EDIT: CellLink Neo charging voltage 2-2.5V lower than car battery voltage

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My CellLink Neo has started to demonstrate low voltage warning when set to high (9A) charging while hardwired to the car.
I noticed that my car's voltage drops by 2.2-2.5V when charging the battery pack, triggering the low voltage warning.
I do not think the voltage drop was that much when it was first installed, but I do not recall.


Edit: Just realized I got my wording completely mixed up. Car voltage is fine, but when the CellLink Neo is set to draw 9A and charge via a hardwire in the fuse box, the charging voltage seen on the CellLink Neo is 2-2.5V lower than what the car battery is. This causes the low voltage error on the CellLink Neo app and stops it from charging.
When the battery is tested with other vehicles, there is only a 0.5-1V lower difference in the CellLink Neo voltage and car voltage, and it charges properly.
Also tried hooking up a brand new CellLink Neo battery, but having the same exact issues.

Dashcam/battery wiring has been tested and confirmed to be working properly, including ground points. New car battery installed too.

Any ideas as to why the voltage drop is significantly higher in my scenario?



Another piece of information: When using a wall socket adapter to charge at 12V/5A, the CellLink Neo displayed voltage is 11.5V and charges properly. The new CellLink Neo also demonstrated the same voltage when charging, so it seems the CellLink battery is not the issue.
 
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Is it only charging while the engine is running. 9amps on a modern vehicle is not much while the engine is running, but it is a lot when it isn't.

It will suck the life out of a small starter battery. Lithium will take anything they can get, as much as their controller, or a DC-DC charger between it and the starter battery.

A lot of cars these days have a pretty small starter battery to reduce weight so by the time you power the car's CANbus shutdown and startup process a few times, batteries can suffer.

My car has a 180amp alternator, new models 210amp alternator, the hi-fi alone has a few fuses, one of them 40amps. 85AH 800CCA battery. Most cars have smaller systems.
 
Yes, it is only charging when the engine is running. I previously had a 75Ah 800CCA battery that had no issues powering the battery pack for 1-2 years.
Only recently did I notice that the battery was no longer being properly charged and had the car battery changed out to a 95Ah 900CCA as the previous battery was starting to show signs of age.

I do not have any issues with other accessories (radio, lights, heating, etc), so I am leaning towards the alternator not being an issue.
 
Disconnect the Celllink for a few days and each day check the car's voltage.

Then you can narrow down the equation.
 
What circuit are you using to charge the cellink? Could it be that it is struggling to supply the required demand?
 
I do not have any issues with other accessories (radio, lights, heating, etc), so I am leaning towards the alternator not being an issue.
I had a similar issue, the alternator needed new brushes.

You should expect a small drop in voltage when taking 9A, 9 x 14 = 126W, which is more than most accessories, but if it is getting worse over time, and your car is a few years old and especially if it is inconsistent or connected with engine temperature, then the alternator brushes are quite likely the issue.

Any decent alternator should be able to provide 9A, no point in upgrading if it is just a brush issue.

It is also possible there is an earth cable with a poor connection, maybe connecting the engine to the body. This could result in the alternator seeing good voltage under high load while the rest of the car doesn't.
 
I run 3 air compressors in parallel for pumping up tyres quickly in the outback which draw a combined total of 90amps. The alternator doesn't flinch and stays at 14.4volts.

9amps while the engine is running is not an issue.
 
Disconnect the Celllink for a few days and each day check the car's voltage.

Then you can narrow down the equation.

Old battery condition was still well above what would warrant a replacement. Just barely on the cusp of maintaining 800CCA with good voltage after a couple weeks.
New battery is good.

What circuit are you using to charge the cellink? Could it be that it is struggling to supply the required demand?

Originally when everything was working well it was hardwired into the seat ventilation fuse. Tried a few others since then, including empty fuse slots. All have the same voltage drop.

I had a similar issue, the alternator needed new brushes.

You should expect a small drop in voltage when taking 9A, 9 x 14 = 126W, which is more than most accessories, but if it is getting worse over time, and your car is a few years old and especially if it is inconsistent or connected with engine temperature, then the alternator brushes are quite likely the issue.

Any decent alternator should be able to provide 9A, no point in upgrading if it is just a brush issue.

It is also possible there is an earth cable with a poor connection, maybe connecting the engine to the body. This could result in the alternator seeing good voltage under high load while the rest of the car doesn't.

Car is still under warranty, and just had a service where they said everything is working within specifications. Since I am not having issues with native accessories like displays, heating, headlights, etc., I do not think they can do anything about it. I would change the brush myself, but it is not my expertise.
How can I look for a faulty ground? Would it place a parasitic drain on the battery when the ignition is off, allowing me to pull fuses to find it, or is that something else entirely?
 
How can I look for a faulty ground? Would it place a parasitic drain on the battery when the ignition is off, allowing me to pull fuses to find it, or is that something else entirely?
Need a voltage meter, measure the voltage between a bolt on the engine (or preferably the metal frame of the alternator) and a bolt on the car body (or the battery negative terminal). It should be zero when the engine is stopped, a little above zero with the engine running, but if it is 2 volts higher then you have found your problem. Note that measuring a voltage off aluminium may not work since aluminum oxide does not conduct electricity even though it looks like metal.

You could also check the voltage across the alternator with the engine running, if you can get access to the terminals. On my car they are directly accessible with the bonnet open, but that may not be the case, and you need to be very careful of moving parts and dangerous voltages/currents, so leave it to an expert if you are not sure of what you are doing.
 
Old battery condition was still well above what would warrant a replacement. Just barely on the cusp of maintaining 800CCA with good voltage after a couple weeks.
New battery is good.



Originally when everything was working well it was hardwired into the seat ventilation fuse. Tried a few others since then, including empty fuse slots. All have the same voltage drop.



Car is still under warranty, and just had a service where they said everything is working within specifications. Since I am not having issues with native accessories like displays, heating, headlights, etc., I do not think they can do anything about it. I would change the brush myself, but it is not my expertise.
How can I look for a faulty ground? Would it place a parasitic drain on the battery when the ignition is off, allowing me to pull fuses to find it, or is that something else entirely?
If it’s the engine earth strap causing the voltage drop you should be able to measure it with a voltmeter. One probe on the engine block and one on the battery neg terminal.
it would be worth checking the voltage at a few places also to try and pinpoint of the drop is only at certain points.
I assume you were measuring the drop at the battery terminals?
you could try at the back of the alternator. If the car has the battery concealed and under bonnet jump points also check it there.
I assume the battery terminals are all tightened correctly and the earth lead is tight where it meets the body?
 
just had a service where they said everything is working within specifications.
I wouldn't put much faith in that!

Would it place a parasitic drain on the battery when the ignition is off
No, just means that when there is a heavy load and the engine is running, the alternator will think there is no need to provide more power because it is seeing a "fully charged" voltage. It could potentially result in the car battery being drained into the celllink while the engine is running, but if it was that bad then I think you would experience other issues, like the engine not running well.
 
Need a voltage meter, measure the voltage between a bolt on the engine (or preferably the metal frame of the alternator) and a bolt on the car body (or the battery negative terminal). It should be zero when the engine is stopped, a little above zero with the engine running, but if it is 2 volts higher then you have found your problem. Note that measuring a voltage off aluminium may not work since aluminum oxide does not conduct electricity even though it looks like metal.

You could also check the voltage across the alternator with the engine running, if you can get access to the terminals. On my car they are directly accessible with the bonnet open, but that may not be the case, and you need to be very careful of moving parts and dangerous voltages/currents, so leave it to an expert if you are not sure of what you are doing.
I measured the between the negative starter bolt under my hood to the alternator frame. When the car is off, 0.0V. When the engine is on, 0.023-0.050V.
I can see the 4 bolts that mount the alternator to the engine/bracket, but other than that I do not know which points to measure. It seems like based on above values that the ground is appropriate.

If it’s the engine earth strap causing the voltage drop you should be able to measure it with a voltmeter. One probe on the engine block and one on the battery neg terminal.
it would be worth checking the voltage at a few places also to try and pinpoint of the drop is only at certain points.
I assume you were measuring the drop at the battery terminals?
you could try at the back of the alternator. If the car has the battery concealed and under bonnet jump points also check it there.
I assume the battery terminals are all tightened correctly and the earth lead is tight where it meets the body?
Yes, the voltage drop observed when powering the CellLink Neo was observed at the battery terminals.
I verified the terminals and connectors were tightened and cleaned as well.
 
You need to measure the voltage at each connection to see where the 2 volts are being lost, could be the fuse, the fuse tap, the wiring to the fuse box, the wiring to the earth connection, the earth itself back to the battery...

Have you added any cable? In which case it may be the cable is too thin.
 
You need to measure the voltage at each connection to see where the 2 volts are being lost, could be the fuse, the fuse tap, the wiring to the fuse box, the wiring to the earth connection, the earth itself back to the battery...

Have you added any cable? In which case it may be the cable is too thin.
I have a 3 meter long 16 gauge wire added in to the hardwire charging cable. The CellLink Neo and extension cables were installed over a year ago, with no issues with charging until a few weeks ago.

I have an inline fuse in-between the CellLink Neo and fuse box. The measured voltage at either side of the fuse read the same voltage as what is measured at the car battery.
It is only the CellLink Neo voltage that reads low, there is nothing else between the inline fuse and CellLink Neo.
 
I have a 3 meter long 16 gauge wire added in to the hardwire charging cable. The CellLink Neo and extension cables were installed over a year ago, with no issues with charging until a few weeks ago.

I have an inline fuse in-between the CellLink Neo and fuse box. The measured voltage at either side of the fuse read the same voltage as what is measured at the car battery.
It is only the CellLink Neo voltage that reads low, there is nothing else between the inline fuse and CellLink Neo.
How long is the cable between the inline fuse and the Neo?

When you check the voltage at that fuse, are you using the same earth point as the Neo, or another earth point/battery terminal which may be at a different voltage to the Neo's earth?
 
If it is difficult to measure the voltage due to the design on the plugs & to avoid building an adaptor. One can stick a pin through the power cable as long as it has separate positive and negative wires, keeping the pins well apart so you do not accidentally short them.
 
The CellLink Neo and extension cables were installed over a year ago, with no issues with charging until a few weeks ago.
This indicates that something has changed. I'd scrutinize every connection for tightness and corrosion.

On the voltage tests do as Outback Nomad recommends, with a pin or needle pushed through the middle of the wires. Note the readings, then move the test lead to the connector ahead of it. If you get a substantially different reading then the problem is where wire meets connector. If possible do this while the Cellink is charging (under load).

My guess is that you're going to find the problem in the ground (earth) wire, connector, or in what it's attached to. It's very common for those connections to corrode or loosen over time.

Phil
 
How long is the cable between the inline fuse and the Neo?

When you check the voltage at that fuse, are you using the same earth point as the Neo, or another earth point/battery terminal which may be at a different voltage to the Neo's earth?
The distance is about 50cm.

When checking the voltage at the inline fuse, I am grounding at the negative battery terminal, which is different from the CellLink Neo (its grounding point is fairly inaccessible).
I decided to recheck the voltages after your comment just to be sure, and this time I noticed the voltage at the inline fuse is 1.0V lower than the car battery. The CellLink Neo charging voltage is a further 1.0-1.3V lower than that, resulting the over 2-2.3V lower reading than the car battery.
Does this mean somewhere between the fusebox and the inline fuse, there is a corroded connector or damaged wire? I always assumed that if there was a damaged wire that both amperage and voltage would be lower. However, during the first 1-2 minutes of car ignition when the car battery is being charged at 15.1V, the resultant 12.7-13.1V seen on the CellLink Neo allows proper charging at the full 9A. When the car battery settles down to 13.3V after the first couple minutes, that is when the CellLink Neo has the low voltage error (roughly <10.7V) and stops charging.
 
This indicates that something has changed. I'd scrutinize every connection for tightness and corrosion.

On the voltage tests do as Outback Nomad recommends, with a pin or needle pushed through the middle of the wires. Note the readings, then move the test lead to the connector ahead of it. If you get a substantially different reading then the problem is where wire meets connector. If possible do this while the Cellink is charging (under load).

My guess is that you're going to find the problem in the ground (earth) wire, connector, or in what it's attached to. It's very common for those connections to corrode or loosen over time.

Phil
I asked in the previous reply, but wouldn't a damaged/corroded wire or connector cause both amperage and voltage drops? The amperage draw on the CellLink Neo is stable during the first couple minutes of ignition.
 
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