Is this a symptom of a bad cell?

[TylerW]

Or possibly just sulfation?

My '73 Plymouth does not get driven that often and over the last couple months I have been experiencing some battery problems.

It usually takes 15-20 seconds of cranking to get gas back up to the carb when it's cold, and the starter will spin fast for maybe 10 seconds, then slow down, as if the battery is going dead. However, it will spin the engine in that "reduced charge" condition for quite a while. It does not just go down to nothing in one whack. After the engine starts the ammeter shows a significant charging level for a while as if the battery were deeply discharged.

Warm starts are fine since the engine needs only a few revolutions to start. Battery connected or disconnected between drives makes no difference so it isn't a drain. Alternator is charging well. Just curious what goes on with batteries when they lose their "surface charge" prematurely.

 

[67Dart273]

This is one good reason for being able to access cells and use a hydrometer. But even if you cannot, charge it up, let it set for a couple of hours or more, and have someone who knows what they are doing load test it.

 

[Abodybomber]

What kind of battery? And have you considered an .0.5 - 1.0 amp trickle charger? My ancient Wally World group 27 is 6+ years old. Maintenece,(and caring) is the key for me.

 

[nm9stheham]

If it is cranking that long even at reduced speed, it does not have a 'bad cell' per se. With a bad cell, it would not hold a charge for long at all. More likely something like sulfation (just getting old and worn). The charging rate is not lying to you.

If it has removeable caps, do the following after it has set for a day or 2 after a good rive to get it charged, or after a good charge of any type: Remove the caps and connect a voltmeter to some bare steel nails with jumpers. Dip the pair of nails into adjacent cells and measure each cell voltage; on one of the end cells, you have to dip into one cell with one nail and contact the terminal with the other ot read the 6th cell. They should all be about the same, at around 2.1 volts. You can find any weak cells that way as well as using a hydrometer as above.

 

[pishta]

2 words..electric pump.

itll pump right through your mechanical pump.
If the battery cranks like gang busters then slows down, its on its way out. one cell is probably the fault. Fill them with distilled water and a teaspoon of epsom salt. Dont know how it works but it does.

 

[tekslk]

Throw a aspiran down each cell. Or buy a new battery.

 

[cudascott]

Keep your battery charged it will last a lot longer

 

[cuda65vpt]

After you get a new battery, disconnect it when you know you won't be starting the car for a while. I need to do that too, but I am a procrastinator and usually don't.

 

[GEO]

Charge the battery and have it load tested.

I recommend using a battery tender and have it hooked up when not driving .

I just normally buy the smaller ones made for motorcycles.

Never had a tender go bad in the last 20 years.

You can buy them right from battery tender or from a seller on ebay

 

[Rice Nuker]

Bad battery I agree. Take it in and have it load tested after a 12 + hour trickle charge or smart charge for an entire cycle. If you find a good auto place, they will charge your batt for you overnight and test it the next day. If the batt tests out fine then the starter or wiring is heating up and loosing efficiency.

I have cranked a 440 mopar with factory starter for 30 seconds straight and it has not slowed down more than 2-5% (estimated by ear).

I agree with pishta about the cranking time and lack of fuel in carb. We have a mild 440 / performer / 800 edl thunder. Usually after sitting overnight it takes 10 seconds of cranking, sitting for 2 weeks it takes nearly 1 minutes of cranking sometimes. Many speculations on the cause but overall reason it is - no fuel in bowl.

I just installed an economical airtex elec pump and I turn on the ig key, wait 10 seconds (till the carb fills with fuel), pump it once or twice (colder weather requires 3 pumps) and it immediately fires like it was fuel injected and fast idles on the choke nicely.

[ame="http://www.amazon.com/Airtex-E84070-Electric-Fuel-Pump/dp/B000DT7Y7U/ref=sr_1_5?s=automotive&ie=UTF8&qid=undefined&sr=1-5&keywords=airtex+universal+electric+fuel+pump"]Amazon.com: Airtex E84070 Electric Fuel Pump: Automotive[/ame]

.

 

[65cuda360]

With a dead cell the voltage across the battery terminals will be down by about 2 volts. Test while charged will usually be + - 12.5 volts. With a dead cell they will read + - 10.5 volts.

 

[TylerW]

This is a "maintenance-free" 60mo Carquest battery with no date notation anywhere. It's probably 4-5 years old.

I got diverted onto a brake repair project but I'll test it or have it tested.