Unexpected voltage readings after fitting lithium .

[headlight]

Today I removed my 2 x 100AH lead acid leisure batteries and fitted 2 x 105AH Fogstar Drift lithiums.
The lithiums had been fully charged at home prior to fitting.
I have changed my Victron MPPT, Victron Smart Shunt and Sterling B2B settings/parameters to suit the lithiums.
Once fitted I checked the lithiums voltage with a multimeter, which showed 14.4v.
There was a bit of solar, 6 watt from my 2 x 100 watt panels, so I figured that was what was raing the battery voltage.
But my shunt app and MPPT app both showed battery voltage as 13.4v ?
I turned on my voltage meter, which is totally independent being wired direct to the batteries, and it also showed 13.4v.
I tried another multimeter on the batteries which showed the same as the first multimeter, 14.4v.
Both Victron apps, smart shunt and smart solar, still showed 13.4v.
Yet again I was unable to connect to the Fogstar app ( I have been unable to connect to the Fogstar app since getting the batteries) and this time I also couldn't connect to the Xiaoxiang app which previously had worked, so I couldn't see what the battery apps were saying.
Does this voltage discrepancy sound correct ?

 

[Vansflyer]

It sounds weird! To establish the voltage you will need to isolate the solar and any other power input, I doubt 6w will raise the voltage to 14.4v but it might. Where did you put the meter probes, directly to the batteries or another part of the circuit?
How are the batteries wired, any other b2b device or battery manager, charger fitted? Was the van on hook up? And finally did the multimeter get zeroed before checking, and how long since the batteries were charged, all obvious stuff but we need the whole picture.
The Victron stuff should be spot on accurate so I believe 13.4V is likely to be accurate.
Overkill is a good App for connection, did you manage to try the IOS device as planned over the weekend?

 

[jwells]

Welcome to the lithium system set up mine field! Worth the effort to set up correctly and understand, nearly got mine sorted!!

 

[headlight]

It sounds weird! To establish the voltage you will need to isolate the solar and any other power input, I doubt 6w will raise the voltage to 14.4v but it might. Where did you put the meter probes, directly to the batteries or another part of the circuit?
How are the batteries wired, any other b2b device or battery manager, charger fitted? Was the van on hook up? And finally did the multimeter get zeroed before checking, and how long since the batteries were charged, all obvious stuff but we need the whole picture.
The Victron stuff should be spot on accurate so I believe 13.4V is likely to be accurate.
Overkill is a good App for connection, did you manage to try the IOS device as planned over the weekend?

Meter probes on battery terminals.
Batteries wired in parallel.
No other B2B or battery manager.
Not on hookup.
Both multimeters calibrated.
Lithiums charged on Thursday and again yesterday, so off charge for 24 hours.
Didn't manage to try an IOS device as I had to go to the girlfriends for weekend as she had a list of DIY for me to do lol.
All Victron and Sterling B2B parameters set as per Vanbitz recommendations.

 

[Raul]

Can you explain a bit better? I dont understand nothing what you mean by multimeter, meter, on the battery terminals? Where else?
13.4v sounds realistic and true for a full battery at rest.
I dont get it where you got the 14.4v, maybe solar side?

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[Vansflyer]

Meter probes on battery terminals.
Batteries wired in parallel.
No other B2B or battery manager.
Not on hookup.
Both multimeters calibrated.
Lithiums charged on Thursday and again yesterday, so off charge for 24 hours.
Didn't manage to try an IOS device as I had to go to the girlfriends for weekend as she had a list of DIY for me to do lol.
All Victron and Sterling B2B parameters set as per Vanbitz recommendations.

Thanks for the info.
Maybe worth isolating the batteries from everything else and each other and measure again. Then reconnect and see what you get then and compare. Where is the shunt in the circuit?

 

[jwells]

Keep an eye on the other lithium threads running, lot of people trying to get an understanding! Bringing all the information together for your particular setup may take a while - they are just not "drop in" replacements! Patience, you'll get there - good luck!

 

[Lenny HB]

Is there anything turned on in the van or the house that may be causing interefance also do you have any high voltage power lines, cell masts close by.
I'm thinking something may be interfering with digital meters and possibly your Bluetooth.

I think it's worth checking the batteries with an analog meter.

 

[headlight]

Can you explain a bit better? I dont understand nothing what you mean by multimeter, meter, on the battery terminals? Where else?
13.4v sounds realistic and true for a full battery at rest.
I dont get it where you got the 14.4v, maybe solar side?

Digital multimeter (2 different ones) direct on battery terminals show 14.4v but Victron smart shunt app and smart solar app show 13.4v.

 

[Lenny HB]

Digital multimeter (2 different ones) direct on battery terminals show 14.4v but Victron smart shunt app and smart solar app show 13.4v.

Victron shunts are normally spot on.

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[Raul]

Digital multimeter (2 different ones) direct on battery terminals show 14.4v but Victron smart shunt app and smart solar app show 13.4v.

It can't physically be at 14.4v without a input from somewhere. Try same multimeter a little past the terminals, or as low as posibile downstream, and make sure the meter is set to DC.

 

[headlight]

Is there anything turned on in the van or the house that may be causing interefance also do you have any high voltage power lines, cell masts close by.
I'm thinking something may be interfering with digital meters and possibly your Bluetooth.

I think it's worth checking the batteries with an analog meter.

Motorhome is in a storage park (blue storage Cardiff).
The digital multimeters I used are a Fluke and a Uni-T.
I also have 2 more multimeter, another Fluke and a Vicci but they are also digital.
Prior to changing the batteries, so the lead acids were still in place, both victron apps, my independent volt meter and my Fluke multimeter all gave corresponding voltages when I checked prior to removing the lead acids so I doubt it is cell mast or power line problem.
Nothing turned on in the van.

 

[headlight]

Victron shunts are normally spot on.

Exactly, but like wise I know that my multimeters are spot on.

 

[headlight]

It can't physically be at 14.4v without a input from somewhere. Try same multimeter a little past the terminals, or as low as posibile downstream, and make sure the meter is set to DC.

I did say there was a little solar which made me think that the multimeter reading of 14.4v was correct.
However both Victron apps disagree showing 13.4v.
And I've always found the Victron apps to be spot on and exactly match my multimeter reading.

 

[headlight]

Thanks for the info.
Maybe worth isolating the batteries from everything else and each other and measure again. Then reconnect and see what you get then and compare. Where is the shunt in the circuit?

Shunt was fitted by Vanbitz so I would expect it has been fitted correctly.
I checked battery voltages of the lithiums before taking them from the house this morning and both batteries showed 13.4v.

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[headlight]

Keep an eye on the other lithium threads running, lot of people trying to get an understanding! Bringing all the information together for your particular setup may take a while - they are just not "drop in" replacements! Patience, you'll get there - good luck!

Not according to Fogstar who I rang this afternoon to confirm parameter settings with.
They informed me they are drop in and you don't need to alter any settings.
When I pressed them they gave me charge and float voltages which I pointed out were different to the ones in the booklet that came with the batteries, to which I was told it doesn't really matter as the BMS will sort it all out.
They also told me that the voltage discrepancy was down to the BMS 'learning my set up' and that after 5 or 6 charge/discharge cycles everything would be fine.
Does that sound correct ?

 

[headlight]

I'm going to go back to the van tomorrow with 2 different multimeters and see if I can see what's going on. I've checked the calibration on both.

 

[the1andonly]

I once had a situation where i put meter on car battery 17V??? what got a second meter 16.7V.
took both meters to work to calibration room. picked them were they ok "yes no problem since i put new batteries in them" it is not uncommon for failing batteries (in multimeter) to give wierd results.
disconnect at batery terminals and measure with no load then measure at MPPT terminals.

 

[Lenny HB]

picked them were they ok "yes no problem since i put new batteries in them" it is not uncommon for failing batteries (in multimeter) to give wierd results.

With low battery digital meters always read high.

 

[Two Owl Ones]

Today I removed my 2 x 100AH lead acid leisure batteries and fitted 2 x 105AH Fogstar Drift lithiums.
The lithiums had been fully charged at home prior to fitting.
I have changed my Victron MPPT, Victron Smart Shunt and Sterling B2B settings/parameters to suit the lithiums.
Once fitted I checked the lithiums voltage with a multimeter, which showed 14.4v.
There was a bit of solar, 6 watt from my 2 x 100 watt panels, so I figured that was what was raing the battery voltage.
But my shunt app and MPPT app both showed battery voltage as 13.4v ?
I turned on my voltage meter, which is totally independent being wired direct to the batteries, and it also showed 13.4v.
I tried another multimeter on the batteries which showed the same as the first multimeter, 14.4v.
Both Victron apps, smart shunt and smart solar, still showed 13.4v.
Yet again I was unable to connect to the Fogstar app ( I have been unable to connect to the Fogstar app since getting the batteries) and this time I also couldn't connect to the Xiaoxiang app which previously had worked, so I couldn't see what the battery apps were saying.
Does this voltage discrepancy sound correct ?

same here i fitted a fogstar 280ah lithium battery the app worked for a week or so then i could no longer connect to it , test at the battery shows 14.4v .. however the factory fitted kit that monitors hab and engine battery shows 13.4v must be the trickery fogstar use to confuse us

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[Delboyarapaho]

I had a similar problem with a voltage difference between the batteries app and the victron solar controller. The fitter had left about 10m of cable between where they located the charger and the batteries so the 1v voltage drop was down to this cable run. They moved the charger and the difference went away.

 

[Lenny HB]

I had a similar problem with a voltage difference between the batteries app and the victron solar controller. The fitter had left about 10m of cable between where they located the charger and the batteries so the 1v voltage drop was down to this cable run. They moved the charger and the difference went away.

If he had fitted the correct size cables the volt drop would have been minimal.

 

[headlight]

Update.
I returned to the motorhome this morning armed with my other 2 multimeters that live in the flat after checking their batteries and calibration.
I also took my tablet as I have been able to connect to the Xiaoxiang app with it previously.
I turned on my independently wired volt meter which showed 13.5v
Smart shunt showed 13.56v.
Smart solar showed 13.60v.
Vici multimeter showed 13.60v
Fluke multimeter showed 13.60v.
Both direct on the battery terminals.
I managed to connect my tablet to the Xiaoxiang app which showed battery 1 at 13.6v, 100% SOC, 105AH capacity and cell values of 3.389v to 3.395v so a 0.006v difference.
Battery 2 showed 13.6v, 100% SOC, 105AH capacity, and cell values of 3.395v to 3.397v so a 0.002v difference.
I then tested the battery voltage direct on the battery terminals with the 2 multimeters I used yesterday and got 14.94v and 14.93v.
Both of these multimeters have low battery voltage warnings but neither one was showing a warning.
I changed the batteries in both and got 13.60v battery terminal readings on both so although neither meter was displaying low battery voltage obviously they were low.
Those 2 meters one is kept in the motorhome and one in my works van so I don't know if the below freezing temps had affected their batteries but obviously yesterday's false readings were caused by low battery voltage of the multimeters I used.
In conclusion voltage discrepancy sorted.

 

[Ingwe]

This is consistent with Lenny HB post at #19.
Thanks for reporting back so thoroughly. Glad it’s sorted.

 

[Ditcha]

Update.
I returned to the motorhome this morning armed with my other 2 multimeters that live in the flat after checking their batteries and calibration.
I also took my tablet as I have been able to connect to the Xiaoxiang app with it previously.
I turned on my independently wired volt meter which showed 13.5v
Smart shunt showed 13.56v.
Smart solar showed 13.60v.
Vici multimeter showed 13.60v
Fluke multimeter showed 13.60v.
Both direct on the battery terminals.
I managed to connect my tablet to the Xiaoxiang app which showed battery 1 at 13.6v, 100% SOC, 105AH capacity and cell values of 3.389v to 3.395v so a 0.006v difference.
Battery 2 showed 13.6v, 100% SOC, 105AH capacity, and cell values of 3.395v to 3.397v so a 0.002v difference.
I then tested the battery voltage direct on the battery terminals with the 2 multimeters I used yesterday and got 14.94v and 14.93v.
Both of these multimeters have low battery voltage warnings but neither one was showing a warning.
I changed the batteries in both and got 13.60v battery terminal readings on both so although neither meter was displaying low battery voltage obviously they were low.
Those 2 meters one is kept in the motorhome and one in my works van so I don't know if the below freezing temps had affected their batteries but obviously yesterday's false readings were caused by low battery voltage of the multimeters I used.
In conclusion voltage discrepancy sorted.

Don't know if you have already done this but if you set up a ve smart network within victron connect app with your victron gear( using Bluetooth or ve ports) they will sync together and talk to each other so you won't get the voltage discrepancy from one unit to the other.

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[headlight]

This is consistent with Lenny HB post at #19.
Thanks for reporting back so thoroughly. Glad it’s sorted.

I was just surprised that neither the Fluke or Uni-T multimeters I used yesterday displayed low battery voltage warnings as they are supposed to.

 

[Ingwe]

I was just surprised that neither the Fluke or Uni-T multimeters I used yesterday displayed low battery voltage warnings as they are supposed to.

I’ll certainly bear your experience in mind as I’ve got two reasonable quality digital test meters. One I keep in the van the other at home. I also have a clamp meter in the van. The batteries will be quite old and like your meters they’re supposed to have low battery warnings.

 

[Lenny HB]

If the batteries were cold the voltage across them would be low, that's why I always have a backup analog meter in my toolbox in the van.

 

[Raul]

Don't know if you have already done this but if you set up a ve smart network within victron connect app with your victron gear( using Bluetooth or ve ports) they will sync together and talk to each other so you won't get the voltage discrepancy from one unit to the other.

Even without a GX? I may be wrong, but I was under impression that DVCC has to be active to benefit of the voltage sense read from the shunt, and then the charger compensates if there is a cable loss.

 

[Ditcha]

Even without a GX? I may be wrong, but I was under impression that DVCC has to be active to benefit of the voltage sense read from the shunt, and then the charger compensates if there is a cable loss.

Yes even without the GX you can set up the shunt to broadcast voltage and current to the network