How do you test for a dead cell ?

[tommyk90 5,000+ posts]

Best way is to put it on an agm charger and see if it takes a charge.

Actually the best way to test for a dead cell is to hook it up to a load tester.

Just because it sits at 12.x volts doesn't mean there isn't a weak cell in it somewhere.

Hank (2000lade) had to do this to all of his batteries after SBN and ended up finding 4-5 dead batteries even though they were sitting at 12.6+. Once he put a load tester on them it would drop down to 9 volts.

I actually thought about doing this with my two yellowtops just to make sure they are still in good shape.

 

[SicAudio 5,000+ posts]

12.5 to a 12.6 seems a little low are your connections all good and solid? Grounds all solid? Does it struggle more when starting?

a little battery 101 here:

all 12 volt automotive use batteries, agm or otherwise all have 6 plates that each create a 2.1 ( sometimes higher ) voltage, so multiply that by 6 plates and you have the defacto standard of 12.6 .

I would say if its at 12+ volts you cant have a bad cell, since it is mathematically impossible. now if it is a 16 volt battery the story is different.

some agm batts rest at a higher voltage but not all, that is why even Kinetic recommends that you buy multi batteries all at the same time from the same place, and make sure the manufacturing dates are within a reasonable period of each other ( 30 days or less )

 

[NoCoSPL 10+ year member]

Actually the best way to test for a dead cell is to hook it up to a load tester.Just because it sits at 12.x volts doesn't mean there isn't a weak cell in it somewhere.

Hank (2000lade) had to do this to all of his batteries after SBN and ended up finding 4-5 dead batteries even though they were sitting at 12.6+. Once he put a load tester on them it would drop down to 9 volts.

I actually thought about doing this with my two yellowtops just to make sure they are still in good shape.

This^^ Also after you put a load on it test your voltage and recharge. draining and charging your batteries forces the electrolytes out of the negative plate making for more capacity once fully charged.

 

[TnT_Sounds 10+ year member]

This^^ Also after you put a load on it test your voltage and recharge. draining and charging your batteries forces the electrolytes out of the negative plate making for more capacity once fully charged.

Electrolytes? The shit in sports drinks? I had no clue those were in batts. //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif I thought they were just full of neutral ions and electrons. I failed chemistry though //content.invisioncic.com/y282845/emoticons/frown.gif.a3531fa0534503350665a1e957861287.gif

 

[audiolife 5,000+ posts]

If you do not have a load tester seeing if the battery will take a charge and then testing it out by starting the vehicle isn't bad, especially if you start it up 3 times shut it off and come back to it 15 or 20 minutes later and do the same thing. If it gets weak or noticeably weaker after being fully charged on the charger you more than likely have a bad or sulfated battery. If it passes this test then gets weaker as the vehicle runs more than likely you have a wiring issue or a bad alt. I have 2 cheap load testers (led type) one will read that a battery is fine even though it is not even strong enough to start a car. I also have access to a dialed carbon pile load tester. To really see the condition of the battery you would actually have to cycle the battery and test its discharge and recharge capabilities. If you take the battery to autozone to be load tested you would have to make sure the guy running the load tester actually knows what he is doing as I have seen them call good batteries bad and bad batteries good (be it an agm or flooded battery) and I would venture to say the data gathered wouldn't be that specific. Also 12.6 volts on a flooded battery is only around 90% charged. Agms would read more like this:

"Voltage at DOD

Here are some typical voltages vs. depth of discharge: (figured at 80% max discharge)

1% = 12.91 Volts.

10% = 12.8

20% = 12.66

30% = 12.52

40% = 12.38

50% = 12.22

60% = 12.06

70% = 11.90

80% = 11.70

90% = 11.42

100% = 10.50."

A load test can/will tell you if the plates are damaged IF it is done right. If the battery comes off an intelligent agm charger not holding anymore than 12.6v I would come to the hypothesis say it has some plate damage. Mine as we speak is resting at 12.78v and it has not seen a charger in months. Typically the manufacturer will tell you it is ok to put the battery in if it rests at 12.5v or above but from that standpoint the alt should charge it up to the 12.7 range at least. If the battery has sulfated plates you can cycle it on a charger that has a desulfate setting like this. http://www.sonicelectronix.com/item_13271_Kinetik+KIBC12-35.html

 

[NoCoSPL 10+ year member]

^^^^ knows what's up

 

[TnT_Sounds 10+ year member]

If you do not have a load tester seeing if the battery will take a charge and then testing it out by starting the vehicle isn't bad, especially if you start it up 3 times shut it off and come back to it 15 or 20 minutes later and do the same thing. If it gets weak or noticeably weaker after being fully charged on the charger you more than likely have a bad or sulfated battery. If it passes this test then gets weaker as the vehicle runs more than likely you have a wiring issue or a bad alt. I have 2 cheap load testers (led type) one will read that a battery is fine even though it is not even strong enough to start a car. I also have access to a dialed carbon pile load tester. To really see the condition of the battery you would actually have to cycle the battery and test its discharge and recharge capabilities. If you take the battery to autozone to be load tested you would have to make sure the guy running the load tester actually knows what he is doing as I have seen them call good batteries bad and bad batteries good (be it an agm or flooded battery) and I would venture to say the data gathered wouldn't be that specific. Also 12.6 volts on a flooded battery is only around 90% charged. Agms would read more like this:"Voltage at DOD

Here are some typical voltages vs. depth of discharge: (figured at 80% max discharge)

1% = 12.91 Volts.

10% = 12.8

20% = 12.66

30% = 12.52

40% = 12.38

50% = 12.22

60% = 12.06

70% = 11.90

80% = 11.70

90% = 11.42

100% = 10.50."

A load test can/will tell you if the plates are damaged IF it is done right. If the battery comes off an intelligent agm charger not holding anymore than 12.6v I would come to the hypothesis say it has some plate damage. Mine as we speak is resting at 12.78v and it has not seen a charger in months. Typically the manufacturer will tell you it is ok to put the battery in if it rests at 12.5v or above but from that standpoint the alt should charge it up to the 12.7 range at least. If the battery has sulfated plates you can cycle it on a charger that has a desulfate setting like this. http://http://www.sonicelectronix.com/item_13271_Kinetik+KIBC12-35.html

any word how the charger works in bulks? I know Schumacher makes one somewhat similar for AGM with a desulfate setting and it claims to be ideal for charging large 12v AGM battery banks in bulk. If the Kinetik is comparable, I'd save a few hundred $$

 

[audiolife 5,000+ posts]

any word how the charger works in bulks? I know Schumacher makes one somewhat similar for AGM with a desulfate setting and it claims to be ideal for charging large 12v AGM battery banks in bulk. If the Kinetik is comparable, I'd save a few hundred $$

this review tells a little more about it.

http://www.soundsolutionsaudio.com/forum/index.php?/topic/29499-kinetik-kcib12-35-battery-charger-review/

 

[TnT_Sounds 10+ year member]

good info i suppose.. thanks //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Savag3 10+ year member]

If you do not have a load tester seeing if the battery will take a charge and then testing it out by starting the vehicle isn't bad, especially if you start it up 3 times shut it off and come back to it 15 or 20 minutes later and do the same thing. If it gets weak or noticeably weaker after being fully charged on the charger you more than likely have a bad or sulfated battery. If it passes this test then gets weaker as the vehicle runs more than likely you have a wiring issue or a bad alt. I have 2 cheap load testers (led type) one will read that a battery is fine even though it is not even strong enough to start a car. I also have access to a dialed carbon pile load tester. To really see the condition of the battery you would actually have to cycle the battery and test its discharge and recharge capabilities. If you take the battery to autozone to be load tested you would have to make sure the guy running the load tester actually knows what he is doing as I have seen them call good batteries bad and bad batteries good (be it an agm or flooded battery) and I would venture to say the data gathered wouldn't be that specific. Also 12.6 volts on a flooded battery is only around 90% charged. Agms would read more like this:"Voltage at DOD

Here are some typical voltages vs. depth of discharge: (figured at 80% max discharge)

1% = 12.91 Volts.

10% = 12.8

20% = 12.66

30% = 12.52

40% = 12.38

50% = 12.22

60% = 12.06

70% = 11.90

80% = 11.70

90% = 11.42

100% = 10.50."

A load test can/will tell you if the plates are damaged IF it is done right. If the battery comes off an intelligent agm charger not holding anymore than 12.6v I would come to the hypothesis say it has some plate damage. Mine as we speak is resting at 12.78v and it has not seen a charger in months. Typically the manufacturer will tell you it is ok to put the battery in if it rests at 12.5v or above but from that standpoint the alt should charge it up to the 12.7 range at least. If the battery has sulfated plates you can cycle it on a charger that has a desulfate setting like this. http://www.sonicelectronix.com/item_13271_Kinetik+KIBC12-35.html

very informative , thank u