Auxiliary battery dead? (1 Viewer)

[Lenny HB]

I think your van has a single stage charger that only charges up to 13.8v so the battery never gets a full charge like the modern multi stage chargers are able to deliver.
With that type of charger not unusual for the battery to only Last 2 or 3 years.

 

[MarionK]

It says it's a three stage charger. . . whatever that means

 

[Cush]

I found this which may help to show if the fault lies with the charger…

”On EHU any position everything works.
Aux position everything works - leisure battery gets charged.
Center only - everything works off mains.
Main is engine battery, everything works on EHU but engine battery gets charged.
Good tip select this position for last 24 hours of your stay so engine battery is topped up.”

hope it helps

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[Cush]

Using my likely flawed logic I would suspect that.

It shows that your aux battery is goosed. On EHU with the aux setting selected you will be running of EHU straight through your batteries but they won’t be charging. Everything willl appear to work but actually be using 240 supply. When you turn the EHU off then there is literally nothing there, hence no lights.
on the bright side, your starter battery may be in good nick?

A bit more info on why it seems to be dead:
When the panel by the camper door has the switch set to MAIN, AFAICT, everything works, and the BATT light shows green, with or without the charger being on, and with or without connection to external 240v supply.
With the charger off, and the switch set to AUX, (or half way) all the lights go out, (unless connected to the mains and the charger is on, in which case everything "seems" fine.)

 

[autorouter]

Could it be the battery fuse that someone mentioned earlier is blown?

There should be a fuse near the leisure battery, worth checking that I think. If it's OK, check that you are getting the battery voltage at the fuse terminal, that will confirm the wire between the battery and fuse is OK.

If that's OK, check the power input to that panel. One thing worth checking is whether there is battery voltage at that AUX fuse. Remove the fuse and probe the fuse terminals, both the back and the front terminals.

It says it's a three stage charger. . . whatever that means

The three stages are called bulk, absorption and float.
Bulk: a constant 13A current. The voltage slowly rises until it reaches the absorption voltage. It's then about 80% charged and switches to the absorption stage.
Absorption: Keeps constant absorption voltage, the amps gradually reduces from 13A to a predetermined limit, probably about 1.3A. It's then 100% charged, and switches to the float stage.
Float: the charger outputs a voltage that is just enough to compensate for the self-discharge without overcharging. It can stay on the float stage indefinitely.

I can't read the absorption and float voltages on the charger label, but they will be about 14.5V and 13.5V.

 

[MarionK]

It's the battery fuse! I never heard of such a thing until your post earlier in this thread autorouter, thanks again
What is it for actually? Protecting the battery? From ?
Also, it's a very pale peach colour, so I'm not sure if the replacement should be brown, tan, or what. I can't find any mention of it in the manual. :?

eta: On the panel, I can't get to both fuse terminals at the same time. The probes have an awkward flange on them

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[autorouter]

What is it for actually? Protecting the battery? From ?

Any wire connected to a battery needs to have a fuse, to protect against wiring faults such as short circuit to the metal bodywork. Without a fuse, the wire heats up and can easily cause a fire. With a fuse, the fuse blows and the excessive amps stops. The fuse should be as near the battery as possible.

The fuse should be labelled with its amp value - if it's a peach colour it may be 40A. But it should have a label on it somewhere.

 

[MarionK]

It's '5'. :S I presume that's enough to run the circuitry, but anything more demanding will have to be gas or only while on ehu.
Not a big deal tbh, but I'm wondering what blew the fuse. Would having the fridge set to run on electricity draw too much? Fingers crossed that's what did it because otherwise, there must be a 'short' somewhere.

 

[autorouter]

I'm sure that's not the main fuse from the leisure battery, 5A is just not enough. The mains charger is 13A for a start. 30A is a common value, on mine it's 50A. It should be on a fairly thick wire. Wire is sized by cross-sectional area (CSA) in square millimetres. 'Thin' wire in a MH is about 1.5mm2, power wires are likely to be 6mm2 or 10mm2, which look a lot thicker.

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[MarionK]

The fuses on the panel are all 10A, 3x10 is 30, so not unreasonable to expect battery (and wiring) to tolerate 30A?
Maybe a previous owner put a lower value fuse in in a pinch, and never changed it for the proper value one?

 

[Spriddler]

View attachment 583578

The fuses on the panel are all 10A, 3x10 is 30, so not unreasonable to expect battery (and wiring) to tolerate 30A?

Yes, in theory, but the wiring and fuses will never see that current as the 5 Amp fuse at the battery will blow as soon as the current exceeds 5 Amps.

Maybe a previous owner put a lower value fuse in in a pinch, and never changed it for the proper value one?

If the fuse to which you're referring is the main leisure battery supply then I'd say you're right. I.e. a PO has fitted a 5 Amp fuse which is insufficient to feed the hab electrics. I'd say it must be at least a 30 Amp fuse and the red wire in your photo looks to be well capable of carrying 30 Amps or more.

 

[MarionK]

Spriddler I do realise that the 5A fuse blew long before the panel got even 1x10A, the thing is, I don't want to start a fire because I put in a higher rated fuse. ;P

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[Spriddler]

Indeed so, but IF that 5 amp fuse is the main supply to the panel it's rated way too low because just one of the fuses at the panel will operate up to 10 amps. I'm surprised that the 5 amp fuse didn't blow sooner. Is the m/h new to you?
The red cable in your pic (which will be feeding only the panel) looks to be easily capable of handling 30 amps.
Any faulty 12v item or wiring that's downstream of the panel (lights, fridge, water pump etc) which might cause a fire will blow its 10 Amp fuse at the panel.

 

[MarionK]

Yes, that is my reasoning too.
Yes the mh is new to me, and the fuse must have blown sometime between me viewing the van and my first post on here, probably when I was playing around with the various switches.
I'm off out to get some fuses now Thanks everyone for your help.

 

[Lenny HB]

View attachment 583578

The fuses on the panel are all 10A, 3x10 is 30, so not unreasonable to expect battery (and wiring) to tolerate 30A?
Maybe a previous owner put a lower value fuse in in a pinch, and never changed it for the proper value one?

That looks like 10 mm sq cable which is rated at 70 amps. Because of the long cable runs you have to use much heavier cables (higher current rating) than the circuit will draw to keep the volt drop to a minimum.

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[Spriddler]

Yes the mh is new to me, and the fuse must have blown sometime between me viewing the van and my first post on here, probably when I was playing around with the various switches.
I'm off out to get some fuses now Thanks everyone for your help.

Yep, I couldn't see how the 5 amp fuse would have lasted any time at all.
I guess you don't you have a manual showing the fuse ratings? Deleted. I see from an earlier post that it's not mentioned in the manual.
Make sure that the 30, 40, or 50 amp fuse (if that's what you will be getting) will fit the fuse holder - take the blown 5 amp one with you.

 

[MarionK]

30A fitted now, and the lights are working. Panel shows AUX battery as high.
I'll check out the charger again, when I have time. Just in case, although something has definitely charged the battery at some point, it's possible that it only charges from the alternator, and it has merely kept it's charge?

What is the brown wire in the photo for? (Also connected to the positive terminal.)

Incidentally as I was picking out the 30A fuses, I noticed that the 40A fuses are a similar colour to the 5A, just darker . . .
And it's really annoying me that it's not in the manual.

 

[Spriddler]

Well done.
Incidentally I've found complete wiring diagrams for various years of the Cheyenne here:

Link Removed

I don't know what year Cheyenne you have and I know nothing about the Cheyenne but I notice it shows a 20 Amp fuse for the leisure battery for the 2006 model. Don't be alarmed but next time you're out maybe get a couple (one as a spare) of 20 Amp fuses and fit one instead of the 30. Other better informed than me ref the Cheyenne may know that the 30 will be fine and may be specified for later year models. The fuse is there only to protect the piece of red cable which runs from the leisure battery to the panel and the cable in your photo looks well able to handle 30 Amps. All the wiring 'going out' from the panel is protected by the several 10 Amp fuses.
Here's a snip that I've copied from the wiring diagram...........

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[autorouter]

What is the brown wire in the photo for? (Also connected to the positive terminal.)

Not wishing to open another can of worms, but is there a fuse on that brown wire, and if so what value? It's hard to tell from the photo, but it looks a bit thinner than the red wire.

The diagram in Spriddler's post shows two relays in the top left. The relay on the right is the split charge relay, that connects the starter and leisure batteries when the engine is running and the alternator is charging.

The relay on the left is the fridge 12V element power. It is only ever connected to the fridge when the engine is running, so the fridge is only ever powered by the alternator, and can't drain the starter or leisure batteries.

In the diagram, the blue wire labelled 'Alternator Field Circuit' switches the relays on and off. It is usually called the D+ signal, and is the same one that switches off the red alternator warning light when the engine is running.

 

[Prop]

I totally flattened a leisure battery and thought it was knackered but I bought a CTEC battery charger and reconditioned the battery (Other battery chargers do this as well) and got another couple of years out of it.

 

[Lenny HB]

I totally flattened a leisure battery and thought it was knackered but I bought a CTEC battery charger and reconditioned the battery (Other battery chargers do this as well) and got another couple of years out of it.

But it would have had a much reduced capacity, not worth the bother for the price of a battery.

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[Shelly1973]

Hi, just to say massive thank you for all these comments they are helping me as well...newbie MH Fiat Hymer 1993 x Shelly

 

[Scout]

Well done.
Incidentally I've found complete wiring diagrams for various years of the Cheyenne here:

Link Removed

I don't know what year Cheyenne you have and I know nothing about the Cheyenne but I notice it shows a 20 Amp fuse for the leisure battery for the 2006 model. Don't be alarmed but next time you're out maybe get a couple (one as a spare) of 20 Amp fuses and fit one instead of the 30. Other better informed than me ref the Cheyenne may know that the 30 will be fine and may be specified for later year models. The fuse is there only to protect the piece of red cable which runs from the leisure battery to the panel and the cable in your photo looks well able to handle 30 Amps. All the wiring 'going out' from the panel is protected by the several 10 Amp fuses.
Here's a snip that I've copied from the wiring diagram...........

View attachment 583765

having had two autotrails in the past 2005 & 2011 year models in both cases the batter fuse was 20amp .if in doubt look here

Technical Support | Sargent Electrical

Technical support information. If you require any further information you may contact our technical support specialists who will be more than happy to help you.

sargentltd.co.uk

 

[KimSteve]

The question isn't so much, "Is it dead?" as, "Why is it dead?"
I thought I had it on charge for the last 24hours, but it seems I had the charger switched off >.< so there's a faint glimmer of hope still but only faint.

I could really do with an idiot's guide to camper electrics . . .
Don't they charge up while the engine is running? Does the charger need to be on or off while driving?

I put Ctek charger leads on both van and leisure batteries, Easy to charge and they also condition the batteries. Took the leisure from dead flat to healthy, worth the £80 for the charger and additional leads.

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[weemalkie]

Just to add my twopence worth. I also had the same problem with a brand new battery. Bought the battery an Exide ES900 80Ah. Charged it up. and left the van with as far as I was aware nothing live. The 12V cut off on the EBL119 was in the On position but the control panel for water pump etc was OFF. No lights on .
Initial voltage 13.4V. After a couple of weeks voltage had dropped to 10.7V. !! Turns out that even with everything off the electronics are taking a charge and the frost protection valve is still active. So one wrecked battery which hadn't done any work. Lesson learned. Now about to install a battery monitor, buy new batteries and disconnect completely when going to be off line for any length of time. Recharge when voltage drops to around 12.8v.

 

[MarionK]

Not wishing to open another can of worms, but is there a fuse on that brown wire, and if so what value? It's hard to tell from the photo, but it looks a bit thinner than the red wire.

The diagram in Spriddler's post shows two relays in the top left. The relay on the right is the split charge relay, that connects the starter and leisure batteries when the engine is running and the alternator is charging.

The relay on the left is the fridge 12V element power. It is only ever connected to the fridge when the engine is running, so the fridge is only ever powered by the alternator, and can't drain the starter or leisure batteries.

In the diagram, the blue wire labelled 'Alternator Field Circuit' switches the relays on and off. It is usually called the D+ signal, and is the same one that switches off the red alternator warning light when the engine is running.

I already opened that can I like to keep a check on them. ;P
And no, no fuse that I can see, maybe at the other end? Wherever that might be? It is a bit thinner. Could it be for charging the battery?

I've downloaded the oldest schematic, but the panel and charger don't look anything like mine . . .but there is a brown wire connected to the live terminal of the vehicle battery. :S I need to print it off and get busy with the coloured crayons to even begin to make sense of it tho.

I totally flattened a leisure battery and thought it was knackered but I bought a CTEC battery charger and reconditioned the battery (Other battery chargers do this as well) and got another couple of years out of it.

I've thought about getting one but the choice is bewildering, so I'm opting for good maintenance, at least for now.

 

[Nedge68]

That looks like 10 mm sq cable which is rated at 70 amps. Because of the long cable runs you have to use much heavier cables (higher current rating) than the circuit will draw to keep the volt drop to a minimum.

Hate to disagree with you Lenny, but that looks like a 6.3mm spade connector with some 2.5 possibly 4mm cable which are rated at 30 and 40 amps (connectors only rated at 15-20A) Perhaps that explains the 20A fuse that is shown in the schematic by Spridder, unfortunately they don’t show the conductor c.s.a.

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