Alternator Output

[Chris]

I've had a few battery issues lately, one with my wiring of the solenoid on my dual batteries which I thought I fixed only to find I turned one setting into a kill switch. :confused:

Apparently I crossed some circuits adding a new CB and though I thought it was fixed I just changed the problem. Got into again today and due to my love of electrical stuff ended up removing the switch and solenoid and just wired them together. Note to Pete: Yeah, the Painless setup wasn't painless.

Once everything was put back together, the CB re-installed and wired I was pleased that it was nice & clean and rid of the dual setup wiring problem only to find my batteries dead. (Yeah, both which makes me rethink getting rid of the isolator.) :p

Since I got distracted and did some other stuff like fixing my wayward headlight which was damaged by some cowboy in an ATV slamming into me last Winter. (BTW Pathrat, thanks for mentioning the dim headlight a while back.) I'm no longer that jerk with a headlight shining into rear view mirrors, second floor windows, etc. :lol:

Too much background? Okay so I had my iPod playing through the radio during this work but was surprised the batteries were dead. I've always heard that an alternator should be putting out between 13.8 to 14.2 volts and mine's at 13.7. Is it an issue? Maybe I just need to quit taking so long to get something done or put a radio in the garage? :o

[Brody]

Well, you essentially ended up doing what I did with my batteries-wiring them together and calling it good. Guess that's why you ended up with my 'not so painless' wiring setup. Which, incidentally, should be 'painless' as it is only a fancy Ford type solenoid and a switch..

13.7 isn't bad on the alternator and anything above that is good. The quick and dirty way to check your alternator is to start your rig and then pull the positive cable from the battery. If it keeps running, you have a good alternator. If it stops, it is bad...

Some of those headlight rewiring kits plumb a line off the alternator, and the additional voltage is one of the reasons the light output increases so much.

I have a small short in my rig that causes it to run down the batteries if it hasn't been started in 3-4 days. It has driven me and everyone at ORS batty....and I am only adequate, but they are good...

[Chris]

Thanks Pete, appreciate the confirmation. I still would like to isolate a battery, kind of frustrating to have dual batteries both die.

[Jimmy]

Hmmm... might have to buy a nice, fancy (high-dollar) isolator to handle all that automatically if you want a maintenance-free setup that keeps both batteries charged and such. But, man are those things pricey!

Anyways, to the dead batteries. Any chance you left the headlights on after adjusting and testing them? It takes a pretty big source to drain a battery quickly. I would think the radio would have to play for days before running them down to nothing.

To find a circuit that is causing a drain, here's a shade-tree method. Take a good brakelight bulb, solder on two lengths of wire (I'd recommend making them long enough to get from your battery to any/all fuse boxes on your vehicle), add on alligator clips, and clip it to your battery. Run the bulb to a place where you can easily see it when you're located at your fuse panel. Methodically begin removing and reinstalling one fuse at a time. If the strength of the light emitted doesn't change when a fuse is removed and reinstalled, then that is NOT the circuit causing the drain. Keep going until you see the light emitted from the bulb get brighter when a fuse is removed from a circuit. The light should drop back down when the fuse is reinstalled. That's the circuit creating the drain - you are effectively stopping the drain when you remove the fuse, thus sending the previously-drained energy over to the bulb increasing its brightness. Do this on all fuses you have (whether they're in a block or in-line) until you find it. If you don't find it, consider anything that is wired directly to the battery or a hot post/pole that was added to the vehicle. Then, start disconnecting one wire at a time on those hard-wired accessories until you find it.

It takes some time to track it down this way, but it can be done by anyone.

[Chris]

Hmmm... might have to buy a nice, fancy (high-dollar) isolator to handle all that automatically if you want a maintenance-free setup that keeps both batteries charged and such. But, man are those things pricey!

Anyways, to the dead batteries. Any chance you left the headlights on after adjusting and testing them? It takes a pretty big source to drain a battery quickly. I would think the radio would have to play for days before running them down to nothing.

To find a circuit that is causing a drain, here's a shade-tree method. Take a good brakelight bulb, solder on two lengths of wire (I'd recommend making them long enough to get from your battery to any/all fuse boxes on your vehicle), add on alligator clips, and clip it to your battery. Run the bulb to a place where you can easily see it when you're located at your fuse panel. Methodically begin removing and reinstalling one fuse at a time. If the strength of the light emitted doesn't change when a fuse is removed and reinstalled, then that is NOT the circuit causing the drain. Keep going until you see the light emitted from the bulb get brighter when a fuse is removed from a circuit. The light should drop back down when the fuse is reinstalled. That's the circuit creating the drain - you are effectively stopping the drain when you remove the fuse, thus sending the previously-drained energy over to the bulb increasing its brightness. Do this on all fuses you have (whether they're in a block or in-line) until you find it. If you don't find it, consider anything that is wired directly to the battery or a hot post/pole that was added to the vehicle. Then, start disconnecting one wire at a time on those hard-wired accessories until you find it.

It takes some time to track it down this way, but it can be done by anyone.

Good advice al always Jimmy. What would be a less expensive, manual way of isolating one battery? Is that practical?

As far as the battery drain I didn't leave the headlights on because they were on the bench. I'm suspecting my weird wiring was the problem and they were low when I started the work. I'll see within the next week or so I'm sure.

Thanks for the shade-tree method, really hoping I don't have to use it.

[Jimmy]

What would be a less expensive, manual way of isolating one battery? Is that practical?

The cheapest way would be with a simple battery switch. This link has several examples of battery isolators (diode, switch, solenoid): http://www.custombatterycables.com/battery_isolators.htm You manually select which battery to use, or you can use both. I've seen these on boats, but they work the same on a vehicle.

It's practical so long as you occasionally switch to the other battery from time-to-time. If you've gone a long time between switching, then I'd recommend you put a trickle charger battery charger on that isolated/hasn't been used for awhile battery to do the charging vice making your alternator do the work.

Some folks don't realize how much strain it places on an alternator to perform the charging of a dead battery. You only want to put your alternator through that when it's your only option.

Now, an isolated battery shouldn't lose too much of a charge, say, over a month or so. If you can remember to flip that switch once a month and drive on the opposite battery for a bit, then you'd be set.

Some folks don't have it in them to remember to do that - some people don't tick that way. So, using a manual switch wouldn't be the best way to go. So long as you're honest with yourself about your ways, then you can figure out what method will work the best for you. If you'll remember it, awesome. If not, another method would be a better option.

[Chris]

Do you know of any manual switch? I did a search and couldn't find enough information regarding connections especially since I used 0 gauge wire for the second battery. In my search I did find this which reminded me that I have it in my garage. It came with a great eBay buy I made quite a while ago. I'll dig it out and look at it and see if it looks like it would work.

[Brody]

Well, I am one of those people who would never ever remember to switch the batteries back and forth which is one of the reasons why I said screw it and wired them together. I can't even remember to put my glasses and keys in the same spot when I come home...frustrates LaDawn to no end as she is so organized...

[Jimmy]

Do you know of any manual switch?
Like I mentioned, I'm familiar with them from the marine world. So I checked out the "battery switches and cable" section at West Marine where they had several offering from under $35 heading up to $150: http://www.westmarine.com/webapp/wcs/stores/servlet/SiteSearchView?jspStoreDir=wm51&catalogId=10001&view100page=100&in_dim_search=1&Ntt=Battery+Switches+%26+Cable&N=377+710+1642&page=CategoryDisplayLevel1&y=0&omniTag=Category%3aBattery+Switches+%26+Cable&x=0&PopularCat=No&storeId=10001 Make sure you pick one that works on two batteries and covers your amperage needs.

I did a search and couldn't find enough information regarding connections especially since I used 0 gauge wire for the second battery. In my search I did find this which reminded me that I have it in my garage. It came with a great eBay buy I made quite a while ago. I'll dig it out and look at it and see if it looks like it would work.

I would guess it would work. That's the diode-style from the link I posted above. You use one battery for starting the vehicle and one battery for powering accessories. The diode keeps the batteries from feeding on each other - a weak battery will suck energy off of a strong battery, which is a quick way to kill the batteries (i.e. it shortens their lifespan). With this system, my limited understanding is that one battery is always the starting battery while the other is the accessory battery. The only way to use the accessory battery to start the vehicle would be to manually disconnect the batteries and swap them.