A real conundrum for you experts

[Purrfecttune]

What are Offgrid Solutions saying as a matter of interest?

First step was to remove the MPPT from the V.E. Smart Network which I did last night, but it hasn’t made any difference

I started the MH for a couple of minutes today and both the Victron B2B app and the MPPT app showed charging in Bulk. Switched off and the Fogstar Battery app showed an increase from 61% to 63%.

Rechecked the MPPT and it had reverted back to Float.

 

[headlight]

Today’s readings at 10.45am. It’s been a sunny morning.
The MPPT shows less and less charge per day, suggesting that as the motorhome is parked on the drive/not being used, the battery doesn’t need any more. (Yesterday’s shows slightly higher because I switched a new hairdryer on and off briefly).
The battery % is the same as yesterday with the draw showing 0.0a, now that I have switched the inverter off.
So it all suggests that the Fogstar battery app is not giving me a true reading and possibly needs a reset?
See pictures below, and thanks everyone for your input.
View attachment 959844View attachment 959845View attachment 959846View attachment 959847

You are on one cycle. For some reason the Fogstar app can be way off until you put some cycles on the battery.
Mine was way off until I reached 5-6 cycles then it settled down and since has been pretty close to my Victron Smart Shunt readings.
Also the app can't detect draws under 1amp such as your 0.8amp per hour from your inverter on standby.
Actually in my case it doesn't detect anything under 1.5 amps.
I wouldn't take any notice of the Fogstar app until you've put some cycles on the battery.
I would fit a shunt as it will detect 0.1amp.

 

[Purrfecttune]

You are on one cycle. For some reason the Fogstar app can be way off until you put some cycles on the battery.
Mine was way off until I reached 5-6 cycles then it settled down and since has been pretty close to my Victron Smart Shunt readings.
Also the app can't detect draws under 1amp such as your 0.8amp per hour from your inverter on standby.
Actually in my case it doesn't detect anything under 1.5 amps.
I wouldn't take any notice of the Fogstar app until you've put some cycles on the battery.
I would fit a shunt as it will detect 0.1amp.

Headlight:
Thank you sooo much. Advice from experience cannot be beaten.

As I surmised above, everything seems to add up except for the Fogstar Battery capacity reading as shown on the app.

I will use the inverter today and then hook up to EHU to recharge and see what occurs.

 

[Jabstatt]

I might be tempted to give it a right thrashing, using the electric water heating option.
Really exercise the system.
I did that regularly on my boat, two kW.
Really helped prolong the lead acids when they had largely been sitting on float for a month.

Tony

 

[MichaelT]

You really need to get it to 100% by EHU or Solar then you can reset your shunt and monitor. As above needs a few cycles to get it to reset.

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[ChrisL]

Does your onboard charger have a lithium setting, if not get a lithium compatible charger, disconnect the battery and charge it from that until the charger stops charging, then reconnect the battery and see what the app says, it does take a few cycles to stabilise. Also your tail current looks a bit high to me, this is used in conjunction with the absorbition voltage for the controller to decide when to go to float try changing it to 5 amps.

 

[Wanders from Glos]

So to be clear in my simple mind, you believe what the shunt says the % is not the Forster app?

 

[Wanders from Glos]

First step was to remove the MPPT from the V.E. Smart Network which I did last night, but it hasn’t made any difference

I started the MH for a couple of minutes today and both the Victron B2B app and the MPPT app showed charging in Bulk. Switched off and the Fogstar Battery app showed an increase from 61% to 63%.

Rechecked the MPPT and it had reverted back to Float.

Did they explain how to do all this when you collected it from them, you seem very proficient.

 

[headlight]

So to be clear in my simple mind, you believe what the shunt says the % is not the Forster app?

Yes.
My Fogstar app was up to 20% SOC out compared to my shunt SOC for the first 5-6 cycles.
After those first 5-6 cycles the Fogstar app settled down and since has been within 1-2% of what my shunt says.

 

[Purrfecttune]

Update:

Boiled a

Did they explain how to do all this when you collected it from them, you seem very proficient.

I am one of those people that likes to know what every thing does so research on the internet what all the functions do and then try them out (ensuring first that I can backtrack easily if necessary).

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[Purrfecttune]

OPS have suggested that I up the absorption time from the standard 2 hours to 6 hours.
So I have done this and reverted the tail current back to zero.

 

[headlight]

OPS have suggested that I up the absorption time from the standard 2 hours to 6 hours.
So I have done this and reverted the tail current back to zero.

I will be at my motorhome tomorrow, If you want I'll screenshot my settings for you.
They were given to me by Vanbitz so I'm sure that they are correct.
Other than the Fogstar app being flakey for the first 5-6 cycles my 230Ah Fogstar has performed perfectly for the 8-9 months I've had it.

 

[Purrfecttune]

Still learning and researching and have FINALLY found this page on Fogstar Batteries that not only explains it clearly, but confirms what some of the previous Funsters have already said above

www.fogstar.co.uk/blogs/fogstar-blog/deep-dive-demystifying-the-fogstar-drift-battery-management-system?srsltid=AfmBOorCQVmz4PAueEc4rLKIdWTUOXSmovJBFUmBV8vGYcbZSvHeBL-7

 

[Purrfecttune]

I will be at my motorhome tomorrow, If you want I'll screenshot my settings for you.
They were given to me by Vanbitz so I'm sure that they are correct.
Other than the Fogstar app being flakey for the first 5-6 cycles my 230Ah Fogstar has performed perfectly for the 8-9 months I've had it.

Hi Headlight. ‘Other than the Fogstar app being flakey for the first 5-6 cycles’ sums it up perfectly (see the link on my previous post).

 

[Purrfecttune]

Final comment (unless there are further developments).

Regarding the inverter which is a Victron 12/1200, I have now tested the following:
Electric kettle rated at 915w-1080w (drew 1250w/96a according to the app)
Toaster rated at 700w-850w (drew 900w/69a according to the app)
Microwave rated at ?? (drew 1600w/125a according to the app but initially/briefly kicked in much higher)
Two e-bikes combined (Trek & Ribble) total of 16a
Hairdryer rated at 1000w (drew 1140w/87a) NB this was on full power. The lower setting will trip out the inverter as explained in my separate posting.

Boiled a full kettle (7 minutes) but only switched everything else on briefly to check if it was okay with the inverter, so prolonged use hasn’t been tested.

I hope these figures are useful to those considering what size inverter to purchase

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[Purrfecttune]

FURTHER DEVELOPMENTS

Having monitored the system for more than a week I finally have the definitive answer.

The Solar is working marvellously BUT it is only keeping the Vehicle battery fully charged, as indicated by the Sargent Controller. It is not switching between the two.

The Leisure battery is clearly diminishing daily. The Sargent controller picture showing SOC for both batteries tallies with the Solar charge readings on the app picture.

The Sargent Controller power settings can be switched between Leisure and Vehicle batteries (I have it switched permanently to Leisure as in the picture) but this is only pertinent when on EHU.

So the answer is to ‘Hardwire’ the MPPT to the Leisure battery, bypassing the Sargent system.

I trust that this will be extremely helpful to some of those Funsters who have a similar system or are looking at a similar upgrade.

Finally yaaaahhhoooooooooooooo
(The mystery is no longer driving me nuts)

 

[Purrfecttune]

Bump

 

[barryd]

So have you rewired the system yourself? Have Off Grid Solutions been involved? I have to say this is a bit worrying "if" its been installed incorrectly.

 

[AdrianChen]

Bump

So yes I can see that the Solar output is at 13.5v, which I presume is what it is set to.

Can you follow the Solar output cables to see where they are connected, ie direct to a battery, or to some terminals on the the Sargent box?

I can see the panel is showing a 1amp solar input, so I guess it is correctly connected, but given the panel is showing the charge selector as leisure battery, and the "sun" symbol is shown under the Vehicle battery I'm not sure if the selection is working.

When the panel and PSU are turned off and back on again does the display change?


Sorry not much help I'm afraid I'm not familiar with Sargent.....

But at least it's bumped again

 

[Purrfecttune]

So have you rewired the system yourself? Have Off Grid Solutions been involved? I have to say this is a bit worrying "if" its been installed incorrectly.

Offgrid Power solutions have been brilliant, in daily communication with me sending daily screenshots to clearly identify what’s happening and have now booked me in for this Thursday to hardwire the solar to the leisure battery bypassing the Sargent system.

I am fully confident that they wired it in correctly (via the Sargent originally) but there is obviously an anomaly with the Sargent itself. The original mppt was replaced at the same time with a more efficient Victron to handle both the original and new solar panels.

However, before that, I had noticed from monitoring the Sargent Controller that it seemed to prioritise solar charging the vehicle battery over the leisure battery more and more as time went on, even if the leisure battery seemed a little low at times. So I am not confident that my solar was switching between the two efficiently prior to the upgrade anyway, so this could be related to that.

With the new system, the charging readings on the Sargent Controller for both EHU and Solar will now be redundant anyway, as I now have both the Fogstar and Victron apps which are more precise and linked by Bluetooth to my iPad.

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[AdrianChen]

Offgrid Power solutions have been brilliant, in daily communication with me sending daily screenshots to clearly identify what’s happening and have now booked me in for this Thursday to hardwire the solar to the leisure battery bypassing the Sargent system.

I am fully confident that they wired it in correctly (via the Sargent originally) but there is obviously an anomaly with the Sargent itself. The original mppt was replaced at the same time with a more efficient Victron to handle both the original and new solar panels.

However, before that, I had noticed from monitoring the Sargent Controller that it seemed to prioritise solar charging the vehicle battery over the leisure battery more and more as time went on, even if the leisure battery seemed a little low at times. So I am not confident that my solar was switching between the two efficiently prior to the upgrade anyway, so this could be related to that.

With the new system, the charging readings on the Sargent Controller for both EHU and Solar will now be redundant anyway, as I now have both the Fogstar and Victron apps which are more precise and linked by Bluetooth to my iPad.

Are they suggesting that you fit a Battery Master to maintain the starter battery independently of the Sargent? Think I would given what the system is doing.....

 

[barryd]

Offgrid Power solutions have been brilliant, in daily communication with me sending daily screenshots to clearly identify what’s happening and have now booked me in for this Thursday to hardwire the solar to the leisure battery bypassing the Sargent system.

I am fully confident that they wired it in correctly (via the Sargent originally) but there is obviously an anomaly with the Sargent itself. The original mppt was replaced at the same time with a more efficient Victron to handle both the original and new solar panels.

However, before that, I had noticed from monitoring the Sargent Controller that it seemed to prioritise solar charging the vehicle battery over the leisure battery more and more as time went on, even if the leisure battery seemed a little low at times. So I am not confident that my solar was switching between the two efficiently prior to the upgrade anyway, so this could be related to that.

With the new system, the charging readings on the Sargent Controller for both EHU and Solar will now be redundant anyway, as I now have both the Fogstar and Victron apps which are more precise and linked by Bluetooth to my iPad.

Your setup and what you had installed sounds very similar to mine so maybe when / if they do mine it should be wired directly also. If you don't mind I might mention your problems to them when discussing it at a later date. What I dont want to find is I drive 230 miles to get the install and then get home and find it needs to go back. I need it as simple as possible.

 

[Purrfecttune]

Are they suggesting that you fit a Battery Master to maintain the starter battery independently of the Sargent? Think I would given what the system is doing.....

They recommended a Battery Master at initial upgrade, which I had fitted.

 

[Purrfecttune]

Your setup and what you had installed sounds very similar to mine so maybe when / if they do mine it should be wired directly also. If you don't mind I might mention your problems to them when discussing it at a later date. What I dont want to find is I drive 230 miles to get the install and then get home and find it needs to go back. I need it as simple as possible.

Hi Barry
I truly believe that my issue was caused by a fault in the Sargent that had been slowly developing over the past couple of months, so might not be relevant to other systems.

Offgrid Power Solutions are excellent, they have been doing upgrades and conversions for many years and I have every confidence in them. They are the type of people who go the extra mile and can’t do enough for their customers

Rest assured, you will be very happy with their work

 

[Wanders from Glos]

Offgrid Power solutions have been brilliant, in daily communication with me sending daily screenshots to clearly identify what’s happening and have now booked me in for this Thursday to hardwire the solar to the leisure battery bypassing the Sargent system.

I am fully confident that they wired it in correctly (via the Sargent originally) but there is obviously an anomaly with the Sargent itself. The original mppt was replaced at the same time with a more efficient Victron to handle both the original and new solar panels.

However, before that, I had noticed from monitoring the Sargent Controller that it seemed to prioritise solar charging the vehicle battery over the leisure battery more and more as time went on, even if the leisure battery seemed a little low at times. So I am not confident that my solar was switching between the two efficiently prior to the upgrade anyway, so this could be related to that.

With the new system, the charging readings on the Sargent Controller for both EHU and Solar will now be redundant anyway, as I now have both the Fogstar and Victron apps which are more precise and linked by Bluetooth to my iPad.

We will be at Offgrid on Thursday as well, having a lithium system installed. Glad you have been impressed by them it’s always a bit of a nervous time allowing someone to tamper with your van.

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[barryd]

Hi Barry
I truly believe that my issue was caused by a fault in the Sargent that had been slowly developing over the past couple of months, so might not be relevant to other systems.

Offgrid Power Solutions are excellent, they have been doing upgrades and conversions for many years and I have every confidence in them. They are the type of people who go the extra mile and can’t do enough for their customers

Rest assured, you will be very happy with their work

Thanks. I also have a Sargent system and the proposed set up is very similar to yours. I have noticed ours when on hookup often decides to switch to the vehicle battery itself. Our current panel and controller is independent of the Sargent system and charges both the hab and cab battery. I don't really see an immediate advantage of going through the Sargent system anyway. I do want to investigate mine anyway as I think there is a 0.7amp draw on it with nothing supposedly switched on or drawing power.