Victron Cerbo GX (RPi) HELP...

[CueBall]

I guess when you changed the profile, it restarted a new cycle so all well

That would be my assumption as well - Although I could have unplugged the EHU for a couple of mins and then plugged it back in again which should, apparently, start a new cycle as well.

Also, in case it's of interest, when I went into the MPPT via BT to change the charge settings to match the IP22's stock Lithium profile, it had already been done... Can only assume that is something in the smart network.

 

[AdrianChen]

Based on setting the float to 13.5v (where Eco-Worthy suggest 100% SOC is 13.46v) what would be the harm in resetting the shunt to 100% SOC when it goes into float mode and holds the voltage at 13.5v? Whereas people suggest re-setting the SOC at the higher Absorption voltage which would result in a drop in SOC % as soon as the charger drops down into float (or storage, when you have float turned off).



No, as the Victron 20A IP22 isn't seen by the Pi as it doesn't have VE direct. Should I still do that if that were the case and given the GX can see the B2B and the MPPT (or at least it will see the MPPT once I sort a cable).

Will likely figure out how to prioritise solar once I get the MPPT into the GX, as it's plugged into my house when we aren't using it, so best to take advantage of the sun rather than the price of electricity lol.

Yes you could set to 100% when it drops to float, but doing it when the charger hits 0.2v under your absorb setting is good - Either way the shunt wont reduce the SOC as the voltage falls back, it will only reduce when the shunt detects a net outgoing current, the only time the shunt uses voltage is to determine when the battery is full which it cross-checks by using the tail current, the rest of the time it counts amps in and out and calculates the SOC from that.

I doubt the combined output of the b2b and solar will be close to your batteries max, so I wouldn't worry about the max charge current if you havent set one - wait untill you're happy that the basics are working as expected, then like me you'll be able to cock it up again by playing!

 

[CueBall]

So, I can now see the charger is reducing the voltage as it winds down in absorb mode before going into whatever mode it does in the stock Lithium profile (probably storage). Except, because I re-set the SOC to 100% when it hit absorb mode, the SOC is now falling (as there is a small load on the shunt from the RPi and 12v router). Currently SOC at 99.3% and flicking between idle & discharging.

Oddly I can't actually recall seeing a positive current figure through the shunt when the IP22 was charging, only when I was off grid and the MPPT was recharging the battery (that could be me imagining things though).

 

[Raul]

when it hit absorb mode, the SOC is now falling (as there is a small load on the shunt from the RPi and 12v router). Currently SOC at 99.3% and flicking between idle & discharging.

That is normal, mine does the same, from absorb voltage, down to the float voltage, the loads bleed about 0.4-0.6% SOC until reaches 13.5v and stabilises. Then a small amount starts to go into battery, to keep the 13.5v. After few hrs of absorb, that 0.4-0.6 can be filled back up, if enough float is held.
I don't bother about it, as long as it reached 100% on absorb, for me that's all it matters.

 

[CueBall]

I'm thinking I should just leave it be now and stop worrying about it lol...

There's plenty of capacity for the days we go off-grid per year (plus a huge solar panel). So I think I'm worrying over something that's not overly important.

Was just odd that things changed when I plugged in VE direct to GX (Pi). Albeit the Pi and 12V to USB for the Pi's power put a load on the battery which caused it to discharge down to the float voltage where it then stayed. Previously there wasn't any load on the battery when sat parked outside the house.

We're away this B/H weekend (on EHU) so will kick the guts out of the battery one night and see what the charger does.

Mrs CueBall will likely wonder why I spend so much time staring at a tiny touch screen on the wall rather than beer & BBQ (likely in the rain - GRRR), but there we go haha.

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[Lenny HB]

Also, in case it's of interest, when I went into the MPPT via BT to change the charge settings to match the IP22's stock Lithium profile, it had already been done... Can only assume that is something in the smart network.

Can't happen with a Pi as you are only monitoring each device.

 

[CueBall]

Can't happen with a Pi as you are only monitoring each device.

I was going through VE Connect at that time and everything is connected via their "smart network" - e.g. sync'd charging etc.

 

[Raul]

Was just odd that things changed when I plugged in VE direct to GX (Pi). Albeit the Pi and 12V to USB for the Pi's power put a load on the battery which caused it to discharge down to the float voltage where it then stayed. Previously there wasn't any load on the battery when sat parked outside the house.

The most important component in a GX venus system is a multiplus, VE direct or VE bus, connection. It even has a battery monitor, not as accurate as a shunt, but, in absence of a shunt this monitor is used by default.
Once you connect all your devices to the GX and BT networked the ones that support it, the info becomes more accurate. Even an idle consumption of a multiplus can be few Watts on AC, with no AC load, or, it will add up in DC loads.
There is ways round it for purists, you can set shunt 0 current calibration with the inverter on but no load, that will give you all the right figures on display, and all add up.
Downside the shunt will lie to you by few W.
What I do, when I power a shunt, with nothing connected, nothing in or out, I reset the shunt to 0 amps and leave it. That way, anything connected after, it will register as a load or charge, depending what it is.
I think you will find out in time the quirks, most are very simple and we overthink it.
Give a little time get used to the system and slowly things will fall into place.

 

[Lenny HB]

I was going through VE Connect at that time and everything is connected via their "smart network" - e.g. sync'd charging etc.

I didn't think you could do that without a genuine Cerbo GX, Raul will know.

 

[Raul]

I dodn't think you could do that without a genuine Cerbo GX, Raul will know.

Honestly, I don't know Lenny HB, I have two chargers in the system and both networked. If I adjust one, I have to do the other as well manually, it doesn't mirror the settings by itself.
Maybe is a new feature I haven't come across it yet, or something else.

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[AdrianChen]

Honestly, I don't know Lenny HB, I have two chargers in the system and both networked. If I adjust one, I have to do the other as well manually, it doesn't mirror the settings by itself.
Maybe is a new feature I haven't come across it yet, or something else.

Yes I didn't think the set values would alter - and thought the syncing just kept the Bulk-Abs-Float stages in line. Haven't seen any new feature personally, but don't read everything they do. On the latest Beta firmware though....

 

[CueBall]

The most important component in a GX venus system is a multiplus

Thinking back I should have gone for the 12/1200 Multiplus, but at the time I got a good deal on a 20A IP22 & 12/1200 Inverter, saving over £100 on the Multiplus price.

The downside now is that I can't see incoming AC, as the IP22 doesn't have VE Direct (though am assuming the Multiplus meters incoming AC to its charger).

What I do, when I power a shunt, with nothing connected, nothing in or out, I reset the shunt to 0 amps and leave it. That way, anything connected after, it will register as a load or charge, depending what it is.

I should really do that, but that would involve either unbolting everything from bus bars or disconnecting the negative from the bus bar to the shunt. Just turning everything off might not give me a zero current figure, as, for example, the Battery Master can't be turned off.

I think you will find out in time the quirks, most are very simple and we overthink it.

I hear you there, I'm still trying to figure out how to get the system to prioritise solar charging (or holding float) over the IP22 when plugged in to EHU - If such a setting even exists.

I didn't think you could do that without a genuine Cerbo GX

It's feasible the settings were already the same, but can't be sure. I know the chargers mirror each other as they are smart networked, so don't fight against each other, doing different things.

 

[Raul]

I hear you there, I'm still trying to figure out how to get the system to prioritise solar charging (or holding float) over the IP22 when plugged in to EHU - If such a setting even exists.

I think that option needs a multiplus with a CT current sensor. It is in the GX settings menu in somewhere. Multiplus 2 has this feature and takes a CT clamp.

 

[Raul]

Thinking back I should have gone for the 12/1200 Multiplus,

I may be upgrading mine sooner that I tought, and will be selling the multiplus 12/2000/80 in here.

 

[wireman]

Sorry to highjack this thread, but seeing as though we have lots of knowledgeable peeps here, I will ask just one simple question: If I want to put a shunt on my Burstner, I read that there should only be one negative cable on the shunt to the battery. On my battery, there are two black wires, and I have no idea where that comes from, and it's not easy to trace as my disability makes it very difficult to get into odd places. So the question is If I put a shunt on, will it work ok with the very small diameter wire? This has been so since purchase. I guess I could borrow a clucker (Ex Network with CAT5, etc and fibre installer) and disconnect the earth and find its use that way... I just had a thought... I suppose I could put that earth onto the back end of the shunt and just run a single cable to the shunt... (Daft twont incorporated called wireman)

Thanks for listening to an old codger.

Tony

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[AdrianChen]

I think that option needs a multiplus with a CT current sensor. It is in the GX settings menu in somewhere. Multiplus 2 has this feature and takes a CT clamp.

On the MultiPlus II there is a setting to do this but not sure if it would apply to the IP22:

 

[autorouter]

Sorry to highjack this thread, but seeing as though we have lots of knowledgeable peeps here, I will ask just one simple question: If I want to put a shunt on my Burstner, I read that there should only be one negative cable on the shunt to the battery. On my battery, there are two black wires, and I have no idea where that comes from, and it's not easy to trace as my disability makes it very difficult to get into odd places. So the question is If I put a shunt on, will it work ok with the very small diameter wire?

The shunt is basically a block of solid metal, with a bit of electronics attached to measure the amps passing through it. Remove the two wires from the battery negative terminal, and connect them to the 'Load' side of the shunt. Then get a new piece of wire to connect the 'Battery' side of the shunt to the battery negative terminal.

The only difficulty might be that the existing wires might need new ends crimping onto them, that are big enough for the shunt connections. I think they are M10 size, which is on the large side for battery crimp connections.

 

[Raul]

On the MultiPlus II there is a setting to do this but not sure if it would apply to the IP22:

View attachment 1060407

That's the one, when that is active, I remember some more settings in the system menu. Never needed that so I took no interest. Alternatively, you can set assistant to ignore AC under certain conditions. One of those conditions can be SOC or peak power and more.

 

[Hoovie]

On the MultiPlus II there is a setting to do this but not sure if it would apply to the IP22:

View attachment 1060407

What I do to prioritise Solar over EHU is quite simple .... Just set the charge voltages on the Mains Charger a little lower than than the Solar Controller.
Then when the solar controller is doing its thing, the mains charger sees a voltage higher than its setting and thinks it has nothing to do. No need to have connected devices for that to work either (although I do, but that is simply not a factor).

 

[AdrianChen]

What I do to prioritise Solar over EHU is quite simple .... Just set the charge voltages on the Mains Charger a little lower than than the Solar Controller.
Then when the solar controller is doing its thing, the mains charger sees a voltage higher than its setting and thinks it has nothing to do. No need to have connected devices for that to work either (although I do, but that is simply not a factor).

So if the battery voltage is low, the Mains Charger still sees the solar controllers output voltage? - I don't use the Victron facility having tried it, so just leave EHU off when I don't need it - but all for something automatic.........

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[Hoovie]

So if the battery voltage is low, the Mains Charger still sees the solar controllers output voltage?

The output of the mains charger, the output of the solar controller and the battery are obviously all connected together and are the same (ignoring cable losses), so if that voltage is below the charging voltage set on the mains charger, the mains charger will operate same as the solar controller will output, so both will be charging the battery.
The point is that once the battery is in a full or nearly full state (depending on how you set things up) and the voltage has increased to the set threshold parameter, the solar controller will be the device that maintains the battery, not the mains charger.

Both still do charging, but my reply (and how I use this config myself) was in response to the question of "I'm still trying to figure out how to get the system to prioritise solar charging ([f]or holding float) over the IP22 when plugged in to EHU"

- I don't use the Victron facility having tried it, so just leave EHU off when I don't need it - but all for something automatic.........

 

[AdrianChen]

The output of the mains charger, the output of the solar controller and the battery are obviously all connected together and are the same (ignoring cable losses), so if that voltage is below the charging voltage set on the mains charger, the mains charger will operate same as the solar controller will output, so both will be charging the battery.
The point is that once the battery is in a full or nearly full state (depending on how you set things up) and the voltage has increased to the set threshold parameter, the solar controller will be the device that maintains the battery, not the mains charger.

Both still do charging, but my reply (and how I use this config myself) was in response to the question of "I'm still trying to figure out how to get the system to prioritise solar charging ([f]or holding float) over the IP22 when plugged in to EHU"

The output of the mains charger, the output of the solar controller and the battery are obviously all connected together and are the same (ignoring cable losses), so if that voltage is below the charging voltage set on the mains charger, the mains charger will operate same as the solar controller will output, so both will be charging the battery.
The point is that once the battery is in a full or nearly full state (depending on how you set things up) and the voltage has increased to the set threshold parameter, the solar controller will be the device that maintains the battery, not the mains charger.

Both still do charging, but my reply (and how I use this config myself) was in response to the question of "I'm still trying to figure out how to get the system to prioritise solar charging ([f]or holding float) over the IP22 when plugged in to EHU"

Yes I get that - Thanks for the explanation.

 

[wireman]

The shunt is basically a block of solid metal, with a bit of electronics attached to measure the amps passing through it. Remove the two wires from the battery negative terminal, and connect them to the 'Load' side of the shunt. Then get a new piece of wire to connect the 'Battery' side of the shunt to the battery negative terminal.

The only difficulty might be that the existing wires might need new ends crimping onto them, that are big enough for the shunt connections. I think they are M10 size, which is on the large side for battery crimp connections.

Cheers, mate; much appreciated. OK, and I could cut as near to the shunt as possible and crimp on two ends that are connected together on the load side. Then, just crimp on a separate connector for the battery side, utilising the end piece, or do you think that the existing wire is not good enough to run both earth terminals? The small wiring is not very thick, but I could measure it for you if you would be so kind as to give me some insight on what capacity it is being utilised for and what thickness of wire would be needed if I have to replace it. Unfortunately, it runs into a mass of wires and I can't get any further into where it goes.

Kindest Regards

Tony

 

[autorouter]

I could cut as near to the shunt as possible and crimp on two ends that are connected together on the load side. Then, just crimp on a separate connector for the battery side, utilising the end piece, or do you think that the existing wire is not good enough to run both earth terminals?

I would think just a piece of the thicker of the two wires would be OK. It would only be a very short length, so the extra voltage drop would be negligible.

You could even crimp the thicker and thinner wires together on the battery side - what matters is the total copper area. Or if you come across some some more substantial cable, you could use that. No problem electrically with it being too thick, it's just extra weight and cost.

 

[wireman]

I would think just a piece of the thicker of the two wires would be OK. It would only be a very short length, so the extra voltage drop would be negligible.

You could even crimp the thicker and thinner wires together on the battery side - what matters is the total copper area. Or if you come across some some more substantial cable, you could use that. No problem electrically with it being too thick, it's just extra weight and cost.

Cheers. Many thanks

Kind Regards
Tony

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[CueBall]

Spent the weekend away on EHU and think I have solved my issue.

I sync'd the battery SOC to 100% when the charger moved from Bulk into absorption, except it then slowly moved down to around 81% over the next two days (and then stayed there).

Read lots of posts and decided to change my charged voltage to 0.2v less than the float/storage voltage (previously it was set 0.2v less than my absorption voltage).

Re-sync'd the SOC when it went into absorption, after forcing the charger into another cycle.

SOC sat at 100% ever since (as the charger was holding the battery voltage at the float voltage which is the fully charged voltage).

Why I had it set at 0.2v below absorption voltage is unknown, as obviously the chargers will let the battery discharge from absorption, down to float, so the shunt saw that and reported the drop in SOC accordingly.

 

[Raul]

Read lots of posts and decided to change my charged voltage to 0.2v less than the float/storage

That is a setting for lead batteries, with this setting on lithium, the shunt will reset way prematurely,.

 

[Raul]

SOC sat at 100% ever since (as the charger was holding the battery voltage at the float voltage which is the fully charged voltage).

False 100% soc, lithium doesn't float, is full at or after absorb., then needs to come down a little to hold a float voltage for loads, you can even skip absorb all together by setting it very low, and cancel rebulk.

 

[CueBall]

False 100% soc, lithium doesn't float, is full at or after absorb., then needs to come down a little to hold a float voltage for loads, you can even skip absorb all together by setting it very low, and cancel rebulk.

I have float set to 13.65v, which the charger holds the voltage at when loads are applied (which is what I want), so would this not be 100% then? It seems, based on previous settings, it wanted to report that SOC as 81% (previous fully charged voltage was 14.1v).

Eco-worthy have this chart as their SOC on the 280aH battery.

 

[Lenny HB]

I think you would be better using what are more normal settings I would ignore those Evoworthy voltages as they are for a battery at rest.

I have Fogstar batteries my charger is set absorbtion 14.25v (14.2v to 14.3v should be fine) & float to 13.5v (you don't need the battery to take a charge unless there is a load on it) the charged voltage on my shunt is set to 14.1v, my SOC is always within 1%.

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