[JayDubya]

My experience with today's batteries is that they seem to be designed to 'self-regulate' when charging. If the charging voltage is between 13.5 & 14 volts (like in your car), they only draw somewhere around 20 amps charging current, even when severely depleted. The only way I can get them to accept more current is to crank up the boost (15 volts or more) on my big charger. Has anyone else noticed this phenomenon?
This leads me to think that you could parallel two or three batteries with no problems on a stock charging system, as long as you aren't having to run several things at once while driving (or you can hold off pumping the bass for enough time to charge'em back up).

 

[Astroclyde]

Kirchoff's rules to the rescue!

 

[KHPower]

We must also remember that no matter how many batteries we run a amp lets say one that draws 500 amps of current , will not get that. I just replaced thje stock alternator which only puts out 105 amps going 60 down the high way with a Ohio generator which puts out over 250 amps at idle and upwards of over 500 going 60 mph.

 

[DaveAstro]

interesting reading, this is something I have wanted do in my van for ages. use the existing alternator to run the van, and the secondary to run my stereo and other added lights, etc.
your setup is reverse of mine, where your AC was and the new alternator went, is where mine already is in the 90, my AC us in the driver's side where your stock alternator is. I wonder if swapping the AC for an alternator would be as straight forward as it was for you.
it's nice having two vans now, I'm not as afraid to get into something like this that might take my van off the road for a day or two.

 

[JaxSPL]

Hey Austin, how is the weld on the adapter holding up after, what, 2/3 years? This is my main concern. When I had my second alternator installed the bracket broke. The belt pulled the alternator into the thermostat, which broke. I had to get a lot of work done. I didn't have an adapter made like yours though, which may have been my problem.
I know it's been a while, but, do you have the measurements of the bracket you made? That would probably help out people a lot that are wanting to do this.

There is another place, for some people, to add another alternator. My van has the bracket for the smog control thing but it's empty. With some modification an alternator can be installed there. So for those that don't want to lose the AC, try looking in that area.

I also found another place to get alternators, tejcurrent.com. Right now he looks like he's building for newer vehicles, but I've contacted him about older ones also.

 

[cookiemonster59]

I've already listed my 'credentials' in a previous post on pwr. window problems, but I'd like to chime in my 2 cents here. Here's my opinion on the subject of two alternators/batteries:

1. Correct me if I'm wrong, but I was always taught that a GENERATOR creates DC voltage, period !!. An ALTERNATOR creates AC voltage, which it then converts to DC via Silicone Rectifier Diodes (SCR's). Also, both generators & alternators only produce voltage/current when the motor is running!!

2. A battery is primarily designed to supply voltage to the starter & ignition system when the vehicle is being started, or to the accessories in the 'Aux' position. The only time the battery feeds into the ignition system is when your alternator output drops below the Total Electrical Demand (TED). This is why your vehicle will run for a time after the alternator ceases to produce sufficient voltage/current to keep your ignition system & accessories running, but eventually your vehicle will quit running when the battery voltage drops below a certain level (usually 10.5 volts!!).

3. After the vehicle starts, the alternator is supposed to provide all the electrical power for the ignition system, AC, lights, and accessories, in addition, it only recharges the battery AS NEEDED.

4. While a second alternator should recharge the battery/batteries faster, this isn't always a 'good' thing!! (Ask any mechanic/electrical systems tech about the difference between 'Fast' & 'Slow' charging of batteries!!)

5. If it were me, I'd go with adding a second battery first, esp. if running power amps, AC/DC converters, a winch etc., but be sure to check your alternator's amperage output vs your 'TED', or you will be 'burning up' the Silicone Rectifers (SCR's) in it!!)

 

[JayDubya]

Amen, cookiemonster! The stock alternator is pretty stout. If someone has installed 'heavy draw' equipment like a winch or high-power amp, etc., the first things they should do is upgrade the wiring, then shoe-horn the biggest RV/marine battery that will fit in their vehicle (if needed). Without good, solid wire upgrades AND proper wire installation for their added toys, they will have issues. The bonus here is that proper wiring upgrades don't have to cost a lot of scratch.

 

[JaxSPL]

For those that are thinking about adding a second alternator, and not worried about having the AC compressor. I have found a, somewhat expensive (for what it is) adapter for you. Actually Rusty from DC Audio turned me on to this company and the adapter.
Look in the store link, under alternator brackets. I am not sure if these will work on newer Astro/Safaris, but they will for sure work on a 1988 (Rusry's van) and a 1989 (My van).
http://www.teamprojectdb.com/

 

[JaxSPL]

Somebody needs to redo this topic so the pics can load again.

 

[ibanender]

Somebody needs to redo this topic so the pics can load again.

I have dual alternators and working A/C, but I have no desire to recreate it on another van. DC Power was going to start making the bracket I made, then the person I was working with left.

 

[Nomad]

what I dont understand is that they are attachments why did they go bye bye? or did the server/forum have a hiccup since then?