Hymer electrics major? problem and a condundrum (1 Viewer)

[veevee]

Hymer B680 Built 2005 on a MB 416CDI

Preparing to fit 3 new batteries today and a couple of things occurred.

Yesterday evening removed the original 2 habitation batteries but only after disconnecting the electric hook up, switching the mains fuse off, switching 12v off on the control panel and switching the battery off switch on the Elektroblock, so no power to the habitation part of the vehicle.

Removed the hab batteries and decided to check if the was some form of residual voltage across the + and - battery clamps. To my surprise there was 6.3v.

As everything disconnected wasn't worried although it kept nagging at me, but we have a lot to do at the moment so got on with other things.
This afternoon went back to the job of drilling holes in the sub-floor battery box ready to take the wet batteries breather tubes. Decided to check the voltage again at the disconnected hab battery clamps and now have 9.1v, then it clicked, the starter battery is still connected to the vehicle section and although no expert thought that unless charging there is no connection between the two types of battery. Afterthought : that's not strictly true, at the rear of the EBL101 the negative leads from both the starter and hab batteries connect into the same terminal, the positives into separate ones.
Removed the 50A and 2 A fuses in the engine compartment protecting the EBL from the starter battery and voltage fell to nil at the hab battery terminals, so although nothing was on at all apart from Sprinter dash instruments in the background, voltage was transferring (although not full battery voltage of 12.8v that I later measured) to the disconnected battery terminals of the hab batteries.

How can that happen? I'm a bit bothered that there is either an Elektroblock fault and/or there is a permanent drain on the starter battery. The starter battery has been charged by the EBL up until a little over 24 hours ago, I expected that this new powerful battery would have read slightly higher than 12.8v after such a short time.

3 weeks ago the original starter battery failed dramatically over a few days, the current battery has been fitted for around 10 days.


The conundrum.

The 2 fuses just before the hab batteries are sat in a double housing, again 50A and 2A - photo 1.

The grey 2A fuse is sat in some form of adapter/extension - photo 2

It isn't an adapter at all but a second 2A fuse - photo 3

The see through cap for the lower fuse/adapter (between the upper and lower grey fuse) was found at the bottom of the battery box, someone had mistakenly fitted a second fuse - photo 2 - into the top of the first lower fuse. Both fuses were intact but how could that happen?
I guess apart from adding a little resistance by having a second fuse no harm was done.

Thank you

 

[TheBig1]

have you a solar panel fitted, and did you remember to pull the solar feed fuse before disconnecting the batteries?

 

[pyro]

The two fuses are in parallel, not series, so the resistance would be halved (all things being equal)

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[veevee]

No Big1, solar is to be fitted after I have added a 3rd battery. As there had been this rapid starter battery failure I decided to replace and check step by step and wouldn't fit solar until all the rest was ok.

What I didn't mention was the two starter battery cables chafed against the edge of the seat frame under the driver's seat, had been happening for a while. When I found the starter battery with 5.3v one morning I followed the EBL starter battery charging cables to the back of the EBL, then a puff of smoke and I started moving fast. Photos were taken after all batteries were disconnected if you want to see some poor design and workmanship (from Hymer).

 

[TheBig1]

given no solar input, i suggest you have a short between a leisure circuit and the cab battery. disconnect the -ve lead on the cab battery to be safe as you work and inspect the wiring at the ebl

 

[veevee]

given no solar input, i suggest you have a short between a leisure circuit and the cab battery. disconnect the -ve lead on the cab battery to be safe as you work and inspect the wiring at the ebl

When I found the starter battery charging cables chafing checked all the external cables under the seat too. Although there were a couple with the lightest of marking nothing disconnected or loose, but I did extra insulate more of the under seat cables that looked vulnerable.
Yes, that work was done with all the batteries disconnected, but thanks for the reminder.

My (financial) worry is there is a problem inside the EBL 101, just wondered if anyone else had bothered to check for voltage at the battery terminals when the hab batteries are removed. I'll try to find the EBL wiring diagram today and read through that, there may be a clue there.
One thing is for certain, the voltage at the hab battery terminals disappeared immediately I disconnected the engine bay fuse, so that looks like the likely source of power which narrows it down.

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[veevee]

Have this morning re-fitted the two fuses into the EBL charging cables in the engine bay, first one and then the other and last both together. No voltage recorded at the hab batteries clamps at any time using the 2v scale to 3 decimal places...
Has now stood for 30 minutes with all fuses connected, still no voltage shown.

 

[filopastry]

Daft question I recon but, is there a capacitor somewhere in the circuits ??? Forgive me if it's a daft question, but I remember once disconnecting a strip light completely from the power and still getting a shock, surprised the hell out of me

 

[berni109]

U mentioned a puff of smoke in 1 post, where did that originate?
The 2 amp fuse is for the boiler water dump valve or at least it us on mine (not hymer) and u should mot be seeing any voltage out of the 50amp fuse with no leisure battery but then I guess u already know that.

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[veevee]

Daft question I recon but, is there a capacitor somewhere in the circuits ??? Forgive me if it's a daft question, but I remember once disconnecting a strip light completely from the power and still getting a shock, surprised the hell out of me

Good point jetlag03, but I don't know the answer

U mentioned a puff of smoke in 1 post, where did that originate?
The 2 amp fuse is for the boiler water dump valve or at least it us on mine (not hymer) and u should mot be seeing any voltage out of the 50amp fuse with no leisure battery but then I guess u already know that.

Under the driver's seat at the rear of the EBL, see the following photos -

The electrical set-up with the seat removed. Notice one of the silver screw heads is rust brown (bottom right of center), all the others still have their original coating

From the opposite side with the auto box computer moved to one side and the front support bar for the computer removed

Close-up of the 10mm2 Black + and Brown - cables originating at the rear of the EBL running directly to the 2 hab batteries. There is a 50A fuse in the line as the cables emerge in hab battery box, this fuse was not blown. The second 10mm2 Brown cable and the matching Red cable (charging cables for the starter battery) were singed but the insulation for these had not been damaged.

A clearer photo showing the cables had about 50% burnt away and the fuse didn't blow, is it too high a value? Also have to say that for some reason it looks as though this has happened over a long period of time, and the fact that it had only travelled 8000 miles before we bought it meant that the chafing had happened slowly. Only after trying to find the reason for the starter battery to suddenly expire did I gently try to move the cables under the seat and saw the puff of smoke.

In reality we got lucky, if this had made a good contact with earth while connected to the batteries while we were travelling or another time it could have been a fire that would have been hard to stop as you can't access this area quickly if at all in a hurry.

 

[pyro]

Wow. Bad design or what?

Replacement cables required (obviously), probably some heat shrink to protect against recurrence, also cable ties to hold them away, plus something to protect against sharp edges. As you say, a serious fire potential there

Your volts reading could be caused by resultant damage in ancillary equipment

 

[veevee]

Yes I've done all that Pyro and I thought this had happened because of no cable tie to stop vibration, but you can see from the photo below that the cable tie was in place but has burnt through, it was at the bottom of the box under the cables.

I thought without knowing why it should be that there was electrical power in something still connected that was giving the first reading, but taking a reading (without a single change to the set-up from the previous day and finding nearly a 3v increase threw me completely.

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[pyro]

Hmm. I am guessing here, as I am unfamiliar with just about most of the set up, but if there is a capacitor in anything connected to the circuit, then you could register residual voltage (that would decline as it slowly discharged through the internal resistance of the meter)??

Weird

 

[TheBig1]

there are capacitors in the charger itself, but thought you had isolated that

did you replace the wiring or just cut out the burnt area and rejoin and insulate?

to prevent it happening again you can buy a knock on edging to cover the sharp metal edge

 

[veevee]

In the respect of having switched the EBL battery switch off the charger was isolated. There was no 230v power in as it was physically disconnected and switched off internally. The two hab batteries were removed from the vehicle and the two lead sets in the battery box are not positioned within 300mm of each other.
The only power into the entire vehicle was and is the starter battery.

I cut out the burnt piece from each cable, reconnected with a large suitable size chocolate block which was clean. These cables are completely insulated now as are the starter battery charger cables too. I have strapped a piece of soft plastic to the underside of the support bar where most of the damage was done, the piece of plastic extends under the rail of the seat box too.
For the charger cables and others that were vulnerable I have used small bore neoprene hose to cover the threads of all the self-tapping screws that screw down and into the seat box, one of the charger cables and another set of cables was very close to the very sharp points of the self-tappers.

I tend to work on our camper at our French holiday home as we have unlimited space here, not all auto materials are easily available in rural France so I usually have to wait until we're back in Essex. Know the stuff you mean and you have reminded me to put it on the shopping list, thanks Big1

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[pyro]

In the respect of having switched the EBL battery switch off the charger was isolated. There was no 230v power in as it was physically disconnected and switched off internally. The two hab batteries were removed from the vehicle and the two lead sets in the battery box are not positioned within 300mm of each other.
The only power into the entire vehicle was and is the starter battery.

Perhaps just stating the obvious, but the big capacitors are on the output side (the 13.8v) of the charger to smooth the output, and most likely wouldn't be influenced by the presence of mains voltage on the input (mains) side.

Unless I have misread you, worth disconnecting the output side of the charger altogether, and then testing again, this would eliminate a capacitor in the charger.

 

[JeanLuc]

I have exactly the same set-up in my B630 Star-Line except that it is an EBL99. I had to remove the EBL early last year to return it to Schaudt for repair (the front panel on/off switch had failed). I too noticed some potential at the rear terminals although I disconnected the 50 amp fuses in the engine bay and next to the Hab batteries and also the 2 amp fuse next to the hab batteries before I did anything. I also pulled the 20 amp fuse in the engine bay (next to the 50 amp one) that supplies the fridge when moving. I have never found the 2 amp fuse that is supposed to be in the engine bay so could not pull that. The 2 amp fuses next to the hab and starter batteries are for a sensor cable and the D+ line respectively. In my case, I found that the D+ feed to the EBL was from a cable under the driver's seat that appeared to be a Mercedes fitting so perhaps the fuse is somewhere else in that line.
I still had no explanation for the residual voltage at the EBL rear terminals though and calls to a couple of Hymer dealers did not leave me any the wiser. Needless to say, I ensured the bare cable ends were all insulated whilst the EBL was removed from its location. Also, make sure you wrap the end of the screwdriver with tape before going near the terminal block on the EBL, in case you touch bare metal.

Nothing amiss happened to my set-up and I have never detected any drain from the starter battery (even before I had a solar panel fitted).

n.b. the EBL can deliver residual current after it is switched off, presumably from capacitors. Also, all though not related to your query, some of the 12V feeds out of the EBL are still live after the control panel master 12v switch is off. This is because the EBL contains two 12v feed relays - one is switched by the control panel and the other is switched off only by the front panel switch. The latter live feeds operate the Truma frost protection valve, the step, the Truma ex-eis lpg regulator heater (if fitted) and the door light. On an EBL99, positive pins 1 and 4 on block 5 are also live even when the control panel switch is off.

 

[veevee]

Thank you Pyro, and JeanLuc you are a hero

Thanks very much to all.

Currently altering the positioning of the 2 original batteries but not sure I am going to succeed. The original fitment of the two batteries facing each other with the terminals and more so the battery clamps only a few centimetres apart. As at each end of the batteries it is + facing - and the batteries are joined together by the cables, it looks like a disaster waiting to happen as terminal covers are difficult to fit due to the clamps and cables.
JeanLuc, are your batteries facing inwards too? And when you sent your EBL back for repair where did you send it, Germany?

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[JeanLuc]

Here is a picture of my previous batteries (Elecsol 110) - I now have 2 x 90 Ah Varta LFD90. As far as I can remember, the cable and terminal layout is the same (both + terminals to the left of the picture).
I returned the EBL to Schaudt after an email exchange with Udo Lang. It was cheaper than any repair cost that I have seen quoted in the UK, even allowing for shipping costs.

 

[XRN]

@veevee I will be checking my wiring after seeing the shorting damage to your cables, thanks for the info.

 

[veevee]

It wasn't intended to scare other owners but it's good to be aware that this type of situation can occur when any soft material sits on a metal edge or in this case rubs against a metal panel.
With any vehicle I always look around when doing something and of course with the amount of wiring in a MH there is more potential for damage.

It can also occur with other materials too, once found a water pipe about to burst as it had been hung over a metal lip, and of course with a vehicle that moves vibration is always going to occur to one degree or another and can damage soft materials rubbing against metal.

In the main our MH is great but I'm always looking at detail will eventually find a few things that should have had more care or better design, no company is perfect.

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[veevee]

A little progress today. Both batteries fitted in the same direction, ie side by side with the + terminal at the rear on both. This entailed re-routing the original battery cables, the final routing and layout only came about by trial and error, similar to JeanLuc's but at 90o to his. Much happier with this cable set-up now as the + cables are in conduit where required, there's a little finishing work to do including modifying the terminal covers to cover the battery posts.

Switched on the 12v system this evening and reset the capacity to 180A, the readings are normal for re-connection after everything was switched off. Can't start the charger yet as have to flick the switch on the EBL from Lead Gel to Lead Acid batteries, but to get at the switch the seat assembly has to come off again and it rained heavily here this afternoon.

Here's a photo of the re-routed cables with the new Varta LFD 90s. I have created different thickness ply boards to act as spacers for the gaps on the left, right and center of the batteries (the front one is already fitted), without this they could possibly move sideways when cornering, the metal strap across the top of the batteries is only making glancing contact and although will help going over a speed bump doesn't clamp the batteries down. The vent hoses and ply boards are yet to be fitted.

 

[JeanLuc]

Very neat job veevee. By the way, it looks as though the battery orientation may be the same as mine, assuming the left hand white wall is the outside wall of the Hymer. I cannot quite work out which viewpoint your picture is taken from. In my picture, the outside wall is at the top and the batteries run fore and aft.
On another point, I too carried out some insulation modification to the cables beneath the driver's seat when I first worked on the EBL area as I was concerned at possible chafing. There was no sign of damage but I wanted to prevent any future problem. Another interesting point, my handbrake is on the outside of the seat base in the well by the door but I see yours is on the inside. Perhaps that is a difference between a 316 and 416 chassis?

 

[berni109]

I remember reading (maybe on here) that with a bank of batteries the live should be on the first one and the earth on the last one.
Think there was some technical explanation but cant remember what it was.

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[veevee]

Yes, got that wrong re orientation, the batteries are in the same direction. It makes sense now that you must have L shaped seating? , we have a dinette. And yes again, it's LHD and the handbrake is on the inside of the seat box, I'll post a photo of the cab area once it's all cleared up so you can see any differences. At the moment it's full of stuff from working on these electrical jobs. But after I reset the EBL this morning I have 3 or 4 full days of 'real' work so it may be next weekend before you see it.

Thanks Philip

 

[veevee]

I remember reading (maybe on here) that with a bank of batteries the live should be on the first one and the earth on the last one.
Think there was some technical explanation but cant remember what it was.

You may be right berni109 and it will be as far as connections go.

The original idea was just wanted to identify which battery is which for the future rather than the connection sequence. At the point of numbering them the idea was to start under the window and work in, seemed logical to me at the time. The connection sequence wasn't known due to the battery leads having a fixed length and starting point and I had to try to separate the battery terminals from facing each other. With the different orientation (turned through 180o) of the outside (LH in the photo) battery the outgoing lead to the EBL wasn't long enough to reach the window battery.
When the 3rd battery is added the leads will start from the LH battery which will be positioned the right of battery No.2, confusing eh?

 

[johnandi]

Although I've never used them I've been told that A&N Caravan Services, based near Colwyn Bay, North Wales specialise in Electroblok repairs, but there is possibly a long waiting list. (http://www.aandncaravanservices.co.uk/)

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[JeanLuc]

Although I've never used them I've been told that A&N Caravan Services, based near Colwyn Bay, North Wales specialise in Electroblok repairs, but there is possibly a long waiting list. (http://www.aandncaravanservices.co.uk/)

They do and so do Apuljak engineering Apuljack Engineering - EBL Repairs

However, I think you may find it cheaper to send an EBL back to Schaudt in Germany. Obviously it will depend on what needs to be fixed, but as an example, in November 2015, mine needed a new front panel main switch and a new Block 1 where the fridge connection had burnt due to arcing. That plus relevant internal wiring and a full operational test cost me €68.46 including the return shipping. As I remember, the job took less than three weeks from despatch to return and most of that was transport time. In early 2016, one of the meters in my control panel failed (IT992 with two needle meters). Again I sent it back to Schaudt and the total cost from them was €69.62 including shipping and once again, the unit was with them for less than a week. They are very helpful (Udo Lang) and I have also had a lot of advice regarding how the EBL unit works, additional information on the wiring diagram and how the internal relays are switched, and the supply of extra MNL pins to make additional connections to the front panel. Before anyone says Schaudt units must be unreliable, don't forget mine are now 14 years old as the van left the Hymer factory in early 2003.

 

[johnandi]

They do and so do Apuljak engineering Apuljack Engineering - EBL Repairs

However, I think you may find it cheaper to send an EBL back to Schaudt in Germany. Obviously it will depend on what needs to be fixed, but as an example, in November 2015, mine needed a new front panel main switch and a new Block 1 where the fridge connection had burnt due to arcing. That plus relevant internal wiring and a full operational test cost me €68.46 including the return shipping. As I remember, the job took less than three weeks from despatch to return and most of that was transport time. In early 2016, one of the meters in my control panel failed (IT992 with two needle meters). Again I sent it back to Schaudt and the total cost from them was €69.62 including shipping and once again, the unit was with them for less than a week. They are very helpful (Udo Lang) and I have also had a lot of advice regarding how the EBL unit works, additional information on the wiring diagram and how the internal relays are switched, and the supply of extra MNL pins to make additional connections to the front panel. Before anyone says Schaudt units must be unreliable, don't forget mine are now 14 years old as the van left the Hymer factory in early 2003.

That's really useful information. Prices are excellent, particularly as shipping costs must form a reasonable proportion of the total!

 

[veevee]

OK, next step and possibly a very stupid question.

Wanting to get this endless saga just right I read the Schaudt manual for the DT 201 control panel in regards to resetting the control panel after new batteries (or even just full disconnection of same batteries), it quotes this.

After exchanging the living area battery, the nominal capacity must be reset


in the battery display. This must be carried out even when the capacities of


the new and old batteries are identical. This resets the control and display


panel to the “New battery value” for the max. usable capacity (80% of nominal


capacity).

If you have a 100A battery, do you set it at 100A or do you set it to 80A? The last sentence is ambiguous and suggests either value to me. In the past I have always entered the 'nominal' value as being what is theoretically available but in practice knowing it is a value less than that advertised.

Yesterday afternoon I entered 180A as the value, on completion a figure I had seen before a half of that appeared on the screen, 90A. This happened a few times before but would always reset to the full amount eventually.

Yesterday afternoon during the first hour of reconnection the value shown while the new batteries are being charged reduced from 90A to 3A and there it sits. The volts are ok at 14.4v and 13.7/8v when on float. I have written to Udo Lang about this amperage problem and wait for a reply, but just getting back to basics, what value do you enter as the 'nominal' value when fitting or re-starting hab batteries?

Thanks

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