Sterling B2B not working as I thought can anyone help?

[wuzzlewood]

I had a Sterling BBS1230 fitted by my local autoelectrician in order for me to take a long trip around Germany.

We are crossing in a few days and spending the time waiting at a campsite near family to test things out.

When first fitted the solar part did not seem to work so as a temporary measure I reinstated the Truma charge controller.

I installed the Sterling remote control in the hope it would provide more info but I can’t see it offering much!

I have a 2021 Bailey with smart alternator and never had a fully charged Liesure battery unless on hook up and once unplugged it ran down in less than an hour!

New battery fitted under warranty and the Sterling unit fitted with the ignition wire installed as recommended for Euro 6+ engine.

The Sterling unit now kicks in when we are on hook up, ignition OFF! Is tbis to be expected?

Also the temperature sensor is reading up to 55 degrees c but when I felt the battery it was cold!

Things don’t seem right to me, is it safe do you think?

Should I switch it off at the unit!

I still have the D+ signal connected and the alternator still charges alongside the Sterling for what that is worth and to allow fridge to work on 12v.

I am afraid it isn’t right and could overhear or cause a fire. I really expected the unit to do nothing when we are parked up as solar is NOT connected!

Thanks in advance
Steve

 

[JockandRita]

I had a Sterling BBS1230 fitted by my local autoelectrician in order for me to take a long trip around Germany.

We are crossing in a few days and spending the time waiting at a campsite near family to test things out.

When first fitted the solar part did not seem to work so as a temporary measure I reinstated the Truma charge controller.

I installed the Sterling remote control in the hope it would provide more info but I can’t see it offering much!

I have a 2021 Bailey with smart alternator and never had a fully charged Liesure battery unless on hook up and once unplugged it ran down in less than an hour!

New battery fitted under warranty and the Sterling unit fitted with the ignition wire installed as recommended for Euro 6+ engine.

The Sterling unit now kicks in when we are on hook up, ignition OFF! Is tbis to be expected?

Also the temperature sensor is reading up to 55 degrees c but when I felt the battery it was cold!

Things don’t seem right to me, is it safe do you think?

Should I switch it off at the unit!

I still have the D+ signal connected and the alternator still charges alongside the Sterling for what that is worth and to allow fridge to work on 12v.

I am afraid it isn’t right and could overhear or cause a fire. I really expected the unit to do nothing when we are parked up as solar is NOT connected!

Thanks in advance
Steve

Hi wuzzlewood.

I was hoping that someone with more electrical knowledge than myself, would have responded by now.

I have the Sterling B2B 12/12 60A unit installed, and also set up for ignition feed. The only time it comes to life, is when the engine is running, and a couple of minutes after the alternator becoming functional, ie, when the starter battery has reached that magic voltage, for the B2B to kick in and charge the leisure bank of batteries.

I wish I had £20 for every time I have read through the instructions, which I keep close to the unit.
It certainly should not start up without receiving a D+ signal.....................unless it has been set up alternatively.

Due to the age of the MH, I don't have a smart alternator, so programming the B2B was very easy using the two buttons on the front panel.
Because of the CBE charging regime, I did need to get an auto electrician to install a NC (Normally Closed) relay, which disconnects the charge from the alternator to the CBE charging unit, thereby allowing the B2B to do it's job properly. All has worked well since installation back in late 2020, as did a B2B 12/12 50A, in a previous MH installation.

Have you programmed your B2B/BBS to cater for regeneration braking?

I know nothing of the solar aspect of your BBS 1230A, as all my panels are wired direct to Votronic solar controllers.

Sorry I can't answer all your questions, but if in any doubt at all re safety, isolate things until you are happy with it's correct installation, programming, and functioning.

Good luck getting it sorted

Jock.

 

[peterc10]

The wiring is probably not correct. First thing is to check with Bailey if it has already got a B2B charger, as most motorhomes with a smart alternator usually have.

If not then check up to make sure that the electrician has disabled the existing charging relay. If they have not that will always mean you have a permanently live link between the engine and leisure batteries, whether the D+ is on or not. Also make sure that the B2B is set on to D+ switching, and not difference in battery charges.

I am afraid that most "auto" electricians do not understand the more complex nuances in motorhomes' habitation electrics.

 

[JockandRita]

I am afraid that most "auto" electricians do not understand the more complex nuances in motorhomes' habitation electrics.

I would go along with that statement Peter.
Fortunately for me, my auto electrician is also a caravanner, and he does the electrical jobs on his father's MH.

He did identify a problem with the F/F connection, and put that right for me.

Cheers,

Jock.

 

[Two on Tour]

Are you sure that it is wired for D+ and not as "automatic activation"

If it's wired for "automatic activation" and your mains charger also charges your starter battery, then the starter battery charge voltage to the battery will trigger the B2B.

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[autorouter]

Sterling B2Bs have three modes of working. 1. Voltage threshold activation only mode. 2. Voltage threshold activation plus D+ to keep it activated when the voltage drops low but the engine is running, for example with a smart alternator. 3. D+ activation only, no voltage threshold activation.

I have my B2B in the third state. Sorry, going out now, I'll be back later with more details.

 

[Pausim]

I suspect your auto electrician has wired it for voltage activation, in which case it will turn on when it shouldn’t. It needs to be wired for D+ activation, which means it will only turn on when the engine is running. Voltage sensing is also no good with a smart alternator, the B2B will spend a lot of time turned off. An auto electrician should know this but…………….

 

[autorouter]

Sterling B2Bs have three modes of working. 1. Voltage threshold activation only mode. 2. Voltage threshold activation plus D+ to keep it activated when the voltage drops low but the engine is running, for example with a smart alternator. 3. D+ activation only, no voltage threshold activation.

I have a Sterling B2B with the the 'Green Stripe' across the front, which shows the firmware version of V69 or later. The manual describes two modes, Mode1 and Mode 2, which are what I called 1 and 2. If no wire to the 'Ignition' terminal of the B2B, then Mode 1. If the D+ wire to the 'Ignition' terminal is present, then the default is Mode 2. Note that in Mode 2 the B2B will turn on if the voltage rises above the threshold for any reason, which is what I think is happening in this case.

There is a third mode which the manual calls 'Pure Ignition Mode', which can be set by pressing the 'Setup/Enter' button for more than 40 seconds. Yes, 40 seconds. It seems to deactivate the Voltage Threshold trigger, so in contrast to Mode 2 it will not turn on if the voltage of the starter battery rises above the threshold voltage (by a solar charger or a battery maintainer for example). Like Mode 2, this mode also needs the D+ wire connected to the 'Ignition' terminal of the B2B.

I still have the D+ signal connected and the alternator still charges alongside the Sterling for what that is worth and to allow fridge to work on 12v.

The alternator should not charge alongside the Sterling. If there's a split charge relay, then that is in effect a direct metal contact between the two batteries, to allow the alternator to charge - or not - both starter and leisure batteries. This will short the input and output of the B2B, stopping it from doing its job. The whole point of the B2B is that it should take power at about 12.5V from the alternator, and boost it to about 14.5V to give the leisure battery a proper charge. If the split charge relay is still switching on, then it can't do that, it stays at 12.5V, failing to charge the leisure battery properly as you found.

In this situation there really is no substitute for measuring the battery voltages at the battery terminals, with the engine stopped, and with the engine running. You can get a suitable meter at any DIY store for a tenner or so, and it's fairly easy and safe to take voltage readings from a battery.

For example, it may be that both batteries are at about 12.5V when the engine is stopped. When the engine is running, the voltage of the starter battery may or may not go up, but the voltage of the leisure battery should go up to at least 13.5V, and gradually rise to about 14.5V over time. If it doesn't then the B2B isn't working as it should.

 

[wuzzlewood]

I have a Sterling B2B with the the 'Green Stripe' across the front, which shows the firmware version of V69 or later. The manual describes two modes, Mode1 and Mode 2, which are what I called 1 and 2. If no wire to the 'Ignition' terminal of the B2B, then Mode 1. If the D+ wire to the 'Ignition' terminal is present, then the default is Mode 2. Note that in Mode 2 the B2B will turn on if the voltage rises above the threshold for any reason, which is what I think is happening in this case.

There is a third mode which the manual calls 'Pure Ignition Mode', which can be set by pressing the 'Setup/Enter' button for more than 40 seconds. Yes, 40 seconds. It seems to deactivate the Voltage Threshold trigger, so in contrast to Mode 2 it will not turn on if the voltage of the starter battery rises above the threshold voltage (by a solar charger or a battery maintainer for example). Like Mode 2, this mode also needs the D+ wire connected to the 'Ignition' terminal of the B2B.

The alternator should not charge alongside the Sterling. It is in effect a direct metal contact between the two batteries, to allow the alternator to charge - or not - both starter and leisure batteries. This will short the input and output of the B2B, stopping it from doing its job. The whole point of the B2B is that it should take power at about 12.5V from the alternator, and boost it to about 14.5V to give the leisure battery a proper charge. If the split charge relay is still switching on, then it can't do that, it stays at 12.5V, failing to charge the leisure battery properly as you found.

In this situation there really is no substitute for measuring the battery voltages at the battery terminals, with the engine stopped, and with the engine running. You can get a suitable meter at any DIY store for a tenner or so, and it's fairly easy and safe to take voltage readings from a battery.

For example, it may be that both batteries are at about 12.5V when the engine is stopped. When the engine is running, the voltage of the starter battery may or may not go up, but the voltage of the leisure battery should go up to at least 13.5V, and gradually rise to about 14.5V over time. If it doesn't then the B2B isn't working as it should.

Thank you, and everyone else for the help and advice!
I need to find out how to stop the alternator charging. I am away at the moment so unable to go back to the auto electrician for two months!
I will do some research!

 

[JockandRita]

I need to find out how to stop the alternator charging.

Hence the intervention I (and many others on here), have had done, when a B2B has been added.

Because of the CBE charging regime, I did need to get an auto electrician to install a NC (Normally Closed) relay, which when activated, opens and disconnects the charge from the alternator to the CBE charging unit, thereby allowing the B2B to do it's job properly.

The advice about a B2B possibly already installed in the 12v charging system, as part of the original build, is a valid one where a smart alternator is fitted.

Cheers,

Jock.

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[The Artilleryman]

As far as I can tell, if you have a Truma mppt solar controller fitted (when built) it will have a B2B charger fitted as well. It's normally fitted in the bottom of the wardrobe, behind the front passenger seat - for those that have a wardrobe at the front - on other models, I don't know where they hide the electrics.
Best thing to do, is trace the 2 battery leads - one is fed by the PDU and hopefully the other will lead you to the fitted B2B.
As mine is a 2017 model it's non-smart and a pain to get to the wiring - I've had to take off the wardrobe door panel complete to get to mine.
You may find the 2 red cables from the hab battery just disappear into the harness.

Sorry I can't be more help.

 

[Stealaway]

Just the other day I tested my Sterling B2B on my Euro6 Fiat by turning of the solar panels and driving through Germany for an hour.
I have two extra voltage meters between the seats.
The leisure battery quickly climbed to 14.5v the starter battery maintained 14.6. all good.
Turning the solar back on took the voltage to 14.7.
I'm never on EHU so I can't comment on the B2B behaviour.
My system seems to take the highest voltage as priority.
All I know is that the batteries all seem to be fully charged when I stop ---- every night

 

[wuzzlewood]

As far as I can tell, if you have a Truma mppt solar controller fitted (when built) it will have a B2B charger fitted as well. It's normally fitted in the bottom of the wardrobe, behind the front passenger seat - for those that have a wardrobe at the front - on other models, I don't know where they hide the electrics.
Best thing to do, is trace the 2 battery leads - one is fed by the PDU and hopefully the other will lead you to the fitted B2B.
As mine is a 2017 model it's non-smart and a pain to get to the wiring - I've had to take off the wardrobe door panel complete to get to mine.
You may find the 2 red cables from the hab battery just disappear into the harness.

Sorry I can't be more help.

The Truma controller is not an MPPT one.
My van seems to from a run that had Smart Alternators fitted but Bailey refused to acknowledge there was an issue.

They subsequently went on to fit Schault battery balancers, which I understand is a sort of German for B2B.

Mine has the issues associated with the smart alternator but Bailey keep telling the Warranty people, “ never heard of that, go away “!

I have since changed the Sterling unit to work ONLY when there is an ignition feed live(mode 2 I think it is referred to).

That has sorted out the odd behaviour when on hook up.

The solar of the Sterling BBS 1230 is now reconnected and seems to work ok most of the day!

The issue I now get is in low light conditions the input voltage is 18v but the output voltage is lower than the hab battery at about 12.3v and it seems to pull the battery voltage down.

I have spoken to Sterling who tell me that, “ that cannot happen”.

I am away on holiday next week I will see what happens but evidence to date is not encouraging I must admit!

£700 spent in total and NO progress at least as far a battery charge and ability to live “off grid” for even one night is concerned.

Thanks for you help though, I keep my fingers crossed!

 

[The Artilleryman]

My van seems to from a run that had Smart Alternators fitted but Bailey refused to acknowledge there was an issue.

Mine has the issues associated with the smart alternator but Bailey keep telling the Warranty people, “ never heard of that, go away “!

Yes, Bailey do seem to bury there heads in the sand when it comes to design problems.
They were STILL fitting the overcab skylight with the wrong seal 2 years after mine was replaced due to high pitch whistling noise due to it not fitting correctly.
Also the no. of re designs for the top locker clam shell doors - very heavy and self opening on slightly uneven roads.

 

[autorouter]

My van seems to from a run that had Smart Alternators fitted but Bailey refused to acknowledge there was an issue.

They subsequently went on to fit Schault battery balancers, which I understand is a sort of German for B2B.

I can't find any information on a Schaudt battery balancer. Maybe it's the Schaudt Booster, like the WA 121525, which is what we call a B2B on here. A battery balancer, for example the Victron one, is used to equalise the voltages of two or four batteries connected in series (24V or 48V), like a BMS in a lithium battery, and is not something you would fit in this situation.

The solar of the Sterling BBS 1230 is now reconnected and seems to work ok most of the day!

The issue I now get is in low light conditions the input voltage is 18v but the output voltage is lower than the hab battery at about 12.3v and it seems to pull the battery voltage down.

I have spoken to Sterling who tell me that, “ that cannot happen”.

The Sterling BBS 1230 is a relatively recent development, a 30A B2B with an MPPT solar input. I think what Sterling meant is "that cannot happen" if it is wired up correctly. If you look in the Schaudt WA121525 Booster manual (page 4, Generatorvoltages) they say that without a booster there is a risk that a fully charged leisure battery will discharge to the starter battery until they have equalised, if the standard split charge relay is still operational. Or an extra bypass relay, as in their diagram, has been wired incorrectly.

This is one of those situations where trying to deduce flows of current (amps) by looking at voltages and voltage differences is a bit difficult. It's better to use a clamp meter to measure the current flow directly and unambiguously. If you could say for example that there was 1.6A out of the leisure battery, and 1.5A into the starter battery, then there would be no argument that something wasn't right. The point is, all these things are measurable to an auto electrician with suitable tools. If you had a clamp meter you could measure it yourself.

But don't rush out and buy the cheapest clamp meter you can find, a lot of them only measure AC current, not DC current as required here. Some even say AC/DC Clamp meter on the packet, but that's voltages, they often don't measure DC current.

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