# baffled by battery charging problems on Knaus



## bravocharlie (Jul 15, 2006)

I have a 2006 Knaus MH with 2x100ah leisure batteries, an engine starting battery and an 85 watt solar panel. I have only used the 'van on hook up so far, yet the on -board battery state indicators have shown the leisure batteries to be well depleted sometimes and full at others. 
The motorhome was recently in storage (outside) yet after 8 weeks or so the leisure batteries were shown to be almost flat. This has happened twice. The engine battery was also shown as being slightly discharged although the engine started ok. It is now on hook up and the batteries are back up to full.
I bought a mutimeter and the reading today after disconnecting from hook up for 4 hours was 13.3v. On reconnecting the hook-up it still showed the same reading. I am not well versed on electrics and have never used a mutimeter before so I would appreciate some advice on the following:

Why, with an 85W solar panel installed did the batteries go flat even in winter? Everything was switched off except the alarm.

Does the above suggest a wiring problem causing some sort of battery drain, and if so, can I check this with the multimeter? How do I do this?

I want to be able to use the MH without hook up which is why I had the panel installed. As I am new to this exciting new world of motorhoming I would be grateful for any ideas or thoughts on the subject.


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## eddied (May 9, 2005)

*Battery charging problems*

 
Hi there, I'm along way from being any expert on this, and somebody will no doubt give you the right answers shortly. However, experience has taught me that sometimes when you say 'evrything has been switched off' there can still be some little gizmo somewhere slowly draining amps. e.g in my own case, a TV aerial booster, out of sight and therefore out of mind, in a wardrobe.
saluti,
eddied


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## teensvan (May 9, 2005)

Hi bravocharlie.

During the winter months batteries can loose up to 2% of there charge per week which is quite common, when very damp. I do not know much about solar panels, but a panel of 85 watt should easily keep the batteries topped up even at this time of year. You could take a voltage check on your leisure batteries about 13.3 volts , and then disconnect them for one week then recheck voltage. Should not be much lower than 13.0 volts. I expect someone else will be along soon to explain in more detail.

steve & ann ------ teensvan.


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## artona (Jan 19, 2006)

Hi Steve and Ann

Just sent you a pm


stew


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## bravocharlie (Jul 15, 2006)

Thanks for your replies.
Eddied, I have checked to see if everything is off and apart from the alarm systems it looks ok.
Steve and Anne, I have taken up your suggestion and unhooked the mains power. Will check it in a few days. Thanks for that.
Any other suggestions welcome.


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## wakk44 (Jun 15, 2006)

hi bravocharlie,

I also have an 85watt solar panel but with 3 leisure batteries on board.The solar panel even at this time of year is producing 0.5A/H to the batteries and is keeping them fully charged.They tend to read 80% state of charge on the regulator early morning,but then charge up fully after a couple of hours.

Your 85 watt solar panel should do the same and keep your batteries conditioned all year round,I suspect you may have a problem with the solar panel not charging correctly.What charging current is showing on the regulator,recently mine has been 0.3A/H-0.5A/H in cloudy weather and then around 1A/H when sunny,this will increase to approx 5A/H in the summer.

Also your leisure batteries efficiency may have been affected after going flat on 2 occasions,they are recommended not to go below 50%.Try checking the in-line fuse from the solar panel which should be near the positive terminal of the leisure battery.If that is ok then try putting your meter on the solar panel terminals at the regulator(hopefully when the sun comes out)to check its output.

Steve and Sharon


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## bravocharlie (Jul 15, 2006)

Hi Steve and Sharon,

Thanks a lot for your suggestions which make a lot of sense. 

Unfortunately I am very new to this game and although I understand your recommendations I have a couple of problems in following them. For example I don't know where the regulator for the solar panel is situated or even what it looks like. I can find nothing which indicates the state of charge except two rows of LEDs, one for the engine battery and one for the leisure batteries. These do not seem to be very accurate. Also there does not appear to be any means of indicating the charging current from the solar panel.

I think the panel is providing some charging effect as I have been monitoring the battery state with my multimeter since disconnecting from the mains. For example, it increased from 12.9v yesterday evening to 13.2v during daylight (sunny) today. 3 hours after dark it again read 12.9v. Since there was no other source of charging I am assuming the panel was doing its work but, of course I can't tell how efficiently. 

What I can't understand is why during the period when the MH was stored away from my home with no hook up available, the panel allowed the batteries to discharge. I don't think they went completely flat (I didn't have a multimeter at the time) but the LEDs showed they were well down.

I intend to keep monitoring the state of charge but any other suggestions would be most welcome.


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## wakk44 (Jun 15, 2006)

hi again,

it sounds like your solar panel is working ok if the battery voltage goes to 13.2 during the day and then decreases slightly overnight,mine is more or less the same.What I can't understand is how the leisure batteries went flat whilst the m/home was in storage.An 85 watt solar panel should easily keep the batteries topped up even in winter.

Are you sure all the 12 volt appliances were switched off whilst in storage,and was it stored under cover i.e.no light getting to the solar panel?

If you can find the regulator it may give you the solar panel output,battery voltage,SOC,and charging current going into the batteries on a digital display,on mine(steca)you can scroll down for the different readings,depends what type of regulator it is.

The regulator is normally positioned above the habitation door somewhere or perhaps in a wardrobe or locker.They are normally post-factory fitted,try looking for some info amongst your instruction manuals,or getting in touch with the previous owner who may be able to help.

Steve and Sharon


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## bravocharlie (Jul 15, 2006)

Hi Steve and Anne,
Thanks again for your help. The answers to your questions are:
I am sure that all 12v appliances were switched off during storage.I have basically moved the MH from a remote storage facility with no mains power to my home and haven't switched any apliances on or off in the process, so having checked again, I can safely say they were all off.
It was stored in the open so the panel was fully exposed to the light.
I have found a single page leaflet in the documentation which shows the wiring for a solar regulator but has no apparent facility for readings on it. I don't know where this is installed but I have found a small square box next to the battery charger which may be it. If so, there are no dials or indicators on it.
I am beginning to think that the panel is only partly charging or else there is a drain on the system somewhere. I have been carefully monitoring the voltage at the leisure batteries and it seems to be dropping slightly. Since yesterday it has dropped from 13.2v to 12.95v during daylight and from 12.88v to 12.82v after dark.
I bought the motorhome new last year so it is still under warranty but getting the dealer to fix it will involve a round trip of 3 days and 500 miles so I would obviously prefer to find a solution myself. I intend to monitor it for a few more days to see what happens.
Thanks again,
Brian


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## wakk44 (Jun 15, 2006)

hi Brian,

the leisure batteries do tend to read slightly less in the morning so that is normal,however the voltage should increase during the day when the solar panel is working.

My best guess is that either your solar panel or regulator is faulty,the best way to test them is to connect an ammeter in series between the regulator and the leisure batteries,this will check the output from the solar panel and also prove the regulator is functioning correctly.

It's a pity the dealer is so far away as I think you need specialist advice,do you know anyone locally that can check it out and would your dealer pick up the bill?As it's still under warranty it might be a good idea to give them a ring and sort something out,let us know how you go on.

Steve and Sharon


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## bravocharlie (Jul 15, 2006)

Hi Steve and Sharon,
Your suggestion is a good one. I think I will monitor the voltage drop over the next few days and then ring the dealer to see if they will accommodate me in getting some local help.
Thanks again for all your input. I'll let you know how I get on.
Brian


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## bravocharlie (Jul 15, 2006)

Hi Steve and Sharon,

I've finally got the problem sorted by the dealer (Lowdhams of Huddersfield) who was extremely helpful and efficient. The battery charger was faulty and has been replaced under warranty. The solar panel seems to be charging ok and I think that the faulty charger may have been draining the battery. Got a couple of other minor things sorted at the same time so the journey was well worthwhile.

Thanks a lot for your help. All is now well.

Best wishes,
Brian


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## wakk44 (Jun 15, 2006)

hi Brian,

pleased you got it fixed and received good service from Lowdhams,how about putting an entry in the company reports forum?

We all like to know on here who the good companies are.

Steve


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## bravocharlie (Jul 15, 2006)

Done.
Thanks again,
Brian


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