Powerhouse Posted January 4, 2009 Report Posted January 4, 2009 well...my battery took a dive yesterday...i hadn't started the car in only about a week...and it cranked twice and then faded away. Kinda odd...I live in San Diego now...not ever colder than 40 yet in the garage...and that's probably the coldest it gets in there. The battery is only about a year old. I'm thinking of getting an Optima 6 volt instead...there lighter too so i'm sure to pick up some speed..hahaha... The old battery is charging now on the 6volt 6 amp charger...the needle was at 4 and has dropped to below center...did that mean the battery drained from charging? I don't understand that thing... I then tested the cells with that hydrometer (or whatever it's called) and it said it was fair in all the cells. So I tried to start the car....STARTED RIGHT UP! Weird, and now the amp meter seems to not be charging like it used to. It would go all the way to the right when I was at about 2K rpm...now it only moves half way there. ANY IDEAS? I tried repolarizing the generator by touching the B to the A on the voltage regulator...didn't spark or anything. Any way to tell when the B terminal is supposed to be open or closed? Why does it close or open anyway? Quote
Powerhouse Posted January 4, 2009 Author Report Posted January 4, 2009 regulator in my car is VRP-4101-A and also says max amps 22. meter shows 6 volts solid when circuit breaker is closed...I manually closed the point to test this. ran for 10 minutes...didn't close yet... Quote
Norm's Coupe Posted January 4, 2009 Report Posted January 4, 2009 How often do you start or run your car? If not much, that could be why the battery only lasted a year or so. When a lead acid battery isn't used on a regular basis the plates get a scale on them from the battery acid. Once that happens, the battery is toast. However, most of the time you can still charge the battery up and start the car a few times. Then the battery will go down again shortly. While this is all happening the battery may test like a new one, but it still won't hold a good charge due to the scale on the plates, so it's then time to replace it. I know, I've had to replace several batteries over the years for this reason. Finally bought a Battery Tender about a week ago and put it on my new battery. This keeps the battery active and charged up even though you don't start the car. If the battery goes down just a little, it will start charging. When the battery is completely charged up the charger goes into a float mode and keeps it at it's peak level of charge all the time. This way the battery is always ready to go, and you don't have to worry about building up the scale on the plates from non use. If you don't use an Optima for long periods it will go down from non use too. My son also keeps a battery tender on his Optima in his 80 Firebird during the winter. By the way. Extreme high summer temperatures will have the same or worse affect on a battery, according to the battery people. So........it doesn't have to be cold outside to ruin a good battery. When the battery plates on scaled, it will also make your AMP meter jump around and act weird. That's because it's not charging correctly. Quote
Plymouthy Adams Posted January 4, 2009 Report Posted January 4, 2009 when you cranked your car on a weak battery the amp guage will go total right at the beginning and taper off as the battery nears charge..as you have just put this battery on the charger for a spell and thus cranked a recently started vehicle, fewer amps were removed from the battery so the necessity to replace is less therefore the lower reading on the amp meter. The thing to do a this time is to remove a battery cable and place your test light inline..if it is lit with all doors closed and accessories off..then you have a short draining the battery...if you have a clock..please unplug this..odds are the contacts are not sticking but then they could...be sure the cigar lighter is also not pushed in.. 6 volt batteries are not made like they once were..they are cheap and if you get two years on a randomly used car..you more than likely have done well...checking the specific gravity with the hydrometer is good..they should be level across the three cell...if one is lower than the other...look for a cell going dead..this will limit the batteries ability to maintain charge.. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 By the way the car is a 39 ply roadking.. Norm's Coupe - THANKS for the very informative help as usual. I drive my car at least 5 days a week. To work and back and sometimes on weekends. I have a battery tender on it now...I had the thing in my car but never plugged it in...duh! I forgot I had it... Tim Adams - THANKS as well! Now i understand the amp gauge better....I thought it would just get a higher reading because the generator was going faster...I'll check for a leak somewhere. I have no door controlled lights, cigar lighter...clock...or anything like that...just a heater, fog lights, cooler fan, and a steering column fan. When I turn any one of them on...the amp gauge shows a below middle reading. With all my lights on, heater, etc..it's away to the left. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 NEW QUESTION ABOUT Generator regulators or Voltage regulators... I have a vrp-4101-A in my 39 car. I have a 57 ply dizzy and a 53 Dodge truck engine. What VR should I have or is there a better one I should have to help the genrator work best???? Anyone have a VR part number list? Quote
greg g Posted January 5, 2009 Report Posted January 5, 2009 voltage regulator should be fine. The dist and the engine don't matter to the charging system. The reason the needle on the battery charger drops from 6 amps to 4 amps and then lower as the battery accepts the charge. It is a good sign and indicates the battery and charger are doing their thing properly. As was stated, a fully charged battery won't need a charge after starting a car that starts quickly. The voltage regulators job is to allow the genny to put back in what the starter took out, then maintain the battery at its prper level, as overcharging boils out the electrolite. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 ah...even more enlightening wisdom on the charging system...THANKS! So, i just looked up the generator number in my 1949 motors manual...it's a GCJ-4802A-0 which makes it a 1937 Plymouth generator...which has a max output of 26 Amps. My VR says it has a max amps of 22 amps. Is that bad or good or does it not matter at all? Should I get a newer generator and VR that match with a higher amp ouput like 35 amps in a p-15 generator? Would that help with power at all...like brighter bulbs and things? I have new correct heavy gauge battery cables and a wire harness installed...good grounds too...pretty clean all around... Quote
wldavis3 Posted January 5, 2009 Report Posted January 5, 2009 Powerhouse, On my car, the way to test the charging system is to attach a voltage meter to the battery (+ to +, and - to -), start the engine and while holding the accelerator linkage (in the engine bay) at a high idle, the reading on the meter should read at least 7.2 volts, but probably not higher than 7.5 volts. Backing up one step, the battery should read at least 6 volts with the engine off. I had a problem with my voltage regulator, as it was not putting out 7.2 volts at high idle and it was draining my battery (engine would not start). On P-15's and later 6 volt systems, to check whether the fault lies with the generator or voltage regulator, you momentarily ground the field post of the generator. When you do that, the ammeter in the vehicle should "peg" the needle all the way to the positive side. This indicates that the generator is working O.K. I took my battery back to the place I bought it (a "mom & pop" auto parts and tractor supply store) and told them it would not start my car eventhough it was only about two years old. They put a tester on it and said it was "good" -- still showed a 6 volt reading but was discharged. The owner there told me to put a baby aspirin in each cell and charge the battery up and it would be O.K. I did that, and so far, it is doing O.K. since I changed out the faulty voltage regulator. Hope some of this helps. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 ...a baby aspirin... Neat...i'll try that. The battery did register 6 volts with engine not running. If the circuit breaker is open on the VR, does that mean the battery is not getting charged? I'm guessing it closes when the drain is starting on the battery.... Quote
Young Ed Posted January 5, 2009 Report Posted January 5, 2009 By the way. Extreme high summer temperatures will have the same or worse affect on a battery' date=' according to the battery people. So........it doesn't have to be cold outside to ruin a good battery.[/quote'] Norm you are very right. My 94 Dakota has had 3 battery replacements in its years. The 2 I did were in July/August and pretty sure the first one Dad did before I got it was in the summer too. Quote
greg g Posted January 5, 2009 Report Posted January 5, 2009 The vr works by opening and closing the cut out circuit. This circuit energizes the field windings. The generator is just a spining armeture till the field is engergized. The magnetic field is creaed when the circuit is on, and gone when it is off. (That is why grounding the field wire tests the genny, it bypasses the VR control and allows the field to be energized) The length of time the field is engaged controls the genny's out put. That is why you can see the needle moving in sharp actions instead of sweeping whenit is charging. So when you are going dow the road with a fully charged battery, the gauge shows a neutral position niether charging nor discharging. When you step on the brake it probably goes to discharge for an instant, then the VR senses the load, closes the points makes the field and puts bake what jusice the brakes light took out, then they open again when the bat is back t normal charge. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 OK...so the needle shouldn't always be going to the right when rpms are advancing. The points on the circuit breaker close when the battery needs a charge. OK...i think I got it. I will take the cover of the VR and see what happens when I turn on the lights, i'm guessing it should close the Circuit...correct. ANyone know if the vr needs to match the genny? Or if a better max amp output is better? Quote
greg g Posted January 5, 2009 Report Posted January 5, 2009 the vr should not allow more amps than the genny is rated for, as doing so will over heat it. Liquid solder spinning off the rotating armeture is not a good thing. and yes you should see the poits close when a load is placed onthe system. although they will likely cycle if the battery is in good shape and up to fully charged. Quote
Powerhouse Posted January 5, 2009 Author Report Posted January 5, 2009 OK... so a genny pumping out 26 amps is ok with a VR rated for 22amps. If I were to get a 35 or 40 amp genny and pair it up with a 35 amp VR that would allow for a quicker recharge of the battery.... So I can use more accesories at once? Quote
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