Alternator Charge Current AWOL

[bigtwin]

I recently (prior to setting off on our current winter trip) fitted a Victron Smartshunt and appear to have a problem whereby it doesn’t see any charge current from the alternator.

Setup:
Electroblok EBL99 and associated IT99-2 display/control unit. A pair of Sonnenschein 120Ah gel batteries and a single 120W solar panel fed through a PWM controller. The SmartShunt is connected as per the instructions (i.e. all charge/discharge sources pass through the shunt with the other side of the shunt connecting directly to the bank negative).

Symptoms:

When on EHU:
Both the IT99 and the shunt show the same charge current (all good).

When the engine is running:
the IT99 display shows a charge current of circa 15A but the shunt shows only a few amps, assumed to be from the solar. (this is anomalous).

Conclusion:

I’m presuming that the batteries are actually being charged (the IT99 shows a charge current) but I’m unsure about how the SmartShunt can appear not to see this charge current.

As yet (currently on the road) I haven’t undertaken any investigations to try to understand what’s happening.

I’d appreciate any thoughts that might help explain this apparent anomaly.

Ian

 

[Hoovie]

obvious question .... where did you fit the shunt? photos?

 

[Lenny HB]

Is the shunt fitted the correct way round?

 

[ChrisL]

Check the leads with a clamp meter and all connections are clean and tight. Also their should be no other connections to the bank negative except the shunt.

 

[Hoovie]

There are some simple checks which don't need access to any meters and just the VE.Connect app .....
load the App up on the phone. turn on the charger and look at two things:
1) Current
2) Voltage
Charging
If there is no positive current and the voltage is going up, the charger -ve to battery -ve is bypassing the shunt
If there is a negative current and the voltage is going up, the shunt is fitted backwards
If there is no voltage increase the charger is not connected to the battery (or is not working)
Load
Turn off chargers, put on some loads and check current and voltage.
If voltage lowers but current is not negative, Hab Loads are bypassing the shunt.
If current is positive, shunt is reversed.
if voltage doesn't change, hab electrics are not running off leisure battery.

Depending on what you see above will tell you what needs to be fixed.

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[bigtwin]

obvious question .... where did you fit the shunt? photos?

Unfortunately, I don’t have any photos but the shunt is, physically, located immediately adjacent to the original underseat battery. Electrically, it’s connected to the negative post of the original gel battery.

I’ll reply to your second post when I get the opportunity to check things.

Is the shunt fitted the correct way round?

Yes.

Check the leads with a clamp meter and all connections are clean and tight.

This I will do when I’m in a position to remove the seat (we’re currently touring) to gain access to the shunt.

Also their should be no other connections to the bank negative except the shunt.

There are no other connections to the bank negative (other than the interconnect to the second battery) other than the shunt.

Ian

 

[bigtwin]

Charging
If there is no positive current and the voltage is going up, the charger -ve to battery -ve is bypassing the shunt

EHU - There is a positive current and voltage increases.
Alternator - There is no positive current and voltage doesn’t increase (this confirms the symptoms outlined in my OP).

I’ll need to check the shunt wiring for the rogue connection once I can gain access to the shunt.

If there is a negative current and the voltage is going up, the shunt is fitted backwards

EHU - no negative current.

Alternator - negative current (dc loads connected).

If there is no voltage increase the charger is not connected to the battery (or is not working)

EHU - Voltage increases
Alternator - no voltage increase (this confirms the symptoms outlined in my OP).

Load
Turn off chargers, put on some loads and check current and voltage.
If voltage lowers but current is not negative, Hab Loads are bypassing the shunt.

Voltage lowers and current is negative.

If current is positive, shunt is reversed.

Current is negative.

if voltage doesn't change, hab electrics are not running off leisure battery.

Voltage lowers.


I’ll report back once I’ve investigated further.

Ian

 

[Hoovie]

Good feedback for analysis

Looks to me like Smartshunt is connected fine, but your problem is the Split Charge system (B2B or Relay) is not working for some reason.
I am not an "EBL Man" so can't really suggest any specifics, but hopefully with the info you have given, someone like Lenny or Autorouter will know just where to look.



One thought - it could be something as simple as a blown fuse - either the fuse for the power side of the Split charge (there is one on the EBL and should be one on the Starter Battery end of the cable as well), or the D+ fuse. something like a 2A or so fuse. No D+ signal from alternator means no active split-charge on an EBL.
I don't know if the Fridge uses the same D+ signal cable as the Split-Charge system. If so, check if the Fridge is working on 12V when engine running. If not, that would suggest to me D+ Fuse is a likely candidate.

(It is so easy to just blow a little fuse when installing kit and you don't realise until something stops working afterwards).

 

[autorouter]

The SmartShunt is connected as per the instructions (i.e. all charge/discharge sources pass through the shunt with the other side of the shunt connecting directly to the bank negative).

Can you confirm that the battery side of the shunt is connected to the battery negative post, and nothing else is connected to a battery negative post - i'm thinking of the chassis earth here. I know the two negative battery posts will be linked together, and that's fine. But there should be no other wire to the negative battery posts.

 

[bigtwin]

Can you confirm that the battery side of the shunt is connected to the battery negative post, and nothing else is connected to a battery negative post - i'm thinking of the chassis earth here. I know the two negative battery posts will be linked together, and that's fine. But there should be no other wire to the negative battery posts.

I’ll check when I get an opportunity to gain access to the battery/shunt.

Ian

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[bigtwin]

Charging
If there is no positive current and the voltage is going up, the charger -ve to battery -ve is bypassing the shunt

Alternator - There is no positive current and voltage doesn’t increase (this confirms the symptoms outlined in my OP).

I’ll need to check the shunt wiring for the rogue connection once I can gain access to the shunt.

Ok, I’ve investigated further using a DVM/clamp meter with the following results.

Engine off: Starter Bat is 13.4V, Leisure Bat is 12.85V

Engine on: Starter Bat is 13.7V, Leisure Bat is 13.5V

Starter current 20A, Leisure Bat is 5A​

IT 99 display shows 20A charge current (seems odd that this shows 20A and not 5A)​

SmartShunt shows 5A​

These measurements are curious (I’d have expected the larger current to be going to the leisure battery (however, the leisures were at a decent state of charge so that might explain the low (5A) current).
This also confirms that the SmartShunt is connected, and operating, correctly.

EHU off: Starter Bat is 13.4V, Leisure Bat is 12.85V

EHU on: Starter Bat is 13.19V, Leisure Bat is 14.00V

Starter current 0.4A, Leisure Bat is 6.4A​

IT 99 display shows 6A charge current​

SmartShunt shows 6A​

This shows that the alternator is charging the leisure batteries but I find the IT 99 reading curious. I had wondered if the Starter battery and leisure batteries connection to the EBL have been transposed (red mark on attached diagram).

If that were the case, Lenny HB, autorouter:
A - Would things work generally?
B - Might that explain the anomalous IT99 reading?

Ian

 

[bigtwin]

Can you confirm that the battery side of the shunt is connected to the battery negative post, and nothing else is connected to a battery negative post - i'm thinking of the chassis earth here. I know the two negative battery posts will be linked together, and that's fine. But there should be no other wire to the negative battery posts.

Having gained access to the battery, I can confirm that the only additional connection to the negative battery post is the lead to the second battery.

Ian

 

[AdrianChen]

Does the fridge take some of the ebl current?

 

[ChrisL]

If your leisure battery is 12.85 volts off ehu with the engine off then it is fully charged, so I would only expect to see a 5 - 6 amp charge rate, I think the shunt in the EBL is showing alternator output and the shunt at the leisure batteries is showing the actual current input to the leisure batteries.

 

[bigtwin]

Does the fridge take some of the ebl current?

Possibly but I don’t think so. It’d be a pretty poor system if the fridge load limited the battery charge current to a few amps. Perhaps others might have a view on this.

Ian

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[Hoovie]

I would say the EBL current info is telling you how much Current the Alternator is providing, whereas the SmartSHunt is the Net current into or out of the battery.

It would be the same situation as if you were monitoring the Smartshunt and a Solar Controller. The Solar could be reporting 15A coming in but the Smartshunt might say 10A as you have 5A worth of habitation load.

Why the EHU current matches the Smartshunt current I don't know - I can only think the measurement for that is at a different point.

 

[bigtwin]

If your leisure battery is 12.85 volts off ehu with the engine off then it is fully charged, so I would only expect to see a 5 - 6 amp charge rate, I think the shunt in the EBL is showing alternator output and the shunt at the leisure batteries is showing the actual current input to the leisure batteries.

Granted. At the moment it’s well charged but I’ve had the same symptoms after moving off after a few days off grid.

It certainly looks as though the EBL shunt is showing alternator output but that seems a curious thing to show.

Ian

 

[bigtwin]

Why the EHU current matches the Smartshunt current I don't know - I can only think the measurement for that is at a different point.

That seems ok to me. The LAS 1218 charger feed from A8 feeds through the internal shunt and out to the leisure battery and the SmartShunt.

Ian

 

[AdrianChen]

I would say the EBL current info is telling you how much Current the Alternator is providing, whereas the SmartSHunt is the Net current into or out of the battery.







It would be the same situation as if you were monitoring the Smartshunt and a Solar Controller. The Solar could be reporting 15A coming in but the Smartshunt might say 10A as you have 5A worth of habitation load.







Why the EHU current matches the Smartshunt current I don't know - I can only think the measurement for that is at a

Is it aes

different point.

 

[bigtwin]

Is it aes

It is but its/was set manually to 230V.

Ian

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[autorouter]

This shows that the alternator is charging the leisure batteries but I find the IT 99 reading curious. I had wondered if the Starter battery and leisure batteries connection to the EBL have been transposed (red mark on attached diagram).

If the battery voltages are significantly different, as in

EHU off: Starter Bat is 13.4V, Leisure Bat is 12.85V

then that makes it a bit easier. You could start by looking at the display voltage readings to see if they corresponds to the measurements at the battery terminals. In particular, does the leisure battery voltage display correspond to the leisure battery voltage reading at the terminals. The display gets the starter battery voltage by a different route (via Block 2 Pin 1) so the starter battery display won't be affected by the interchanging of the main supply cables.

You can also check this if you can get access to the terminal block at the back of the EBL. The wire colours are not what you would expect in a British van, so there could have been a mixup. On mine it's Red = Starter positive, Black = Leisure positive, Brown = negative. You should be able to tell which battery is connected if their voltages are different. Pulling the 50A fuse next to the battery will confirm this. Terminal block should be labelled, SB = Starter, WB = Leisure (Wohnraum Batterie)

If access is difficult, you could do a preliminary check on the leisure battery voltage at the front panel. The leisure battery connection goes to the Auxiliary Charger (= Zusatz Ladergerat) 2-pin connector, via a fuse with the same label. So insert a fuse and check the Block 7 terminal pin, or even just check the fuse slot terminals.

 

[bigtwin]

You could start by looking at the display voltage readings to see if they corresponds to the measurements at the battery terminals.

The IT 99 readings correlate well and align with the connections on the back of the EBL.

In particular, does the leisure battery voltage display correspond to the leisure battery voltage reading at the terminals

They align.

The wire colours are not what you would expect in a British van, so there could have been a mixup. On mine it's Red = Starter positive, Black = Leisure positive, Brown = negative.

Same as mine.

You should be able to tell which battery is connected if their voltages are different. Pulling the 50A fuse next to the battery will confirm this.

Yes, the Starter battery voltages measure the same at the battery and at the back of the EBL.

I guess that debunks the notion that the wires may have been transposed at the back of the EBL.

Any thoughts on @AdrianChen’s question on the relationship with the fridge?

Ian

 

[autorouter]

Can you confirm that there is a chassis earth connected to the load side of the shunt?

 

[bigtwin]

Can you confirm that there is a chassis earth connected to the load side of the shunt?

Not without the back breaking effort of removing the passenger seat again! A job for another day.

If there was one connected to the battery negative post before I connected the shunt then it, along with all of the other connections, was moved to the load side of the shunt. Would that lead likely be earthed at a point very close to the battery or might it be connected to an earth point some distance away?

Ian

 

[AgeingAndrew]

I would say the EBL current info is telling you how much Current the Alternator is providing, whereas the SmartSHunt is the Net current into or out of the battery.

It would be the same situation as if you were monitoring the Smartshunt and a Solar Controller. The Solar could be reporting 15A coming in but the Smartshunt might say 10A as you have 5A worth of habitation load.

Why the EHU current matches the Smartshunt current I don't know - I can only think the measurement for that is at a different point.

According to the schematic in post #11 the EBL shunt measures all current to and from the LB as long as all charging and discharging is done through the EBL. If any charger or load bypasses the EBL shunt then the EBL shunt will not measure it (but the smartshunt will).

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