NOCO Genius 1 Poor Tempurature Compensation

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744
Location
Indiana
I have a NOCO Genius 1 I use Occasionally and I put it on our tractor that I normally run a battery minder on. The tractor is in an unheated garage, temperature this morning was 18°f this morning out there. The float voltage was sitting at 12.91v, which I give the charger an A for effort, however it was far below what it should have been. The charger was indicating it was in maintenance mode. I should mention this tractor battery is under 2 years old and has almost a perfect internal resistance reading. There is no draw what so ever on the battery.

I hooked my Battery minder 2012 up and sure enough it did its thing and I checked it an hour later and it was floating along nicely at 13.95 Volts.

The Battery minders with temperature compensation have the temp sensor outside the device, the NOCO Genius 1 supposedly has temperature compensation and the sensor is inside the device. I can only assume that the heat generated from the transformer inside the device effects the ambient temperature sensor inside the device and there is not correct internal compensation, or the programing of the logic does not continually hold float voltage at the maximum allowable voltage for the corresponding temperature and this is by design and part of the Genius working its magic, or the float voltage simply is not as high as on the battery minder, which doesnt make sense and would create its own issues.

I cannot find any information in the NOCO manual on the charging algorithm like I have found in battery minder or Ctek manuals.

I am going to run a few more experiments and see what we find. The Battery Minders have been my favorite thus far, I have several and they are top notch in my book. I do like that my NOCO 5 has a "repair" mode that runs the voltage up high and gives the battery a nice equalizing charge, which is why I bought that particular one to begin with.
 

JHZR2

Staff member
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46,391
Location
New Jersey
I would not call the NOCO Genius charger a “float” charger. Based upon my use of them versus battery minders, I’ve observed what you do.

It “floats” the battery for some time, then turns off the charger and just samples the voltage. After it gets to a certain voltage, it repeats the process.

I need to put my sampling multimeter on it to verify the behavior. Just what the range is... But it does vary the voltage based upon ambient. But I don’t think you’re seeing anything abnormal.

The battery minder does truly float the battery at a temperature compensated value. Some argue doing so results in an elevated corrosion rate. But that said, AGM batteries in standby use in climate controlled locations can see 10+ years of life...
 
Messages
4,679
Isn't the float voltage on these somewhere around 12.5V? Or am I mistaken.

I know about CTEK not NOCO. In Stage 7, it delivers 13.6V (I've measured mine delivering 13.74-13.75V) until 10 days after the moment you connected it, then it goes to Stage 8. Which may be where the 12.x comes in...
 

JHZR2

Staff member
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46,391
Location
New Jersey
Depending upon ambient, the open circuit (bare terminals, completely unloaded) voltage at 100% SOC is between ~12.5 and 12.7V.

Float voltage is around 13.5V with variation based upon temperature.

Stage 8 for the creek sounds a lot like what I think OP is seeing - drop the voltage to further reduce gassing and corrosion, watch for voltage drop, then top off when needed.
 
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4,679
Depending upon ambient, the open circuit (bare terminals, completely unloaded) voltage at 100% SOC is between ~12.5 and 12.7V.

Float voltage is around 13.5V with variation based upon temperature.

Stage 8 for the creek sounds a lot like what I think OP is seeing - drop the voltage to further reduce gassing and corrosion, watch for voltage drop, then top off when needed.
Yep! Stage 8 will only charge again if the battery dips below 95% charge. (Which of course it probably won't.)

My car has sat for about two weeks but should be fine. That little overcharge, if there was any and there maybe was, sure helped.
 

5AcresAndAFool

Thread starter
Messages
744
Location
Indiana
Isn't the float voltage on these somewhere around 12.5V? Or am I mistaken.

I know about CTEK not NOCO. In Stage 7, it delivers 13.6V (I've measured mine delivering 13.74-13.75V) until 10 days after the moment you connected it, then it goes to Stage 8. Which may be where the 12.x comes in...
Good question, I cant find the spec anywhere, The battery is 12.5 at rest so the 12.9 would make sense in this cold, however that's way too low to keep the battery fully charged, unless it periodically applies a higher charge rate to the battery.
 

JHZR2

Staff member
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46,391
Location
New Jersey
Good question, I cant find the spec anywhere, The battery is 12.5 at rest so the 12.9 would make sense in this cold, however that's way too low to keep the battery fully charged, unless it periodically applies a higher charge rate to the battery.
The spec should be provided, though I too haven’t found it.

Reality is though that float and 100% are both temperature related. So the spec would really be x.yz V +/-n mV/deg C, or something like that.

As noted before, these chargers seem to rest after a while and don’t keep a permanent float voltage. I am curious what the threshold value is to turn the charge back on, and when it’s invoked, does it merely bring the battery up to a “float” voltage, or does it take it all the way back to 14.x V and watch for the current to decay to a certain level?
 
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4,679
The spec should be provided, though I too haven’t found it.

Reality is though that float and 100% are both temperature related. So the spec would really be x.yz V +/-n mV/deg C, or something like that.

As noted before, these chargers seem to rest after a while and don’t keep a permanent float voltage. I am curious what the threshold value is to turn the charge back on, and when it’s invoked, does it merely bring the battery up to a “float” voltage, or does it take it all the way back to 14.x V and watch for the current to decay to a certain level?
Stage 7 holds at 13.6V (though I have measured mine at 13.75V, probably because.. it's cold outside) for 10 days. Not sure what it was after that but it was like 12-something I think.

I'd have to get a battery and leave it on and check it LOL. I just may!
 

JHZR2

Staff member
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46,391
Location
New Jersey
@JHZR2 Can you explain what float voltage is and why it's important?
Sure.

I think it’s first important to recognize a few things:
1) a connected battery will face some level of parasitic load, including from internal self-discharge.

2) A battery’s state of charge can be correlated to its voltage, which is the sum of the electrochemical potentials of the half cells (anode and cathode). These vary slightly based upon the alloys, pastes and other active chemical components in the battery, as well as temperature.

#1 is important because it means that batteries are always self discharging. Lead acid batteries (including flooded and VRLA/AGM) need to stay at exactly 100% for max life. A tiny bit more, and degrading corrosion occurs. A tiny bit low and sulfation occurs. #2 is important to realize that since the industry and end users lack configuration control, Thus the absolute truth on the absolutely correct voltage at temperature to define as 100% is variable. Thus everything else must be assumed to have a bit of error.

Float (or trickle, which is sometimes used interchangeably), is the elevated voltage level that provides an “equilibrium”. That is, where after a proper charging profile to 14.4/14.7V, the voltage is reduced to a level where any parasitics (self discharge) is offset at effectively a net zero level. Because there are electrochemical “activation” losses in charging, it takes a little bit of a voltage boost to squeeze the electrons in.

So float is a “lossless” interface (calling it an interface vs a voltage because it needs to be applied, it doesn’t naturally happen to be that high), or at least in theory. If the float voltage was kept exactly right for the battery chemistry and temperature, the battery would stay at 100%. Practically speaking, a battery connected to anything are a parasitic, regardless of light loads. The battery itself is a parasitic, see #1. Thus to have true and ideally maximum capacity and capability from a battery, you want it sitting at float.

There are two schools of thought though:
a) Float is never exact for any number of reasons, thus permanent “float” will result in some periods of corrosion and some periods of sulfation. This is because of #2 above. Thus prolonged float is causing some unforeseen damage, regardless of how small. You’re better off “fully” charging (which again is not an exact matter), and just topping up in a controlled way at some predefined voltage.

b) Since batteries are expected to provide max performance, float should be maintained, and a flag should be set if/when sustained current requirement goes too high. Any chance of damage or degradation is no worse than sitting at less than 100%.

I think I’d argue that if you have a true mission critical application, like a major backup power system or something like that, and max capability is required, permanent float charging is important. For vehicles, it’s such an inexact science, and battery replacement is favored to gain reliability, then getting in the ballpark to help gain longevity and offset losses is the best you can ask for. Thus why the NOCO/ctek approach is growing on me. Elevated voltages increase stress on electric components (like electrolytic capacitors on circuit boards). If after a prescribed duration on float, it shuts off and monitors, it should be good enough for a 3-10 year replacemebt cycle on the battery, and be easier on other electronic components, even if just marginally.

Let me know if you have questions.
 

wwillson

Staff member
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3,991
Location
Naperville, IL
Thank you for your explanation!

If only we would have known this when I was growing up. We left most machines parked all winter and thought it was ok to charge the dead batteries in the spring or late summer and all would be good. Most machinery batteries only lasted about 18 months, when there was no reason the services life could have been 5 years. Thousands of dollars of batteries wasted.
 
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4,679
Thank you for your explanation!

If only we would have known this when I was growing up. We left most machines parked all winter and thought it was ok to charge the dead batteries in the spring or late summer and all would be good. Most machinery batteries only lasted about 18 months, when there was no reason the services life could have been 5 years. Thousands of dollars of batteries wasted.
I wonder if the companies thought they were "wasting" the electricity to charge a "fully charged battery!" 🔋
 

4WD

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17,315
Location
Texas
I wonder if the companies thought they were "wasting" the electricity to charge a "fully charged battery!" 🔋
Sometimes it’s not economics but safety … boat storage I used sent us all a letter that they were cutting power take it or leave it. Reason was a fire started by a charger left on a boat battery …
Left boat there for a few years longer turning off the Perko switch + battery bought based on 3 yoa
 
Messages
4,679
Sometimes it’s not economics but safety … boat storage I used sent us all a letter that they were cutting power take it or leave it. Reason was a fire started by a charger left on a boat battery …
Left boat there for a few years longer turning off the Perko switch + battery bought based on 3 yoa
I believe it, though I can't tell you how many times temps have left the heater on in a warehouse I used to work at all weekend .. surprised they didn't start a fire. Of course you could say there was nowhere for the fire to travel to, once it started, being mounted away from the ceiling but..

Okay, heat is not electricity, but I would wonder if that charger was an old "dumb" charger.
 
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4,679
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Messages
4,679
As to CTEK, which parallels NOCO.. I just measured 13.93V on battery at Stage 7. Not disconnected since previous pics.

I know I should take the protective cover off the screen, but I just can't bring myself to do it lol.
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Messages
876
Location
sw ohio
I would not call the NOCO Genius charger a “float” charger. Based upon my use of them versus battery minders, I’ve observed what you do.

It “floats” the battery for some time, then turns off the charger and just samples the voltage. After it gets to a certain voltage, it repeats the process.

I need to put my sampling multimeter on it to verify the behavior. Just what the range is... But it does vary the voltage based upon ambient. But I don’t think you’re seeing anything abnormal.

The battery minder does truly float the battery at a temperature compensated value. Some argue doing so results in an elevated corrosion rate. But that said, AGM batteries in standby use in climate controlled locations can see 10+ years of life...
JHR2-
I got that NOCO Genius 1 recently and fullly charged green indicator light never periodically goes off to indicate battery is entering maintainer mode. To check, I installed my Shumacher and its green light goes off to indicate battery is fully charged and periodically lights up to indicate maintainer charge. Voltage readings also show full charge. This is an almost new Deka AGM top of the line battery installed in my seldom driven garage queen.

Does your NOCO exhibit this behavior suggesting mine is faulty? I can still send it back.

FiveAcres, good call on the temperature compensation from internal sensor
 
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