CBE CB516 charger - whats the white signal wire?

[arthur49]

Having changed from lead acid to lithium in the past few days, I've had to replace the CB516 charger as its not suitable for lithium. The latter has a white wire going to the CBE DS520AN.

 

I suspect this is a signal wire to switch off the charger should the engine be started with EHU connected or perhaps its the other way round? Disables alternator charging? The instructions say its a Net Presence Signal 12v but I don't understand its function!

 

Anybody know?

[Alanb]

Arthur,

 

The white signal wire of the CBE CB516 has two functions.

 

1. To operate the mains charging relay for B1 (vehicle battery). This relay is at the lower RH corner of the DS520 PCB. The reverse blocking diode, and current limiting (2A) thermistor, (a blue disc) are adjacent.

 

2. To provide the "Mains ON" signal to the PCxxx display unit. The icon on my DS520 is a 2 pin plug symbol.

 

Without the white signal lead you will loose mains charging of the starter battery, and the mains ON indication. An interesting work around that I have viewed recently, was to use a small plug type 12V PSU to feed into the DS520 or DS300. The mains ON output of the CB516 charger is only rated at 50mA, so a 500mA PSU would be more than adequate. The socket into which the PSU is plugged, should not of course be capable of being supplied via an inverter.

 

Alan

[arthur49]

Thank you Alan, glad you came along :-D

 

I noticed no "Mains On" on the panel but I can live without it

 

The new charger, a Votronic 25A, has a starter battery output so I'll use that I think :-D

[arthur49]

Alan

 

Alternatively I could use one of these

 

https://www.amazon.co.uk/Miniature-Driver-Constant-Voltage-TGR-12V-6W-B/dp/B093C2CFYC/ref=sr_1_13?dchild=1&keywords=12v+500ma+power+supply&qid=1622533834&sr=8-13

 

The 230v mains input could be taken from the charger input. Connect the output to the white signal wire. That way full functionality of DS520 will be restored?

 

WDYT?

 

Arthur

[Alanb]

Arthur,

 

Given that your new charger has a starter battery output, it may be simpler to use that. If the habitation and starter battery outputs are commoned at the negative terminal(s), you would only have to run one extra wire, to the B1 +ve terminal of the DS520.

 

Sizing for the new wire is more problematical. Depending on the appropriate charger output, it may be that only 0.5 sq mm is required, however this would need fusing close to the B1 terminal. The alternative would be to make the wire of sufficient csa, so as to be protected by the existing B1 fuse. Also any recommendations in charger instructions?

 

If opting for the PSU, there is also the mains input to connect. I would also consider the safety angle. With battery chargers and PSUs there is always the slight risk of an input to output failure, possibly due to supply surges. While I like the look of the "Tiger" unit, the internal construction is an unknown. What I would like to see would be slots in the PCB under the internal transformer. Alternatively a PSU designed to supply a telephone should be OK.

 

Alan

[arthur49]

Thank you Alan.

 

I'll go for the charger output for starter battery option as that's simpler.

 

The Votronic charger (PB1225 25a) instructions suggest 1.5 - 2.5mm2 cable for starter battery connection and since B1 is only 30cm or so away I'd have thought 1.5mm2 would be OK.

 

Instructions also state to fuse at 15A ............. but it also states "....the output voltage is slightly lower than the output voltage of the main charging port, and its current intensity is limited to approx. 2 A or 3 A"

 

Main charging port output on lithium is 14.4v

 

So a 15A fuse seems a bit high to me. 5A should be adequate?

 

Really appreciate your expertise and help :-D :-D

[Alanb]

Arthur,

 

I agree with your suggestion of a 5A fuse. This would in theory allow only 1/9 of the energy that a 15A fuse would pass into a fault. ( Its a current squared x time thing.)

 

You can keep an eye on the fuse by checking the starter battery voltage via the CBE display when on EHU. It should show 13.2V or more.

 

I suggest using a blade fuse, so that you will have common spare with those for your DS520.

 

Inline/single blade fuse holder that you can terminate wires to are available in various forms.

 

Alan

 

[arthur49]

Cheers Alan :-D :-D

[arthur49]

Well Alan, everything's installed and set up for lithium and working fine including starter battery charging using the output on Votronic battery charger.

 

BUT, on running engine initially there is a clicking coming from the DS380. This does not last long, possibly 10 seconds but sounds to me like the relay contacts in DS380 and the coil is being partially energised? I'm not sure what happens on electric hook up, certainly by the time I've connected EHU lead and gone inside, all is quiet!

 

So it looks like the DS380 does not like the white signal lead disconnected. We're off in a few days. When we come back I'll install the 12v 100ma PSA workaround you suggested

[Alanb]

Arthur,

 

Are you referring to the PC320 control panel, or the DS520 distribution board? I have no experience of the PC320, but I doubt that it would contain relay(s), unless required to interface with the DS520.

 

I would need full details off your 12V installation, in order to even make a guess at the cause of your clicking.

 

The only similar problem that I have experienced in the past, was an alarming oscillation in engine rpm when starting. This was after I had moved control of the step autoretraction to simulated D+. The problem was due to the converter having connected the DS520 to D+ instead of IGN +ve, as specified in the CBE instructions.

 

Alan

[arthur49]

Sorry Alan, I mean the DS520 (don't know where 380 came from )

 

I'm heading off shortly and I'll see how it goes :-D :-D

[Alanb]

Arthur,

 

Please do not be too hasty in adding a replacement for the "S signal" (white wire), input to your DS520. I do not think that your interpretation of the clicking noise, being caused by a partially operated relay is correct. More probable is the repeated operation and release of the CBE split charge relay.

 

If I remember correctly you have a smart alternator, which was compensated for, by adding a B2B feeding into the B1 (starter battery input), of your DS520. From this I infer that the split charge and fridge relays on the DS520 PCB, are still in use. Is the B2B triggered by the CBE simulated D+? I have not confirmed if the following applies to CBE systems, but voltage monitoring circuits typically include a short time delay to prevent operation being caused by short term fluctuations in the supply.

 

I am hypothesising that what is happening, is that your 12V system is oscillating until the B2 (habitation battery) voltage rises sufficiently.

 

Alan

[arthur49]

Well Alan, its clicks no more!

 

I had to use an uninsulated spade terminal to connect fuse holder to charger output. In routing this cable it looks like the uninsulated spade terminal was intermittently touching the charger case and possibly shorting. The charger has protective circuits inside and I suspect I was hearing them activating? The charger and DS520 are adjacent - difficult to determine which was making the clicking.

 

Anyway I've insulated the spade terminal and rerouted the cable with conduit protection and ................ no clicking!

 

I'm usually extremely careful in my DIY. On this instance it appears I failed ................. :-S :-S

[arthur49]

Alan

 

Clicking persists. Its coming from DS520AN and with a finger on relay seems its not happy. Occurs on start up only. Not a rapid clicking, but continues for say 10-15 seconds. On most occasions, not all. Whilst I'm a competent tickerer having been doing so for years, narrowing the cause down is not my forte!

 

Vehicle is fitted with a smart alternator and by using a voltmeter in accessory socket on dash I've witnessed the starter battery voltage with engine running swinging from 15.2v to just over 12v.

 

As suggested by the late Allan Evans, I put a Schaudt B2B (WA121545) in the feed between starter battery and DS520AN. This works really well but I've only just noticed the clicking on start up after I fitted lithiums!

 

I attach a schematic of system from starter battery to DS520AN input. I've not shown the leisure batteries but these are connected via busbars and fusing to B2 + and -

 

I wonder if placing all the negatives on B2- is causing an issue for the B2B. Its seeing the + from starter battery but - from leisure battery?

[Alanb]

arthur49 - 2021-07-06 12:36 PM

 

Alan

 

Clicking persists. Its coming from DS520AN and with a finger on relay seems its not happy. Occurs on start up only. Not a rapid clicking, but continues for say 10-15 seconds. On most occasions, not all. Whilst I'm a competent tickerer having been doing so for years, narrowing the cause down is not my forte!

 

Vehicle is fitted with a smart alternator and by using a voltmeter in accessory socket on dash I've witnessed the starter battery voltage with engine running swinging from 15.2v to just over 12v.

 

As suggested by the late Allan Evans, I put a Schaudt B2B (WA121545) in the feed between starter battery and DS520AN. This works really well but I've only just noticed the clicking on start up after I fitted lithiums!

 

I attach a schematic of system from starter battery to DS520AN input. I've not shown the leisure batteries but these are connected via busbars and fusing to B2 + and -

 

I wonder if placing all the negatives on B2- is causing an issue for the B2B. Its seeing the + from starter battery but - from leisure battery?

Hi Arthur,

 

I have just noticed your posting quoted above. I remember your thread concerning smart alternators and that you wired your B2B via the B1 +ve terminal of the DS520.

 

Wasn't this method of connection suggested by Allan for simplicity?

 

With this method of connection, the B2B output is routed via the DS520 internal split charge relay.

 

I think that perhaps there is an error in your drawing and that it should show the B2B output connected to the B1 +ve terminal of the DS520.

 

The DS520 provides a simulated D+ by taking an IGN + supply and monitoring it. My CBE manual gives a cut in, or pick up voltage of 13.3V and a drop off voltage of 12V; time delays are not mentioned. Given some tolerance the nominal 12V drop off could be above your alternator minimum. The simulated D+ drives the internal split charge and fridge relays.

 

This means that when your alternator starts generating and the voltage exceeds 13.3V the split charge relay closes, a step load approaching 50A could be placed on the alternator. Since lithium batteries have a lower internal resistance than lead acid, the step load will now be at a maximum, assuming that the maximum is limited by the B2B. This load will conceivably cause a drop in system voltage, and if the voltage falls low enough for the simulated D+ to be interrupted......... Does the engine rpm rise and fall?

 

I do not think that the arrangement of the negatives is a contributing factor, but my fastidious self would have wired the starter battery negative direct to the B2B. That arrangement would make a neater drawing and installation.

 

If the above hypothesis is correct, then there may be alternative cures, but they would probably involve additional relays being installed. How is the B2B controlled?

 

Alan

[arthur49]

Yes Alan, sorry, + output of B2B is to B1+ on DS520 (two many 'B's' makes it confusing!). And yes, the configuration was suggested by the late Allan Evans.

 

The B2B is driven by the simulated D+ on DS520.

 

Its only when I drew schematic that I realised all the - at B2-. I'll alter that, if only to make schematic look better.

 

Incidentally, on my van, Wildax drive the fridge off the starter battery via a dedicated relay. The clicking is still there with the fridge off.

 

I've not noticed the engine revs rise or fall on start up. As I said previously, the clicking exists only at start up, and for a short time, but my concern is what thats doing to the relay contacts. Its not a rapid clicking but continues until, what seems to me, the voltage stabilises.

 

The B2B can be set for what Schaudt call "Power Reduction". Mine was set so that no charge would come from B2B if input voltage dropped below 11.8v. This can be altered to 11.2v so I'll set it at that to see if that makes a difference. I've not noticed the starter battery voltage drop as low as 11.8v but if that happens even momentarily the B2B output stops and therefore the DS520 split charge opens (and simulated D+ ceases). This "Power Reduction" can also be set to not charge under 12v.

 

If all else fails I'll re-install B2B in the conventional manner.

 

Thank you for your (ongoing) help Alan

[arthur49]

Just an update on this.

 

Today I pulled fuse between starter battery and B2B, started engine and noted voltage at starter battery dropped momentarily to 11.6v. Voltage fluctuated a bit for 10 secs or so then settled at 13+v. Being a smart alternator it doesn't deliver a steady 14.4v but on the road I've noticed it as high as 15.2v.

 

So, with the B2B putting no load on the alternator, the voltage at starter battery dropped to 11.6v, the threshold at which the B2B stops charging. I've not checked what it drops to with the B2B connected but momentarily it could be lower? So I'll set the B2B to stop charging at 11.2v, so hopefully it will stop the clicking from DS520.

 

I suspect therefore this momentary voltage drop is causing the B2B to switch on and off, in turn preventing the DS520 split charge closing, and staying closed, so it clicks on and off.

[Alanb]

Alanb - 2021-07-07 7:33 PM

 

=====================================================================================

 

The DS520 provides a simulated D+ by taking an IGN + supply and monitoring it. My CBE manual gives a cut in, or pick up voltage of 13.3V and a drop off voltage of 12V; time delays are not mentioned. Given some tolerance the nominal 12V drop off could be above your alternator minimum. The simulated D+ drives the internal split charge and fridge relays.

 

=====================================================================================

 

Alan

Arthur,

 

I think that you have not picked up on the most important part of my previous post, which I have repeated above.

 

The point that I wish to emphasise is that the DS520 will still monitor the alternator/starter battery voltage, and chop the B2B output at the split charge relay. I do not know if there is any drop off delay for the DS520 simulated D+, but I suspect not, as it would not have been a requirement at the design stage, when ti voltage would be expected to remain higher than 13.3V until the ignition switch was turned OFF, giving immediate interruption to the ignition + feed to the DS520 (blue? wire).

 

I am surprised that your fridge is supplied directly from the starter battery. Perhaps I have not remembered correctly, but I thought that poor fridge performance on 12V was the initial reason for the B2B, and that the fridge would benefit from the enhanced B2B output connected to the B1 terminal of the DS520.

 

How is the Wildax fridge relay controlled?

 

One possible fix may be install an ignition switch repeat relay. Cut the blue wire at a suitable point, and divert the supply side to the coil of a small relay, with the remote end of the coil connected to earth. Supply NO contact (87) of the relay perhaps via a small (5A) fuse, and connect C contact (30) to the DS520 end of the blue wire. The DS520 simulated D+ is still controlled by the ignition switch, but it is the B2B output voltage that is monitored.

 

As your fridge is not connected via the DS520, you have the option of moving the B2B output to the DS520 "+ OUT 12V" terminal. This will improve charging, by removing the split charge relay from the charging circuit, and should be a relatively simple move.

 

Alan

[arthur49]

Hi Alan

 

Let me start with the easy bits first.

 

The fridge is definitely driven from starter battery. Its shown on the (handwritten) schematic I got from Wildax. The starter battery on my Master is in the passenger footwell. There is a 20A fuse under the passenger seat but I've not actually seen the relay .... but I've never looked for it. I've just assumed the fridge relay is driven by engine run or ignition on signal - its not shown on schematic.

 

The fridge performance was not the reason for the B2B, the reason was the poor charging of leisure batteries and potential for these to drain into starter battery.

 

I mentioned the fridge at the outset of owning this van because it started beeping when we stopped at lights for example. Stop/start cut in, the fridge got no juice and objected. So my cure for that is to switch off stop/start :-S

 

I had to read the other techie bit a few times. I think I understand it :-D I really don't want to fiddle with the inside of the DS520.

 

I have a 30 mile trip to do tomorrow so I'll take the van and see if the adjustment I made to B2B eliminates the clicking. If not, I'll put output onto "+Out 12v" - I'd not thought of that possible solution so thank you - and that is an easy change.

 

I'm really happy with the charging. B2B is giving the batteries approx 45A ......... its the infernal 10-20 seconds of clicking at start up thats spoiling it!

[arthur49]

I've got it Alan..... I think. Sorry I'm slow to get it!

 

The ignition signal which triggers D+ is receiving a variable voltage as a 45A load on start up is generated by B2B. That variation means the D+ is switching on and off leading to the split charge coil opening and closing.

 

I still don't want to fiddle with DS520 internals though. Last resort I think.

 

If I put the B2B output to OUT+12v is the associated circuitry in DS520 capable of handling 45A? I know the split charge relay is rated at 70A so its associated circuitry must be capable of at least 45A. (Wildax cabling is rated at 70A with power fusing at 50A)

 

And thank you for your help

[Alanb]

 

"The ignition signal which triggers D+ is receiving a variable voltage as a 45A load on start up is generated by B2B. That variation means the D+ is switching on and off leading to the split charge coil opening and closing."

 

YES that is my thinking.

 

"I still don't want to fiddle with DS520 internals though. Last resort I think."

 

I was NOT suggesting any modification to the DS520. The relay would be external.

 

"If I put the B2B output to OUT+12v is the associated circuitry in DS520 capable of handling 45A? I know the split charge relay is rated at 70A so its associated circuitry must be capable of at least 45A. (Wildax cabling is rated at 70A with power fusing at 50A)"

 

Your present arrangement has the B2B output passing through more of the DS520, than if you were to move the connection.

 

Given that you move the B2B output as proposed, I am wondering what the simulated D+ will be needed for?

You would not be using the integral split charge, and fridge relays.

 

Are there any external connections to the DS520 simulated D+ output, via the blade connectors on the RHS of the PCB, i.e. FA4, and FA6, the centre position, FA7, is not populated on my DS520.

 

If there are no external connections to these blades then the simulated D+ will not be needed. In this case you could disconnect the blue wire (ignition + input) by pulling the 2 pole connector 26A, or the red connector 26B (alternative connection options). See CBE Manual pages 17 & 18 for more detail.

 

On the other hand if Wildax have connected to the FA4 & FA6 points, for the fridge relay, and auto electric step retraction if installed, then you may have to adopt my relay suggestion.

 

May I repeat that the suggested relay modification does NOT involve any modification to the DS520. I also am not in favour of modifications to the PCB. I am dismayed when I read reports of track cutting, and even worse mangling the split charge relay when a B2B is installed. However I did not agree with Allan Evans argument, that no action was required.

 

Alan

[arthur49]

Thank you Alan. I'll let you know how I get on

[arthur49]

A big thank you Alan for all your help and advice.

 

I installed a small relay today in the Ign+ line as suggested ...... and no clicking!

 

I looked at simply connecting B2B output to "Out" but the electric step had a supply and a fridge connection, so for the latter I'm confused. But that does not matter, as everything works, and no clicking

:-D :-D :-D