How do I condition an AGM battery?

fla_cracker

Observer
Hilldweller,

Thank you for the offer. Atlanta is usually on the route out of Florida no matter where your going but.....no plans to be that way anytime soon.

Although during the fall I might hit you up for some places to go in Georgia.
 

Hilldweller

SE Expedition Society
I don't have am Optima, but my fully charged resting voltage for my Odyssey's is 12.8

+1 for the CTEK as well. I have used mine with great results many times on old batteries others cobsidered garbage.
I've had a bunch of batteries through the years and quite a few Optimas. Only one made by Enersys (they make Odyssey). I had the DieHard Platinum group 31 marine and it behaved more like a deep cycle like yours and only charged to 12.8v. That's common for a flooded deep cycle.
My Optimas all rested at 13.1 like clockwork.

I've got a number of chargers but only two that I use on the bigger batteries. My Optima cranks out a very smart 12 amps and my trusty old Sears charges at 10; they're both multi-battery variety. Even my solar charger is 5.6 amps and can be set specifically for type of battery, amperage, etc. Slick.

CTEK is a good charger. I'd personally want more amperage but there's nothing wrong with it. Just a little slow.


Hilldweller,

Thank you for the offer. Atlanta is usually on the route out of Florida no matter where your going but.....no plans to be that way anytime soon.

Although during the fall I might hit you up for some places to go in Georgia.
C'mon up. We're always doing something.
 

2.ooohhh

Active member
My cteks have pulled far more batteries back from the brink than many here would likely believe paying for themselves several times over. I routinely deal with vehicles that have sat for years upon years and since acquiring my first ctek nearly a decade ago I have replaced ALL my chargers and maintainers with cteks.
 

Pathfinder

Adventurer
I recently realized I apparently left an interior light on in my Tundra for several weeks, and the battery was really, really dead. Less than 9.8 volts. This is an OEM battery that was new in mid- 2010.

I connected it to my CTEK 7002, not really expecting much success, but a day later, voila, 12.8 volts. Runs like new. I use it power my Engle fridge/freezer on a recent trip in northern California. The battery seems as good as new.

My CTEK also also recovered an Optima that I was sure was a goner, but I have used it for years since I got my CTEK on a suggestion here on Expedition Portal several years ago.

Like other posters have stated, it has paid for itself over and over. It can be slow if the battery is really flat, but it can resurrect some that seem totally lost too.
 

sovereign

Observer
PHP:
I don't think much of a charger that only puts out 7 Amps. 8 stage charging? looks like 4 stage with some invented names in between.

Agreed. Per Odyssey, and other threads on this and other forums, a Diehard Platinum PM-1 sized battery needs a 50 amp charger. Why is this CTEK 7.2 amp charger receiving so many recommendations? I have a NOCO 7200 (7.2 amp) that is worthless for charging DH Platinums.
 

tweeek

Observer
PHP:

Agreed. Per Odyssey, and other threads on this and other forums, a Diehard Platinum PM-1 sized battery needs a 50 amp charger. Why is this CTEK 7.2 amp charger receiving so many recommendations? I have a NOCO 7200 (7.2 amp) that is worthless for charging DH Platinums.
Because it works.

I have never heard of anyone who has used one complaining about insufficient charging amperage, myself included.

I know what the specs say, I still sleep well at night.
 

DiploStrat

Expedition Leader
Speed is Money,

How fast do you want to go?

This chart tells it all: http://www.odysseybattery.com/ultimizer.aspx

Basically, high current is important during the bulk or boost stage, getting to 80% or better. After that, the actual current required is much lower and the key element is time.

So a 10A charge rate from your engine while driving for three hours doesn't get you much. But from a bench charger, run overnight (or from a shore power inverter/charger, run overnight), it will be fine because it will sustain that high voltage (14.7v) until the battery completes the acceptance/absorb stage. Remember too that within limits, voltage and current can be exchanged. That is why European appliances, running at 220v require only half the current of US appliances at 110v.

And with a proper three stage profile, these chargers are much better than the old dumb chargers which typically did not have enough voltage to charge very fast and then had too much current to float the battery, running the risk of boiling the thing dry.
 

wrcsixeight

Adventurer
99% of people have no idea what is going on inside a battery. It works until it does not. If a battery has only 80% of the original capacity, and the user only needs 50%, they have no idea that the other 20% is gone. They might even brag how the battery is still like new.

If the battery manufacturer says that reaching a 40% charge rate is paramount to get the heavily depleted battery upto maximum energy density for maximum performance and longevity, and someone using a charger rated at 1/6 the recommended amperage on this battery, only means the battery has not failed yet in such a recharge regimen.

If testing were done between two Odyssey batteries, one charged from 50% to 100% by a 7 amp charger, and one charged to 100% by a 40 amp charger which meets the 40% until 14.7v, hold 14.7for 4 hours regimen, which battery do you think is going to hold a higher voltage during the same discharge loading? Do the same test over and over for 50 cycles, and see how well the 2 compare during a load test. One battery is going to perform very well, the other's voltage will sag significantly further.

Have all the faith you want in any well marketed battery charger. If it does not meet the manufacturer recharge recommendations as to initial bulk current, or reach the absorption voltage setpoint, battery performance and longevity is going to be attenuated to some degree or another.

The more an Odyssey is depleted, the more important it is that it receives this 40% rate, or higher. If only cycled to 80% state of charge, then not meeting this 40% rate will not be so detrimental.

Lesser amp chargers can still restore a Odyssey back upto maximum energy density if the charger can bring the battery slowly upto 16.5v with very low currents that will not create enough pressure to pop the vents. This takes a lot of time and precise current control, and temperature compensation.

Obviously, or perhaps not, nothing should be attached to a battery that is brought upto 16.5V, besides the charging source itself.
 

tweeek

Observer
If the battery manufacturer says that reaching a 40% charge rate is paramount to get the heavily depleted battery upto maximum energy density for maximum performance and longevity, and someone using a charger rated at 1/6 the recommended amperage on this battery, only means the battery has not failed yet in such a recharge regimen.

I guess my batteries are never "heavily depleted" as I never drain them below 50%.

I suppose I must be part of your 99% of idiots out there. Im just sharing my personal experience. Do you own one of these chargers? I do, and it has served me well. Maybe it doesnt meet Odysseys specifications to bring back an Odyssey battery from the dead, for best performance, but for the majority of users out there, I am betting a 50 amp charger is way overkill.

I will use the $200 I saved on the charger and buy another battery when mine explodes in magnificent fashion , which may be tomorrow by the sounds of your analysis.

Again, this is just my experience.
 

Hilldweller

SE Expedition Society
99% of people have no idea what is going on inside a battery. It works until it does not. If a battery has only 80% of the original capacity, and the user only needs 50%, they have no idea that the other 20% is gone. They might even brag how the battery is still like new.

If the battery manufacturer says that reaching a 40% charge rate is paramount to get the heavily depleted battery upto maximum energy density for maximum performance and longevity, and someone using a charger rated at 1/6 the recommended amperage on this battery, only means the battery has not failed yet in such a recharge regimen.

If testing were done between two Odyssey batteries, one charged from 50% to 100% by a 7 amp charger, and one charged to 100% by a 40 amp charger which meets the 40% until 14.7v, hold 14.7for 4 hours regimen, which battery do you think is going to hold a higher voltage during the same discharge loading? Do the same test over and over for 50 cycles, and see how well the 2 compare during a load test. One battery is going to perform very well, the other's voltage will sag significantly further.

Have all the faith you want in any well marketed battery charger. If it does not meet the manufacturer recharge recommendations as to initial bulk current, or reach the absorption voltage setpoint, battery performance and longevity is going to be attenuated to some degree or another.

The more an Odyssey is depleted, the more important it is that it receives this 40% rate, or higher. If only cycled to 80% state of charge, then not meeting this 40% rate will not be so detrimental.

Lesser amp chargers can still restore a Odyssey back upto maximum energy density if the charger can bring the battery slowly upto 16.5v with very low currents that will not create enough pressure to pop the vents. This takes a lot of time and precise current control, and temperature compensation.

Obviously, or perhaps not, nothing should be attached to a battery that is brought upto 16.5V, besides the charging source itself.
Nicely said.
And exactly how I killed a DHP and two Optimas....
 

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