Disable built in charger

[BigDean]

Hi all,

In our Adria Matrix we have the Nordelectronica NE237 controller which I understand quite well. I have installed a lithium battery which is okay. I have a feeling that whilst the NE237 has a GEL setting and the battery is a "drop-in" so is happy with 14.4v and 13.8v, it isn't charging fully. It was 13.8v as expected whilst on mains hook-up at home, but the after driving to a park-up yesterday, about an hour away, the battery was only showing 13.3v. Then whilst using last night and this morning, off-grid (no solar connected), the voltage seems to have INCREASED! See attached log.

If it is having a problem, what I would like to do is disable the charging on the NE237 and fit a Victron charger. As I already have the Victron shunt and Cerbo GX, this would make a lot of sense. So, does anyone know how you can disable just the mains charging on such a unit. I can't disable it altogether without a significant rewire of all the 12v systems.

The NE237 also keeps the cab battery topped up, so would need to take that into account for any solution, although could easily do this with a Votronics unit. Would also add an Orion B2B to charge the lithium faster than the built in one.

Appreciate your input as always

Thanks

 

[John H.]

Your setup seems to be working well.

What are you using to give the nice graph?

 

[BigDean]

Your setup seems to be working well.

What are you using to give the nice graph?

I was worried about the initial voltage drop, then it seemingly increasing, but if that is normal, happy days.

It is from VRM, the Victron Cloud portal. It is great for monitoring all sorts. 320w of solar going on with a SmartSolar MPPT in a few weeks which all links into it as well. As long as you have a Cerbo GX and WiFi, all is logged.

Thanks

 

[Guigsy]

I thought that voltage wasn't a good measure for Lithium batteries because the voltage-charge curve is so flat for most of the cycle?

What does the shunt say in terms of Ah?

 

[BigDean]

I thought that voltage wasn't a good measure for Lithium batteries because the voltage-charge curve is so flat for most of the cycle?

What does the shunt say in terms of Ah?

The SOC is a nice flat line, but it only calculates that from the usage, so no use. The Ah used is all reported correctly based on what we were doing.

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[autorouter]

It looks like it could be a measurement error. It definitely shows current flowing INTO the battery, when you say there are no possible charging sources connected. What exactly is connected to the battery side of the Victron shunt?

 

[BigDean]

It looks like it could be a measurement error. It definitely shows current flowing INTO the battery, when you say there are no possible charging sources connected. What exactly is connected to the battery side of the Victron shunt?

Just the battery!

Thanks

 

[autorouter]

Just the battery!

Definitely just the battery, not the ground wire too?

 

[BigDean]

Definitely just the battery, not the ground wire too?

From the negative side of the battery to the shunt, then from the shunt to ground/other negative cables. The smartshunt has 2 small positive connections, one to the leisure battery and one to the cab battery.

There is nothing that could cause a charge. There is no solar connected currently, the engine was off and we were not hooked up.

Mysterious.

The NE237 does manage both the cab and leisure battery, possibly allowing a current through from the cab battery acting as a B2B?

Wouldn't have thought so, but cant think of anything else.

 

[cmcardle75]

From the negative side of the battery to the shunt, then from the shunt to ground/other negative cables. The smartshunt has 2 small positive connections, one to the leisure battery and one to the cab battery.

There is nothing that could cause a charge. There is no solar connected currently, the engine was off and we were not hooked up.

Mysterious.

The NE237 does manage both the cab and leisure battery, possibly allowing a current through from the cab battery acting as a B2B?

Wouldn't have thought so, but cant think of anything else.

Well something was charging it. I would guess the cab battery through a split charge relay that decided to activate for some reason. Voltage based ones could spuriously activate if the cab battery had a good charge and, perhaps, it got a bit warmer, pushing the voltage over a threshold.

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[BigDean]

Well something was charging it. I would guess the cab battery through a split charge relay that decided to activate for some reason. Voltage based ones could spuriously activate if the cab battery had a good charge and, perhaps, it got a bit warmer, pushing the voltage over a threshold.

Which is why I would love to disable all power management from the NE237 and have my own fully monitored Victron system. But I don't think it is possible without a complete rewire.

I guess I will just have to monitor it and try and understand its foibles.

 

[donkey]

Shoot me down if I am talking bo**cks, but have I not read somewhere about the Lithium BMS being responsible for the charging. I got the impression you could throw just about anything at them and the BMS would sort it out.

I guess from all the lithium charging questions, this is not the case.

Geoff

 

[Pausim]

Shoot me down if I am talking bo**cks, but have I not read somewhere about the Lithium BMS being responsible for the charging. I got the impression you could throw just about anything at them and the BMS would sort it out.

I guess from all the lithium charging questions, this is not the case.

Geoff

The BMS may prevent damage from things like over voltage but it does not control charging, this is done by the external devices. All the BMS does is shut the battery down if it senses a problem. Not all BMSs are the same.

 

[Pausim]

but the after driving to a park-up yesterday, about an hour away, the battery was only showing 13.3v.

I have more than once queried why people worry so much about the the mains charging of Li batteries. As long as the voltages are within the parameters specified by the manufacturer it is not going to cause any serious harm and when you are on an EHU you don’t need to worry about having a full battery. What does matter is having a full battery when you arrive at a location where there is no EHU. If the resting voltage dropped between setting off and then driving for an hour then there might be a problem but it sounds like the 13.8V was not a resting voltage but a mains charger maintenance level one.

 

[BigDean]

I have more than once queried why people worry so much about the the mains charging of Li batteries. As long as the voltages are within the parameters specified by the manufacturer it is not going to cause any serious harm and when you are on an EHU you don’t need to worry about having a full battery. What does matter is having a full battery when you arrive at a location where there is no EHU. If the resting voltage dropped between setting off and then driving for an hour then there might be a problem but it sounds like the 13.8V was not a resting voltage but a mains charger maintenance level one.

Good point. Just taken off EHU at home at it’s at 13.77v. So that should be okay…..

Unfortunately not going to be using her for a few weeks due to other commitments so will do more diagnostics when we next get out.

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[Hoovie]

I thought that voltage wasn't a good measure for Lithium batteries because the voltage-charge curve is so flat for most of the cycle?

What does the shunt say in terms of Ah?

Just for fun and to pretty well confirm your comment, here is a pretty typical charge cycle from a 100Ah Lithium battery. I took it from around 20% SoC (if I recall right) to the point it was full and so the current dropped to zero

voltage only really goes up noticably right at the end.

 

[BigDean]

Just for fun and to pretty well confirm your comment, here is a pretty typical charge cycle from a 100Ah Lithium battery. I took it from around 20% SoC (if I recall right) to the point it was full and so the current dropped to zero
View attachment 500769
voltage only really goes up noticably right at the end.

Thanks for that. I am pretty sure that’s what I will see if I did the same (which I will now do). The issue was once off charge it dropped then started to increase voltage even though there was no charge going in.
Thanks again.

 

[Hoovie]

Thanks for that. I am pretty sure that’s what I will see if I did the same (which I will now do). The issue was once off charge it dropped then started to increase voltage even though there was no charge going in.
Thanks again.

I think what you will see is typical and correct. Essentially the lower the current the greater the voltage will be and off-load it will be as high as the charger settings allow.
With your Shunt and the VRM, you should get a good idea what precisely is going on in terms of voltage and current levels (what time interval are you polling the system? the default is 15 minutes. I always change it to 1 minute as it gives a much better view)

It sounds like there is no way to turn off the Charger within the Nordelectronica? no dedicated breaker for it or even a protective fuse you could remove to stop it operating?
I know very little about the Nordelectronica, being much more familiar with the Sargent kit. I don't use the Split -Charge or the Mains Charging options in the Sargent as they are not very good basically and too low-powered, but at least with Sargent, it is much easier to not use them by the sound of it.

If you do find a way to disable the mains charger but want to be able to still charge the starter, you could get a trickle charger (the Votronics is not meant to be used with Lithium though) or you could get a multi output Victron charger such as an IP22 or IP43, which will charge two batteries relatively independantly. (The IP43 has a version that is designed to have a specific limited starter battery output as well as a primary Leisure Battery output and also can be connected to your Cerbo, which could be nice if you like keeping an eye on things)

 

[BigDean]

I think what you will see is typical and correct. Essentially the lower the current the greater the voltage will be and off-load it will be as high as the charger settings allow.
With your Shunt and the VRM, you should get a good idea what precisely is going on in terms of voltage and current levels (what time interval are you polling the system? the default is 15 minutes. I always change it to 1 minute as it gives a much better view)

It sounds like there is no way to turn off the Charger within the Nordelectronica? no dedicated breaker for it or even a protective fuse you could remove to stop it operating?
I know very little about the Nordelectronica, being much more familiar with the Sargent kit. I don't use the Split -Charge or the Mains Charging options in the Sargent as they are not very good basically and too low-powered, but at least with Sargent, it is much easier to not use them by the sound of it.

If you do find a way to disable the mains charger but want to be able to still charge the starter, you could get a trickle charger (the Votronics is not meant to be used with Lithium though) or you could get a multi output Victron charger such as an IP22 or IP43, which will charge two batteries relatively independantly. (The IP43 has a version that is designed to have a specific limited starter battery output as well as a primary Leisure Battery output and also can be connected to your Cerbo, which could be nice if you like keeping an eye on things)

Thanks for that. I have VRM set to 1min.

Will take another look at the NE237, but couldn't see anything obvious. Now weather is getting better, makes it far easier to look at these things with a clear mind and doors open!

If I can do it, I will probably go for an inverter/charger like the Multiplus. Dont need inverter, but it has VE.direct so I can monitor and control from VRM.

Thanks for your input.

 

[Hoovie]

Thanks for that. I have VRM set to 1min.

Will take another look at the NE237, but couldn't see anything obvious. Now weather is getting better, makes it far easier to look at these things with a clear mind and doors open!

If I can do it, I will probably go for an inverter/charger like the Multiplus. Dont need inverter, but it has VE.direct so I can monitor and control from VRM.

Thanks for your input.

Just to be picky ... it is not VW.direct, but VE.Bus on the Multiplus's. Doesn't make much difference to you as you have a Cerbo so can just plug in with a network cable, but just mentioning it for anyone running an RPi - they will need an MK3 adapter from Victron that is different to the VE.Direct to USB Dongles they would otherwise use.

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[BigDean]

Just to be picky ... it is not VW.direct, but VE.Bus on the Multiplus's. Doesn't make much difference to you as you have a Cerbo so can just plug in with a network cable, but just mentioning it for anyone running an RPi - they will need an MK3 adapter from Victron that is different to the VE.Direct to USB Dongles they would otherwise use.

Good point. I was thinking of the IP43 that has Ve.direct but given that is about the same price as a multiplus, may as well have the inverter.

 

[Hoovie]

Good point. I was thinking of the IP43 that has Ve.direct but given that is about the same price as a multiplus, may as well have the inverter.

Yup, the IP43 looks very nice, but the price is a bit silly and I recommend to folk to do exactly what you are thinking as they get a lot more for a little extra money
BTW - You could also look at the plastic cased "New Multiplus" as well as the metal "Compact" models - they are around £100 cheaper and still have the connectivity to the Cerbo (They are different dimensions for each model though instead of Victron using a common case for a bunch of them, so may or may not fit your space).

 

[BDM]

Quote from their website, if usefull 'Apuljack Engineering Ltd. are able to modify the original internal charging module in Nord NE237 units to provide a fixed 14.6V (+/- 0.1V) output to correctly charge lithium batteries.'

 

[BigDean]

Quote from their website, if usefull 'Apuljack Engineering Ltd. are able to modify the original internal charging module in Nord NE237 units to provide a fixed 14.6V (+/- 0.1V) output to correctly charge lithium batteries.'

Thanks for that, but the battery I have is a “drop in” so works on the gel setting.
Thanks.

 

[Off da Grid]

If it’s like our charger it has a 3 pin like plug the same as a kettle plug, ours is under the drivers seat so had to grope for it. It was hard wired to the mains circuit.
I fitted another socket and put a new lead with a plug on it and just switch it off as needed.
Since fitting the solar panel it’s hardly ever needed.

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[BigDean]

If it’s like our charger it has a 3 pin like plug the same as a kettle plug, ours is under the drivers seat so had to grope for it. It was hard wired to the mains circuit.
I fitted another socket and put a new lead with a plug on it and just switch it off as needed.
Since fitting the solar panel it’s hardly ever needed.

The problem is that it runs the rest of the vans 12v electrics/tank sensors etc.

Doesn’t look like I can just disable the charger.

Ah well, will see how it charges the lithium.

 

[BigDean]

Just for fun and to pretty well confirm your comment, here is a pretty typical charge cycle from a 100Ah Lithium battery. I took it from around 20% SoC (if I recall right) to the point it was full and so the current dropped to zero
View attachment 500769
voltage only really goes up noticably right at the end.

Do you have a chart showing the discharge curve?

My charge curve looks fine (as per manf specs), up to 14.4v for bulk, then drops to 13.8v to maintain as it should. When I come off EHU, it then drops to 13.27v within a couple of hours, then discharges as expected. Is that drop to 13.27v normal? According to the chart I have, that is only 90% charged.

Thanks

 

[Pausim]

My Relion behaves very much the same as yours and has done so reliably for the last 3 years. The discharge curve starts at a lower voltage (13.4V) than the charge curve finishes (14.6V) i.e. a significant voltage drop is normal. For my battery the published charge and discharge curves are quite different, what happens on the way up is very different to what happens on the way down. Battery voltages can be misleading when it comes to judging state of charge, I don’t think you have anything to worry about.

 

[Hoovie]

Do you have a chart showing the discharge curve?

My charge curve looks fine (as per manf specs), up to 14.4v for bulk, then drops to 13.8v to maintain as it should. When I come off EHU, it then drops to 13.27v within a couple of hours, then discharges as expected. Is that drop to 13.27v normal? According to the chart I have, that is only 90% charged.

Thanks

13.27V sounds perfectly fine to me as a resting voltage for a full lithium battery.

Chart:
Same battery. It has an interesting little drop in voltage part way through the discharge, but I have seen that with 3 different examples of this battery model so it is normal for at least this battery.

Constant load of 3.4A

 

[BigDean]

QUOTE="BigDean, post: 4527866, member: 53093"]
Do you have a chart showing the discharge curve?

My charge curve looks fine (as per manf specs), up to 14.4v for bulk, then drops to 13.8v to maintain as it should. When I come off EHU, it then drops to 13.27v within a couple of hours, then discharges as expected. Is that drop to 13.27v normal? According to the chart I have, that is only 90% charged.

Thanks

13.27V sounds perfectly fine to me as a resting voltage for a full lithium battery.

Chart:
Same battery. It has an interesting little drop in voltage part way through the discharge, but I have seen that with 3 different examples of this battery model so it is normal for at least this battery.

Constant load of 3.4A

(I'll have to update post from my computer. Copy/paste not working here it seems)
[/QUOTE]

Looks all good then

Thanks for your input.

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