Can the alternator charge two batteries?

[CB7Nub]

I'm not sure on this one, I was wondering if the stock alternator can charge two batteries? (one for main and other for alarm) My alternator has been rebuilt a couple years ago.

[Cautrell05]

They do it on diesel trucks all the time. Only catch is that both batterys should be same brand, size and age. I have seen guys get by with mismatched batteries but have also seen alot that will draw each other down if they are not matched.

Nick

[kouzie]

you can also upgrade your alternator.

[CB7Nub]

Yeah I was thinking of upgrading, but I have no idea what to look for. What kind of alternators are there? Are there aftermarket alternators or just swap with a different model?

Dang oh well if I can't mix battery types forgot about it, thanks for the info.

[doojo0014]

u can get the 9? preluede i forgot the year but it is cheaper than the OEM but gives out 95amps V OEM 80amps i think its a 94-97 but its matches up the same as OEM


someone help me out

[**CB7**]

*UPGRADE* the alternator to a high output one. I would get one in the range of 130amps-170amps.

[ChIoVnIdCa]

other for alarm)

If you are worried about if the factory alt can run two batteries then I assume you are talking a second full or at least another car battery...


Just buy what is made for it... It will isolate the alarm from the vehicle when the battery is disconnected so if a thief happens to hit the lights on or anything it would not drain the back up.........


http://cgi.ebay.com/ebaymotors/ws/eB...d=200375772093


The battery that the dei piece comes with is hit and miss .. I would be this battery along with it and upgrade it before the install

[CB7Nub]

How can I hook that DEI kit up to the alternator? Looks like a great thing, small and cheap!

[TheFirstNutZo]

I'm not sure on this one, I was wondering if the stock alternator can charge two batteries? (one for main and other for alarm) My alternator has been rebuilt a couple years ago.

Car battery chargers generally charge at 2amps or 10 amps. Certainly your alternator has at least an extra 2 amps available?

The bigger question would be why? There is a lot of complication that comes from multiple batteries with the isolators and whatnot (see here: http://www.bcae1.com/battiso.htm). If you are worried about a thief breaking into your hood and disconnecting the battery, relocate your battery to the trunk. Put sensors under the hood so that the alarm goes off if the hood gets lifted or the trunk gets opened.

Don't forget that it is a VERY insecure car and a determined thief is always going to find a way -- don't put very expensive things in the car if you can't afford to have them stolen.

[TheFirstNutZo]

If you are worried about if the factory alt can run two batteries then I assume you are talking a second full or at least another car battery...


Just buy what is made for it... It will isolate the alarm from the vehicle when the battery is disconnected so if a thief happens to hit the lights on or anything it would not drain the back up.........


http://cgi.ebay.com/ebaymotors/ws/eB...d=200375772093


The battery that the dei piece comes with is hit and miss .. I would be this battery along with it and upgrade it before the install
http://www.zbattery.com/Universal-12...category=62965

Great idea, and much simpler than a multi-car battery setup (well, not so much simpler, as all self contained and already figured out).

[CB7Nub]

Yeah I'm not putting really expensive stuff in my car, I know even with all the best alarms and all of that the best thief can get anything. But there isn't that many around, well where I live, just a bunch of high schoolers.

What I'm trying to ask is there a way I can make the backup battery re-charge from the stock alternator when the engine is on? Because what if you just leave the battery hooked up all the time to the alarm, it will die overtime and you will only know when your alarm doesn't work.

[WhiteGhost]

I've ran two in every car i've every owned...The right way is to get a voltage regulator...But i also just hooked 2 up without one of those...You hook it up like you would a amp...If you put in your hatch get a box to put it in and ground it to the body an run a power wire from your first one...Some say it can put stress on your alt,But I've ran big systems this way and never had a prob.No light dim or nothing...I never had a dead battery either.....Hope this helped

[H22Artman]

a very common misconception among pretty much anyone is that alternators are meant to act as an onboard charger.
theyre only purpose is to recharge what VERY little voltage that was expended during the cranking phase. thats it.

this article explains it better than most:
http://www.ehow.com/way_5380734_long...y-charged.html

the alternator on our cars should be enough to maintain two fully charged and well maintained batteries, although one battery strictly for alarm purposes is total overkill.