Could A Stock Alt Handle More Than 1 Battery?

[DUBIE]

Well first off what type vehicle?

Second it should be able to keep up to 3 batts up if you bench charge them first.

Added voltage to 15v will keep them up with a stock alt.

Simple easy fix mane!!! What type of car is needed for better answers for your topic. Thanks,

MLA

its a 96 dodge intrepid...

[audiofanaticz]

its a 96 dodge intrepid...

It looks like no matter which motor is in your car (either the 3.3L or the 3.5L) they both have a same 90 amp alternator.

Id say your safe to add 2 bigger batteries for sure, and your alternator should not have a strain trying to keep them charged.

But Im not the expert like mla

[DUBIE]

It looks like no matter which motor is in your car (either the 3.3L or the 3.5L) they both have a same 90 amp alternator.

Id say your safe to add 2 bigger batteries for sure, and your alternator should not have a strain trying to keep them charged.

But Im not the expert like mla

o aight..tanx 4 da advice bro...preciated...

[Eskii]

how can you find out how many amps your alt pushes or has.?

Most Auto elects have current meters. Look like a clamp that goes over the top of wire, counts the electrons apparently

[Charger]

I have four 150amp hour batteries plus a 90amp hour battery on my stock 50A alt. It 'handles' the batteries and keeps them charged at 14.4v. However it can't charge them once they are drained down quite a bit. If

[Charger]

I have four 150amp hour batteries plus a 90amp hour battery on my stock 50A alt. It 'handles' the batteries and keeps them charged at 14.4v. However it can't charge them once they are drained down quite a bit. If you have a large bank of batteries I would definitey recommend an alternator upgrade, I will be doing mine shortly.

[Eskii]

I had two 90Ah's in my Patrol with a 50 Amp Alternator!!!!

Oh yeh, sniff sniff... wat's burning.... lol

All depends on battery size and Alt output.

[All Night Long]

I killed a stock 120 amp alt with 2 3800 amp 8d's, but that's a total of 7600 amps that were in the rear of the car plus the stock battery which was around 800. So, 8400 amps of battery on a 120 amp alt with 1 run of 0 guage will definately kill your stock alt. But hey I was 17 and didn't know any better. Just gave me an opportunity to use my lifetime waranty on the thing Right now I charge my stock batt which is 750amps and also a Powermaster D3100 which is listed around 2500 amps and I have a stock 110 amp alt. The alt charges the batts fine and I still put it on the charger every week for a night or two. There's nothing better than seeing your battery voltage at 14.8 volts when you start the car in the morning. Oh yeah, I haven't even done all of the big three yet in my new car either. The alt is a pain in the ass to get to so I haven't even got to run 0 guage to it yet, but stock ground is upgraded and also grounded to the engine block. What are you trying to run off of a stock alt? Because I can say that you might kill it with a huge battery in the trunk with 4 guage runnning to it.

[audiofanaticz]

It really dont matter how big the batteries are, they will charge just the same as a small battery (it just may take longer). The way most screw up their alternators is by running their batteries dead and then use the alternator to charge them. The alternator is not a battery charger, it is just to keep the batteries charge maintained.

[missinglink]

Let me expand a bit on what you can (and can't!) do with an alternator, and where some of the stories come from.

Older alternators with a regulator mounted on the firewall (OEM) were simple systems. If you open one of those old cans, you will find a coil, a pair of contacts, and a couple of resistors. They have only 2 or 3 steps, depending on the make & year of the vehicle - old Chrysler products had only 50% & 100% output. There was no temperature sensing of any kind.

Now, if you hooked that system up to a couple of 8D batteries that were almost dead - you will kill the alternator every time. The voltage regulator will keep the field running 100%, without regard for the alternator temperature. Someplace past 250 degrees either the diodes fail, or the insulation does. Dead alternator.

One of the many reasons OEM's went to internal regulators was the placment of a temperature sensor inside the actual alternator. If you push a stock IR alternator too hard, it simply reduces field current. Alternators keep getting better. Gently pry the cover off of a 3G ford regulator sometime. You will find a small computer, with dozens of surface mount components. Temperature sensing. Field decay time measurement. Load anticipation. You can put a dozen 8D batteries on that alternator, and charge them all.

Older alternators were also rated with a system that assumed they would only need maximum output 10% of the time. A 60 amp ford 1G was only good for 60 amps for a few minutes - not hours and hours. Cars had 30 amp generators a few years before, and the total system load before A/C was common was about 25 amps.

Now some cars pull 42 amps at the radiator fan. New alternators have dual fans, high temp components etc. They are designed to make rated load for longer periods of time. A caddy with dual electric fans, A/C, electric windshied defrost, power everything... came with a 140 amp alternator. At idle the system load can be 100 amps at times. The battery has to provide some of that power at idle, but once you accelerate the alternator is replacing that power - recharging the battery - and running the system.

The short answer to the original question is yes, your 90 amp alternator can take care of two batteries. The bigger picture is how much load are you putting on the batteries? If you run a 5kw load all the time, the load eventually wins. Your battery voltage will gradually drop if you are taking more out than you put in - just like your bank balance. Running lots of batteries, and charging overnight is one way around adding charging capacity. Charging at a slightly higher voltage also helpd cover the gap in load vs charging capacity. By moving the charging curve up a bit, you cause the alternator to put out full power before the voltage in the batteries drops by 15% - basically extending your storage capacity by 15%.

'Link