Deep batts won't hold charge...

[sharkman]

So I got 4 used odyssey group 31 batts from a member here a few months ago. When I go the batts I went to autozone and 2 of the batts didn't pass there load test. I was told buy the seller that there get doesn't work on deep cycle batts. So I took them home and left them on the charger for a few days. Well it's been a few months and 2 of the 4 batts are in my truck. I only need one but I wanted to do some install related since I really don't have and money or equipment to work with. I was trying to start and old car I have using one of the batts. And it was dead. Then I tried the other same thing..

..if the batts are good shouldn't they be able to hold charge only after a few months?..

Maybe I should look for new batts?

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[Papermaker85 5,000+ posts]

deep cycles are not starting batteries and they don't really work good for car audio nether. chances are they have a bad cell. i wouldn't even waste my time on them if they sat discharged for a while

 

[sharkman]

This the batt I have. I got 4 of them

http://www.odysseybatteries.com/batteries/pc2150s.htm

 

[Papermaker85 5,000+ posts]

i don't care what anyone say or about its rated CA. deep cycles are made for low current long discharge times. the cells are much large so the ESR is much higher. discharging the quickly isn't good for them and they take alot longer to recharge. this causes them a shortened lifespan. they aren't meant to be used in a dynamic application like car audio.. you could use them inline with a nice cap be to keep the caps topped off but other than that its just not idea brother.

this battery has a fairly low ESR and a much better starting ability while still have a longer cycle life than your typical starting battery.. this thing is dam strong for the money..

Duralast Platinum/Battery 31-AGM - Read Reviews on Duralast Platinum #31-AGM

ive used a few batteries and this one really is up there with the kinetik and XS power batteries..

 

[adulbrich 5,000+ posts]

If a battery can't hold a charge, it's junk.

What kind of tester did they use?

With the type we have, there's a general rule of thumb for under-hood batteries we go by in the shop.

A good battery load tests 400+ amps

A dying battery is around 350. We ask the customer if they'd like to replace it now or in a week

Anything under 300 amps, we strongly recommend replacing.

This is just a rule of thumb, and obviously you use some estimation judgement for larger or smaller batteries.

If those group 31's you have don't load test over 400, I'd say they're junk.

 

[sharkman]

If a battery can't hold a charge, it's junk.
What kind of tester did they use?

With the type we have, there's a general rule of thumb for under-hood batteries we go by in the shop.

A good battery load tests 400+ amps

A dying battery is around 350. We ask the customer if they'd like to replace it now or in a week

Anything under 300 amps, we strongly recommend replacing.

This is just a rule of thumb, and obviously you use some estimation judgement for larger or smaller batteries.

If those group 31's you have don't load test over 400, I'd say they're junk.

I had them tested at autozone the day I got them. The seller told me that just charged them. But a few didn't pass autozone batt tester. I went home and charged them with a motorcycle charge which he told me would work. I have have 2 chargers and not sure which one I should use. From what I'm reading they should have been cycled on the charger once a week. I will do some more reading

 

[1LOUDRT 10+ year member]

Keep in mind when charging AGM batteries like Odyssey or northstar that your charger needs to compatible with AGM batteries. Most will have a specific charge setting just for AGM types. They are absorbed glass matt which is much different than your normal lead acid or gel type battery. Good luck

 

[sharkman]

If a battery can't hold a charge, it's junk.
What kind of tester did they use?

With the type we have, there's a general rule of thumb for under-hood batteries we go by in the shop.

A good battery load tests 400+ amps

A dying battery is around 350. We ask the customer if they'd like to replace it now or in a week

Anything under 300 amps, we strongly recommend replacing.

This is just a rule of thumb, and obviously you use some estimation judgement for larger or smaller batteries.

If those group 31's you have don't load test over 400, I'd say they're junk.

I believe the batts are still good just needs to be charged a bit. They both read 11.8 and that's after sitting for about 4 months...I'm going to pop them on the charger and make sure I try to cycle them on and off every week or so

 

[Papermaker85 5,000+ posts]

I believe the batts are still good just needs to be charged a bit. They both read 11.8 and that's after sitting for about 4 months...I'm going to pop them on the charger and make sure I try to cycle them on and off every week or so

trickle charge them VERY SLOW. then if the hold above 12.2 install them.. you really cant tell though untill you put a load on them and calculate dischage rate/power

 

[adulbrich 5,000+ posts]

I had them tested at autozone the day I got them. The seller told me that just charged them. But a few didn't pass autozone batt tester. I went home and charged them with a motorcycle charge which he told me would work. I have have 2 chargers and not sure which one I should use. From what I'm reading they should have been cycled on the charger once a week. I will do some more reading

If it's a manual charger for standard batteries, there's a possibility that they were damaged, but that's unlikely. I'd be surprised if a motorcycle battery charger hurt a group 31 AGM

Sitting for a long time isn't good for batteries, especially if it's in the discharged state.

When they tested bad, you should've done more with the seller, if the batteries were junk.

 

[sharkman]

If it's a manual charger for standard batteries, there's a possibility that they were damaged, but that's unlikely. I'd be surprised if a motorcycle battery charger hurt a group 31 AGM
Sitting for a long time isn't good for batteries, especially if it's in the discharged state.

When they tested bad, you should've done more with the seller, if the batteries were junk.

But the numbers are good right 11.8 after 3-4 months? I did talk with the seller. I charged them and let them sit for about a week and they held the charge...i was thinking they would have read 10. Something. The first time I charged them was with the motorcycle charger. But yes the the other charger has a deep cycle option

 

[Papermaker85 5,000+ posts]

But the numbers are good right 11.8 after 3-4 months? I did talk with the seller. I charged them and let them sit for about a week and they held the charge...i was thinking they would have read 10. Something. The first time I charged them was with the motorcycle charger. But yes the the other charger has a deep cycle option

Load testing that's all you can do it's not really hard to make a load test you can get A5 gallon bucket of salt water and two pieces of metal measure the resistance between the two pieces of metal metal the deeper you submerge the less resistance they should have between the two plates bam you have a resistor Bank

 

[adulbrich 5,000+ posts]

But the numbers are good right 11.8 after 3-4 months? I did talk with the seller. I charged them and let them sit for about a week and they held the charge...i was thinking they would have read 10. Something. The first time I charged them was with the motorcycle charger. But yes the the other charger has a deep cycle option

I don't think 11.8 is good. Does that mean they're bad? No, but I leave batteries sitting at 12.6ish

 

[sharkman]

I don't think 11.8 is good. Does that mean they're bad? No, but I leave batteries sitting at 12.6ish

? Are you saying that if the batt reads 12.6 you don't mess with them or is that the volts you charge to? I apoly, don't really understand the statement

 

[adulbrich 5,000+ posts]

? Are you saying that if the batt reads 12.6 you don't mess with them or is that the volts you charge to? I apoly, don't really understand the statement

Letting batteries sit in the discharged state for a long time isn't great for them. When I let batteries sit, I make sure they're fully charged first. They get put on a tender at least once a month too. Lowest I'd let them sit at is 12.6v is what I meant.

I'm bringing some year-old Exide group 49's to Springfest. Load test like new and have been expertly maintained. Normal price is $180. I've got five of them. My bottom dollar is $100 each and not a penny less. Also have an extra C&D I'd sell.

I wouldn't want to ship batteries though. Too expensive. Otherwise, I'd hook you up.