CTEK + Odyssey = New Charger

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In the first quarter of 2024 EnerSys (Odyssey) will have a new series of chargers designed and manufactured by CTEK that they claim will "transform the battery charging landscape". Odyssey's recommendation for optimum charging current is 40% of the battery's C10 rating (i.e. 40 amps for a 100Ah battery). But the new charger series will top out at 25A. Right out of the gate, the new chargers are short on current output for the larger Odyssey batteries.


....The new series of chargers will become a part of the ODYSSEY® battery charger portfolio and are designed to efficiently charge a variety of ODYSSEY®battery models as well as other quality brands of Absorbed Glass Mat (AGM) flooded lead acid and lithium batteries. Engineered with built-in temperature controls and a battery status indicator, ODYSSEY® battery chargers will be available in the European Union (EU), United Kingdom (UK) and North American markets (USA and Canada) in 5A, 15A and 25A variants...
 
Probably the reason for the lack of a larger charger option is they realize most of their customers are not running the battery that far down that is would require it. The great majority simply need a maintainer.

Also they confusingly recommend the Schauer 1/8/12 amp charger as sufficient for 7-114ah Odyssey batteries.
In the ad script it states:
  • Approved for use on these Odyssey batteries: PC925, PC925L, PC925LMJ, PC925MJT, PC950

 
The duration of time that these batteries would accept 25 or 40A without hitting a voltage limit is probably pretty small. When I run an ammeter on a 1
25A ctek, it starts naturally dropping current for a given voltage pretty quick.

While the 40% thing sounds good, I’m not sure it truly is good for the battery, nor is it a sustained current level.
 
The Odyssey 2021 technical manual recommends a "optimum" charging current of at least 40% of C10 rating.

Screen Shot 2024-01-29 at 11.13.23 AM.png
 
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Odyssey also wants their batteries when float charged at 13.6vt to temperature compensate higher voltage when colder and lower when warmer. What is interesting is in my testing I noted the 77F float voltage is closer to 13.4vt with Battery Minder, even though they are on the "approved" list from Odyssey. It then compensates by temperature higher or lower from the 77F 13.4vt charging mid point. I questioned Battery Minder about this, and they said they changed their algorithm and 13.4vt is correct. They found customers with Odyssey and other AGM were experiencing damaged batteries from signs of overcharging with the original 13.6vt mid point.
 
Odyssey did reduce temperature compensation to 18mV per degC in the latest manual, for the 2nd generation batteries. In the earlier tech manual, the spec was 24mV.

Screen Shot 2024-01-29 at 4.44.49 PM.jpg
 
The Odyssey 2021 technical manual recommends a "optimum" charging current of at least 40% of C10 rating.

View attachment 200750
That’s great but it doesn’t mean they’ll take current exactly like the graphic shows. IME the voltage increase happens rapidly, then it holds and the cv mode kicks in. So the time at cc may be low.
 
High current when charging a VRLA battery, even for a short duration, can be beneficial for increasing cycle life . I assume this is why Odyssey engineers recommend it.

Given these findings, and work already carried out in the ALABC program (3), we feel that a proper charging algorithm for VRLA batteries involves the following:
  • • High inrush currents to promote nucleation, thus maintaining a fine, open pore structure.
  • • No limitation on the percent overcharge (although, with proper charging and termination,
    this should never exceed ~20%).
  • • A modest-to-high rate of charging to provide current to the battery fairly rapidly, particularly at the beginning and end of charge.
  • • High finishing currents to provide enough charge for the recombination cycle and still have some available to finish charging the active materials.
  • • An effective charging termination point that completely recharge the active materials with minimal overcharge and compensates over the battery lifetime for the increasing influence of oxygen recombination.
The above quote is from a National Renewable Energy Laboratory research paper.

 
I had temperatures around 25F in my garage a couple weeks ago and my bluetooth monitor stated my Battery Minder AGM charger was floating at 13.80vt during that time. It is now around 56F and floating at 13.54. The battery is an Interstate Group 48/H6 AGM.
What is the upper limit for float on an Odyssey?
 
.....What is the upper limit for float on an Odyssey?
Odyssey says the acceptable range for float voltage at 77F is 13.5V -13.8V, with 13.6V being optimal. The optimal float voltage at 30F would be 14.07V , and the upper limit would be 14.27V. The calculated voltages at 30F are based on a temperature coefficient of 10mV per degF (18mV per degC) and a reference temperature of 77F.
 
High current when charging a VRLA battery, even for a short duration, can be beneficial for increasing cycle life . I assume this is why Odyssey engineers recommend it.


The above quote is from a National Renewable Energy Laboratory research paper.

So how long is an inrush? A quarter cycle at 60Hz? A second?

What is a moderate to high charge rate?

Again, you can’t push what it can’t take. You could put a 1000A supply on it, if the max voltage is reached, the current will start to drop.
 
Odyssey says the acceptable range for float voltage at 77F is 13.5V -13.8V, with 13.6V being optimal. The optimal float voltage at 30F would be 14.07V , and the upper limit would be 14.27V. The calculated voltages at 30F are based on a temperature coefficient of 10mV per degF (18mV per degC) and a reference temperature of 77F.
Thanks...actually I am looking at the screen shot from my bluetooth battery monitor and it peaked at around 13.87vt when temps were in the mid to upper 20's in my garage. Battery Minder AGM with automatic temperature compensation
 
Weird that there is a requirement for an approved AC charger. That's what the alternator is for. Or jumper cables, when necessary. worst case a trickle charger for long parked periods, but a high current AC Charger? Why?
 
Weird that there is a requirement for an approved AC charger. That's what the alternator is for. Or jumper cables, when necessary. worst case a trickle charger for long parked periods, but a high current AC Charger? Why?
Odyssey has no mandatory requirement for external charging, alternator charging is fine. An alternator can easily supply high current immediately after startup.The high current usually tapers down quickly, within a minute, unless the Odyssey is deeply discharged. If you want to use an external charger, high current is not mandatory, it is recommended, especially if the battery is deeply discharged.

Charging with an Alternator
When used in starting applications, ODYSSEY® AGM2 12V batteries will be charged on-board using a standard automotive alternator that generates anywhere between 14.2-14.5V at 77F (25C). We recommend a temperature compensation of the charge voltage at ±18 mv per battery per degC variation in temperature from 25C. The warmer the temperature the lower the charge voltage and the cooler the temperature the higher the charge voltage.
 
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Thanks...actually I am looking at the screen shot from my bluetooth battery monitor and it peaked at around 13.87vt when temps were in the mid to upper 20's in my garage. Battery Minder AGM with automatic temperature compensation
Looks like your BM charger is using a temperature coefficient (TC) of 10mV per degF and a reference temperature of 77F ?
My 6A Optimate charger has a TC of 13.3mV per degF, with a reference temperature of 68F.
My 20A Pro-Logix charger has temperature compensation, but there are no TC specs provided in the owner's manual or sales literature.
 
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Weird that there is a requirement for an approved AC charger. That's what the alternator is for. Or jumper cables, when necessary.........
An alternator is a bad choice for charging a nearly dead battery.


Jumper cables can be a lifesaver, literally! However, when you use jumper cables to start your vehicle, you are placing a tremendous strain on your vehicle's alternator and battery. That is why we recommend fully-charging deeply-discharged batteries with a battery charger as soon as possible.

Alternator manufacturers know the same things about alternators that we do- they are designed to maintain batteries that are near a full state of charge, not recharge deeply-discharged batteries. We post this on message boards and in groups all the time, but there are still folks who are convinced their alternators are designed to recharge deeply-discharged batteries. We know this, because they call our tech support lines on a regular basis, because their battery keeps getting deeply-discharged (it is actually just staying deeply-discharged). The alternator manufacturers also get calls from these folks, because they've burned up their alternators, trying to recharge deeply-discharged batteries.

Does this mean you should never use jumper cables to start your vehicle? Absolutely not! We carry them in all of our vehicles, in case of an emergency. However, when jumper cables are needed, be sure to get the battery fully-charged with a battery charger as soon as possible.
 
An alternator is a bad choice for charging a nearly dead battery.

I've had Ferrari service technicians comment about people with "garage queen" Ferraris that they jump all the time and end up flat bedding in for a new or rebuilt alternator. Probably why all Ferraris come with a battery tender standard from the factory since around 2003. They were optional prior to that. Even in the 1990s Ferraris started coming standard with a master battery cut off switch in the front trunk...but not convenient to use, as you lose your clock and radio settings each time, so people rarely used them.
 
I've had Ferrari service technicians comment about people with "garage queen" Ferraris that they jump all the time and end up flat bedding in for a new or rebuilt alternator.
an oddyssey isn't a ferrari. Having a factory recommended AC charger for a mainstream people mover still strikes me as odd. How often do you have a dead battery? I can count mine on my fingers in my 38 years of driving.
 
an oddyssey isn't a ferrari. Having a factory recommended AC charger for a mainstream people mover still strikes me as odd. How often do you have a dead battery? I can count mine on my fingers in my 38 years of driving.
I was commenting on the post of not using your alternator to charge a dead battery.
I have had a dead battery only a handful of times, but I take precautions.

Modern car batteries are subject to much higher parasitic electrical draw than before. If you don't drive them at least every three weeks and for at least a half hour or more, the batteries will not maintain enough charge to reliably start. Not a problem with a daily driver, but if you have multiple cars its a problem. I have three cars and a motorcycle, only one car is daily driven. Some don't get driven for a couple months. They would be dead with out a battery tender. So two of my cars, and my motorcyle are constantly on a battery tender.

If you have a battery tender and use it, agreed a HD battery charger would likely never be needed.
 
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