is it ranting or raving,..... porgie

If you pump power backwards through your array it becomes a very inefficient infrared heater (which is how people melt the snow off their panels) which may or may not be significant to your panels. shouldn't matter forward the array just adds wattage to the system. Cigarette lighters may or may not be switched, mine are live always, but confirm the fuse size. Mine use 20 amp each.
Expect the system battery to add power to the starter battery so at least 8 gauge. I suggest fused and independent of the vehicle system.

How much fuel do you think you'll be saving? I calculated accessory load in the ranger to be <10hp for battery, coolant and hvac so maybe a quart of fuel an hour. If youre in the 50mpg class yeah it's significant, not so much down at 30mpg.

I had mentioned the setup on the array earlier and was just gonna disconnect it via a cigg plug for starting. Im retired and probably drive once every 2 wks and its usually 20 miles round trip.
I could find the answer online but since im here, your almost here ill ask you.
I was gonna connect the array to the main batt... o a new deep cycle is on the way from wallmart as i type. I have some left over #10 wire from running current to the barn. what the consensus on running 2 #10 wires to conncet the array to the main batt. now that i think about it i could take one wire and connect to each terminal and that would id have three wires although it may be risky that one is unshielded or covered. But again, back to usage im probably not gonna drive over 200 miles THIS YEAR.
again, thanks for the input it is very welcome.... porgie

Piotrsko i had one more comment. the array goes thru a charge controller and i thought there was somekind diode that prevents reverse current? OPINION: yes or no....
The vehicle will probably always be driven in daylite and sunlite as well. At one time i had even removed the passenger wiper blade and arm for drag. On the honda that i got 60mpg i had removed the pass wiper, rear wiper + had wheel spats. even debadged it (dont know if it helped) The 60 mpg probably came to be over 5 or 6 cold starts too.
So now that im talkin about the honda crz heres a good fact" i bought the car in 2016 for $22k.. had 29000 miles on it... sold it to Carvana, i guess, 5 weeks ago for $20700. I hated to sell it but it was too good to be true...porgie

Doubling is twice as good and half as dangerous However, to increase wire gauge size you need 4.

Realize I am spitballing based on I really don't know how much actual you'll see but I dislike dash fires intensely. I observed Some young lady plug a lipo boost starter pack into her cigarette lighter with some awful tiny chinese wiring then lived to drive off when it started.

how long?
 

I lost an alternator 1,500-miles from home. It was a weekend. I might have waited days for a part, at $100/day for a motel room.
A casino courtesy bus took me to the local Wal Mart. I bought a battery charger and a spare battery. Charged the original battery overnight.
Left for home in the morning, driving constant loss only during daylight, until the ignition failed at around 500-miles. Swapped batteries and continued on until dusk, then grabbed another motel room. Rinse and repeat.
Made the trip home with no alternator.
So, for me and the T-100, it was about 500-miles on a battery.

It's not really the miles that drain the battery, but just the ignition being on. In other words, you tend to get a certain number of hours on a battery charge, and you could spend those hours idling in traffic, or screaming down the freeway.

Dad lost an alternator in CA (I-5 south) in the van and we coasted into a rest stop. Someone was willing to put jumper cables on long enough to get enough of a charge that we made it to a parts store where my dad replaced the alternator.

This is why you want a diesel with a hand-crank starter. Maybe a mainspring with a winding crank.

It's why I bring an electric unicycle with 25 mile range with me on trips, and a few basic tools... and a 12v battery jump pack.

If I lost my alternator, I'd hook up the boost pack and continue on.

I'm sure multiple smaller 12's would last longer, 5 or 6 7.5 sla's?. A new alternator would be easier especially at night

Heres what ive done, please tell me what you think. the extra battery is behind the driver seat. i grounded it via the seat frame and run a 4 conductor #12 wire to the main battery in the engine compt. I did find an old switch from one of those power pacts that i can shut off the second battery at iny time, i hve and will not use the cig plug for charging but the circuit that i have used for years, the only difference is now the array is charging two batteries instead of one, thx for your time, porgie

Sounds good to me. I'd just shut off the second battery during starting as 4 x 12gauge wires may be good enough for everything except starting currents.

Also, just in case you didn't know this, although you probably do, use the same amount of wires to the ground. (I knew a guy that would run thin wires to ground and negative and fat wires to possitive thinking that power only ran through the possitive wires.)

There's a fuse somewhere in there too, right?
https://i5.walmartimages.com/asr/ea6...17e359a6c.jpeg

Thanks for all the input and the system is up and working, the one mod i do want to add is fuse the second battery, ive found a 50 amp fuse that looks like it was one of those teenager high performance stereo speaker system. The fuse holder is approx 4 mm dia wire so that should be 7 awg ( right?)
So now im wanting to hook this up to my bat to bat + link that is 4x #12 wire. Is that fuse too large for the 4x12 wire and if not it should be as close to the main battery ??? right.
Thanks again for all the hints, helps, comments, and stories....porgie

I guess the old time diesels were once you got them runnin you were fine. My newer diesel tractor does operate that way you need power to hold open a fuel shutoff valve thats by the fuel control that is" how do you say" spring operated closed electric current to open.
Ive had to replace the ingition sw once because it was sending the wrong signal.
WRONG SIGNALS: Now there a subject or a forum of its own !!!!!!!

12gauge wire is used in applications from 15 to 20 amps (max, depending on things like wire insulation temps). So times 4 would get you 60 to 80 amps. So 50amp fuse sounds like a very good choice to me.
That was my old 1984 VW Golf diesel. It had a solenoid that held open the shutoff valve. That was the only electrical thing needed to keep the engine running.