I need a battery expert

[wp1234]

Here is a mystery that perhaps a battery expert can help with , sorry it’s a long post.
In November 2021 I bought two 110Amh Victron Gel batteries, not cheap!
After a trip abroad in March 2022 one of the batteries failed ( low voltage)and was replaced under warranty with another Victron Gel battery.
I now have the same problem but this time with the two Victron batteries ( the replacement fitted 03/03/2022 and the original fitted 16/11/2021) .
I have a Victron shunt fitted to the battery set up and this shunt tells me what is going on with the batteries and I attach 4 pictures ( which shows the massive voltage drop on each battery after very little Amp hour drain and in a short space of time.The shunt readings are taken when batteries were not connected together to prove that both batteries have a fault.Also to note is that the vans own system also alarms on low voltage so it’s not a shunt only alarm.

I have checked everything that I can on the motorhome and can only conclude that if the charger is charging as it should ( which I think it is , it’s a CBE unit set on GEL ) and there’re is no parasitic drain ( which there isn’t) so the only conclusion I can come to is that for whatever reason the original battery supplied back in Nov 2021 may also have been faulty) and is somehow responsible for destroying the newer replacement battery.

Is there anything that anyone can think of that could cause three battery failures ? Thanks in advance

 

[PeterCarole29]

I,m no expert but it might help if you show you battery leads are linked and there size and how they are crimped there lenghts also

 

[Kannon Fodda]

Those screenshot shows over 5A being drawn from battery A. You have something creating a fair load on your system.

 

[wp1234]

Those screenshot shows over 5A being drawn from battery A. You have something creating a fair load on your system.

Sorry I should have said that the load is 5amp as the to and light we’re on . Usual draw when not using is around 0.2amps.The voltage drop happens suddenly basically whilst watching the TV

 

[wp1234]

I,m no expert but it might help if you show you battery leads are linked and there size and how they are crimped there lenghts also

Hi Peter , The cabling is bog standard battery cable(as fitted by Laika) as shown in the picture and here is the wiring diagram when both batteries are connected up . I’m just running with one battery at the moment .The cables between the two batteries are as short as they can be and same length .Might also help to show you the history of the voltage drop , the graph shoots back up when I put back on EHU.

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[Lenny HB]

Does look a bit odd the consumed ah compared to the percentage not too bad but the voltage is dropping off I think I would agree looks like duff batteries.
Is there a date on the batteries I'm wondering if they have been in stock for a long time without a charge.

I would measure the charging voltages in case there is a charger fault, the batteries should charge up to 14.4v then the absorption phase should hold at that voltage for a few hours before dropping to a float of 13.6 - 13.8v. Also check the batteries are not getting hot while charging.

Also a shot of your shunt settings would be useful.

 

[Bobby-gg]

Something in the back of my mind says that cbe chargers are marked incorrectly for the charging profiles.
You might want to goggle it for your own peace of mind

 

[Hoovie]

Sorry I should have said that the load is 5amp as the to and light we’re on . Usual draw when not using is around 0.2amps.The voltage drop happens suddenly basically whilst watching the TV

FWIW, When I get an extra 5A or so load on my system (happens every 90 minutes or so when the fridge kicks in), I get a voltage drop on my Lead Carbon batteries of around 0.1V. As I have a larger bank than you, your drop would be bigger but not dramatically so.
The difference in voltage between the two screenshots for battery A in the space of a minute is very high for no apparent change in load.
I can only see three reasons for this:
1) battery is failing - maybe a cell is going bad.
2) there is a load connected to the battery on the wrong side of the shunt (the BAT side, not the LOAD side), which would mean the Battery Monitor is not picking up the extra load
3) You have poor connections going to/from the shunt. If you have say a poor crimp on one of the cables that could cause the kind of reporting you are getting.

1) is a possibility, 2) I think you would have spotted and fixed as you sound like you know what you are doing, but 3) is not an obvious one to spot and is maybe more common than people imagine.
What you haven't done (as far as I can tell) is validate the voltage reported by the shunt with the voltage at the battery terminals as checked with a voltmeter? I think that is an essential check before going back to Victron to report a bad battery.

 

[wp1234]

Does look a bit odd the consumed ah compared to the percentage not too bad but the voltage is dropping off I think I would agree looks like duff batteries.
Is there a date on the batteries I'm wondering if they have been in stock for a long time without a charge.

I would measure the charging voltages in case there is a charger fault, the batteries should charge up to 14.4v then the absorption phase should hold at that voltage for a few hours before dropping to a float of 13.6 - 13.8v. Also check the batteries are not getting hot while charging.

Also a shot of your shunt settings would be useful.

Thanks for the feedback Lenny.I’m in Portugal at the moment so testing the batteries in detail is a little more difficult . I carry a car battery charger and I have used that on both batteries once the voltage dropped . The weird thing is that when the car battery charger is connected it shows battery is at 80% ish capacity …. So I’m thinking that the battery is in fact pretty full but just not providing the voltage required to run things. Also to support the shunt low voltage alarm the Laika system also shuts down the Motorhome on low voltage on the control display .
Shunt settings are attached , I only have one battery attached at the mo hence 110 a setting.

 

[wp1234]

FWIW, When I get an extra 5A or so load on my system (happens every 90 minutes or so when the fridge kicks in), I get a voltage drop on my Lead Carbon batteries of around 0.1V. As I have a larger bank than you, your drop would be bigger but not dramatically so.
The difference in voltage between the two screenshots for battery A in the space of a minute is very high for no apparent change in load.
I can only see three reasons for this:
1) battery is failing - maybe a cell is going bad.
2) there is a load connected to the battery on the wrong side of the shunt (the BAT side, not the LOAD side), which would mean the Battery Monitor is not picking up the extra load
3) You have poor connections going to/from the shunt. If you have say a poor crimp on one of the cables that could cause the kind of reporting you are getting.

1) is a possibility, 2) I think you would have spotted and fixed as you sound like you know what you are doing, but 3) is not an obvious one to spot and is maybe more common than people imagine.
What you haven't done (as far as I can tell) is validate the voltage reported by the shunt with the voltage at the battery terminals as checked with a voltmeter? I think that is an essential check before going back to Victron to report a bad battery.

Thank you for the feedback very useful.
Just taking aboard your thoughts the only thing connected to the shunt are as per picture ( sorry it’s a bit of a rough edit) .My battery cabling is as per diagram and I’m fairly sure it’s correct.
As regards voltage validation , I take your point and I will do this before pursuing a claim although the shunt voltage readings will I’m sure be correct since the vans system also automatically shuts down at 11.0 Volts regardless what the shunt reads .

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[wp1234]

Something in the back of my mind says that cbe chargers are marked incorrectly for the charging profiles.
You might want to goggle it for your own peace of mind

Will check this out cheers

 

[Lenny HB]

Shunt setting look OK.

 

[Hoovie]

Thank you for the feedback very useful.
Just taking aboard your thoughts the only thing connected to the shunt are as per picture ( sorry it’s a bit of a rough edit) .My battery cabling is as per diagram and I’m fairly sure it’s correct.

Take that BAT Minus cable and really check both ends ring terminals. pull them around etc just to make sure. The downside of heat shrink is it can hide problems.

As regards voltage validation , I take your point and I will do this before pursuing a claim although the shunt voltage readings will I’m sure be correct since the vans system also automatically shuts down at 11.0 Volts regardless what the shunt reads .

Remember the vans system is using the same -ve battery connections as the Shunt is so a -ve cable issue on the Shunt will also affect the way the van voltage reporting and low voltage shutdown go.
(the only way it would not be affected for sure is if the factory monitoring WAS bypassing the shunt, which of course you don't want!)
As far as wrong readings go, if there is a disparity between voltage at battery terminals and voltage from BOTH Shunt and Van systems, the only cable that should have that effect is the -ve cable from battery to Shunt BAT.
One other thing that can affect voltage reading is a rare one ... loose PCB screws on the shunt. But that would be a shunt-only issue.

 

[wp1234]

Take that BAT Minus cable and really check both ends ring terminals. pull them around etc just to make sure. The downside of heat shrink is it can hide problems.

Remember the vans system is using the same -ve battery connections as the Shunt is so a -ve cable issue on the Shunt will also affect the way the van voltage reporting and low voltage shutdown go.
(the only way it would not be affected for sure is if the factory monitoring WAS bypassing the shunt, which of course you don't want!)
As far as wrong readings go, if there is a disparity between voltage at battery terminals and voltage from BOTH Shunt and Van systems, the only cable that should have that effect is the -ve cable from battery to Shunt BAT.
One other thing that can affect voltage reading is a rare one ... loose PCB screws on the shunt. But that would be a shunt-only issue.

That’s a very good shout . I think I will take the shunt out of the system completely for now and take the battery connections back to factory fitted originals and see how that goes .Cheers

 

[68c]

When using the extra car battery charger are you connecting directly to the batteries as that will bipass your battery monitor so it will not know the true state of charge. You could use your car charger to fully charge the batteries then reset the monitor so it knows the batteries are actually at 100%.

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[wp1234]

When using the extra car battery charger are you connecting directly to the batteries as that will bipass your battery monitor so it will not know the true state of charge. You could use your car charger to fully charge the batteries then reset the monitor so it knows the batteries are actually at 100%.

Yes that’s what I’m doing thank you. Tonights experiment was to take everything back to factory settings - one battery , no shunt ….. and 2 hrs later I black out on low voltage ! Grrrr . So the only conclusion I can come up with is that for some reason the battery although full cannot supply the right voltage ….or am I missing something ??

 

[Raul]

The +ve feed to the shunt, carries no significant current, so it works as voltage sense to. That will give a accurate voltage reading, despite any load or charge. So measuring to the battery terminals with a meter it’s pointless. Unless the wiring is faulty. Those crimps look poor crimps. Reminds me of Halfords batttery cable flattened with pliers. A proper crimp will have a considerable smaller diameter on the lug, compared to the cable.
Even so, 3 batteries going south, it’s to much of a coincidence of being all faulty. I think something in your system is not set right, or a multitude of factors that contributes to this.
You will need A clamp meter to confirm the current going in or out of the batteries under same mutated tests. I’m not certain If your shunt is bypassed,

 

[wp1234]

The +ve feed to the shunt, carries no significant current, so it works as voltage sense to. That will give a accurate voltage reading, despite any load or charge. So measuring to the battery terminals with a meter it’s pointless. Unless the wiring is faulty. Those crimps look poor crimps. Reminds me of Halfords batttery cable flattened with pliers. A proper crimp will have a considerable smaller diameter on the lug, compared to the cable.
Even so, 3 batteries going south, it’s to much of a coincidence of being all faulty. I think something in your system is not set right, or a multitude of factors that contributes to this.
You will need A clamp meter to confirm the current going in or out of the batteries under same mutated tests. I’m not certain If your shunt is bypassed,

Thanks Raul , I agree seems odd that three batteries have failed but am struggling to find what else could cause it . My CBE charger is set to Gel charge and is charging , my Solar seems to be charging and there appears to be no parasitic drain on my system according to the shunt ? What do you mean my shunt is ‘bypassed’ ? Cheers

 

[Raul]

You could have a -ve draw of the chassis without going trough the shunt. You should have a -ve connection from load side of shunt to the chassis, and nothing on -ve post of the battery, only shunt with battery side to it. If you have a -ve from battery to chassis, this will bypass the shunt. Chassis -ve should go to the load side of the shunt. Make sure this is what you have.
With a clamp meter, measure the current going out of the battery, and compare it to the one displayed on shunt app. If meter reads higher current than the app, you have a path where it bypasses the shunt. You need to dig and find that path, and re direct it as explained above. I’m pretty sure you are competent and know what you are doing. Be methodical, and eliminate any possible fault on your system, then last resort, blame the batteries.
Maybe you could borrow a clamp meter near a funster. I could lend you mine, but I’m abroad for few weeks.

 

[flatpackchicken]

On looking at your connections, it looks to me as though you may have the wrong connections, I see the pic is only one battery connected at the moment but the red cable would not be long enough to connect to second battery as shown in my diagram !!!! If you have the first battery connected to the second battery and the connections going to mh come off the first battery then you are not getting the correct voltage coming from both batteries as you drag first battery down and the connection with second battery is only passing through current and you may not get the correct reading from your double batteries but only from the first battery that your drawing from !!!!!!!!! Hope I explained it properly!!!! Please see the diagram as I problems with my batteries when I first had my mh wired up wrong way and giving similar problems as you, but when I rewired the batteries as first diagram then hey Ho all presto all problems were resolved. I had 2 x 120A batteries and had to replace 1 as it kept going down but charged up ok and held charge when sitting !!!!!! Hope this helps

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[wp1234]

On looking at your connections, it looks to me as though you may have the wrong connections, I see the pic is only one battery connected at the moment but the red cable would not be long enough to connect to second battery as shown in my diagram !!!! If you have the first battery connected to the second battery and the connections going to mh come off the first battery then you are not getting the correct voltage coming from both batteries as you drag first battery down and the connection with second battery is only passing through current and you may not get the correct reading from your double batteries but only from the first battery that your drawing from !!!!!!!!! Hope I explained it properly!!!! Please see the diagram as I problems with my batteries when I first had my mh wired up wrong way and giving similar problems as you, but when I rewired the batteries as first diagram then hey Ho all presto all problems were resolved. I had 2 x 120A batteries and had to replace 1 as it kept going down but charged up ok and held charge when sitting !!!!!! Hope this helps View attachment 732040

Hi there , thanks for the info . I think I did have it wired it up correctly when I had two batteries connected but I might be wrong . I attach my wiring diagram .

 

[flatpackchicken]

Yes it does look like you have it wired up like I suggested . So sorry can’t help anymore but good luck in sorting it

 

[wp1234]

You could have a -ve draw of the chassis without going trough the shunt. You should have a -ve connection from load side of shunt to the chassis, and nothing on -ve post of the battery, only shunt with battery side to it. If you have a -ve from battery to chassis, this will bypass the shunt. Chassis -ve should go to the load side of the shunt. Make sure this is what you have.
With a clamp meter, measure the current going out of the battery, and compare it to the one displayed on shunt app. If meter reads higher current than the app, you have a path where it bypasses the shunt. You need to dig and find that path, and re direct it as explained above. I’m pretty sure you are competent and know what you are doing. Be methodical, and eliminate any possible fault on your system, then last resort, blame the batteries.
Maybe you could borrow a clamp meter near a funster. I could lend you mine, but I’m abroad for few weeks.

Thanks Raul . I hate things I don't understand so I’m ordering a clamp mete as you suggest , this one (UNI-T DIGITAL UT210E 100Amp 600V AC DC CLAMP METER Multimeter True RMS VFC diode) and will start using it in earnest as you suggested to fault find when I get home from Portugal next week …thank you for the advice to date and will be back when I have more data .