Truma Solar Dual Battery Charger SDC 10/20 - Not charging: New Coachman VIP 520

[thensum]

Hi All,

 

I was wondering if someone could help me?  We picked up our new 2021 Coachman VIP 520 caravan on Saturday 10th July, from our dealership Lee Davey Caravans, near Maidstone.  We had the optional extra solar dual battery charger fitted by the dealer, however I am not sure if it is working correctly.  Some of the functions are working but the main function of charging the leisure battery isn't.  I have tried to explain below some of the background and the current situation:

 

- Brand new Platinum AGM 100amp battery purchased from the dealer’s shop and installed at handover on 10.07.2021.

- We ran the mains charger on Saturday afternoon and Saturday night and the leisure battery level was at 13.8v.

- I turned off the mains supply to the caravan early Sunday morning to see if the solar panel would start charging from the solar panel unit, but currently it doesn’t look like anything is charging as the battery level has started to drop.

- Battery level has dropped to 12.8v now on the master panel and is showing the letter L for low.

 

I have detailed below what I can currently see functioning on the unit:

 

Device Elements (H1 – H5):

 

H1 LED Function display battery 1 (supply battery)

H2 LED Function  display battery 2 (starter battery)

- During handover neither H1 nor H2 LED function display had lights on.  We only have 1 battery installed as it is a touring caravan, so probably only H1 that would function.

- Under normal operating conditions should the H1 function LED display have a light whether it is charging or not?

- Just to confirm H1 nor H2 LED function display have not lit up at anytime.

 

H3 LED - Battery Type:

- H3 LED function display is set at 2 which the dealer set and I believe is correct for the AGM battery we have installed when checking the instruction manual, this does lit up in the display.

 

H4 LED - Charging current distribution:

- H4 LED charging current distribution is showing the number 9 which is 90% according to the instruction manual.

 

H5 LED - PWM charging frequency:

- H5 LED PWM charging frequency is showing 0 which looking in the instructions means the PWM charging frequency is 25Hz (pre-setting).  Is this the correct setting? Other settings include:

1 - 50 Hz

2 - 100 Hz

 

I have also sent an email to our dealer earlier this morning, Lee Davey Caravans to see if they can advise but I am currently awaiting a reply from them.

 

Thanks,

 

thensum

[Lost in the wilderness]

You need to check some voltages at the solar controller. If you don’t have a multimeter, suggest you invest in one. 
First, with good daylight, measure the voltage across the two solar panel terminals. You would expect to see over 15v. Then check the voltage across the two battery 1 terminals. You should see between 12.7 and 14.5v. 
If the voltage is low on battery 1 terminals, locate and check the solar fuse - between the solar controller and the battery 

[thensum]

21 minutes ago, Lost in the wilderness said:

You need to check some voltages at the solar controller. If you don’t have a multimeter, suggest you invest in one. 
First, with good daylight, measure the voltage across the two solar panel terminals. You would expect to see over 15v. Then check the voltage across the two battery 1 terminals. You should see between 12.7 and 14.5v. 
If the voltage is low on battery 1 terminals, locate and check the solar fuse - between the solar controller and the battery 

Thanks for the response.  I have contacted the dealer again but sent the email direct to their General Manager/owner who we negotiated the sale with.  I too wondered if it was a fuse issue may be?  I'll also invest in a multimeter, any recommendations?  Amazon may be?

[Alan Stanley]

First off your solar will only work when needed.  Your voltage reading of 13.8 is the volts as provided to the battery by the battery charger.  This is correct.  If you disconnect the battery from any form of charge it will drop back quite rapidly to about 12.7/8 volts.  this again is correct that is the reading that you would expect from a fully charged battery.

 

I do not understand your reading of 12.8 v on your control panel being referred to as 'Low'. 12.8 volts is a fully charged battery, certainly not low.  Caravan control panels in my experience are notoriously inaccurate.  To get a proper reading of the battery you need to measure it at the terminals with everything switched off with a multi meter.

 

Setting 2 is correct for AGM battery.  The controller will automatically send all the solar to the one battery fitted when only one is fitted.

 

From memory when the Led flashes longer intervals the battery is being charged.  Solid light is fully charged,  Flashes a very short intervals then the battery is not being charged for some reason like a faulty battery.

 

No light at all during during daylight strong enough to generate any power would get me looking to see why the solar charger thinks no battery is connected.  Had it on a swift van where the connector block behind a  panel was not pushed home.  This was after a dealer replaced two controllers as faulty, they were not.  Also there is probably a fuse somewhere (well there should be)

 

I hate these control boxes as they tell you not very much, and are confusing,  far far superior stuff is on the market.  

 

Get a multi meter and measure the volts at the two Solar input terminals (in the middle if I remember). No need to disconnect just use the probes on the screw heads.  (while you are at it check the wires are in and screws nicely tight).  If that gives a reading of something above 12 volts usually about 17 -18 v then the panel is providing power.  Not conclusive but a simple way to check that it is reaching your battery is to cover the solar panel with a cloth or cardboard and measure the battery volts at the terminals.  Then get someone to expose the solar panel and the volts meter should register an increase at the battery terminal. ( During the bright part of there day obviously.)

 

Amazon or BQ for a multimeter,  Absolute necessity for tracing power faults.

 

 

 

[thensum]

Just looked at the trouble shooting guide in the instructions manual again and if the H1 or H2 LED which shows the status of the battery does not shine then the cause is battery not connected or over-voltage.  Obviously it is connected as the lights, etc. are working and it has been on mains charge as above.

 

Dealer has now come back to me and they are looking into the matter.  I await their call, feedback.

 

thensum

[Alan Stanley]

Not sure of the truma regulator as I do not have one to hand but, -  Many regulators need connecting in a certain order to start working.  They need to know whether they are working on 12 v or 24 v and I think the truma has this volts range.  If so then you need to disconnect (one wire) or cover the solar panel.  Then disconnect the caravan battery and unplug from mains. Connect the battery up again and that will tell the solar it is a 12 v system.  Then reconnect or uncover the solar.  All this depends on the wiring and fuses working of course.  

[Guest CliveB]

This link gives detailed instructions (OEM not Truma) for the controller if it is the same as mine in my Bailey (same controller without Truma sticker).

https://www.photonicuniverse.com/upload/file/Manuals/DB1024/DB1024_and_DB2024_instruction_manual_v2_15_June_2015.pdf

DB1024_and_DB2024_instruction_manual_v2_15_June_2015.pdf

Edited July 12, 2021 by CliveB

[tytonline]

The L on the control panel refers to leisure battery not low battery. I was told the same software is used in motor homes where it can show a V for the vehicles battery and a L for the leisure battery. 

[Mickyjb]

You need to have a look for the inline fuse as per the Solar Panel section of the handbook 'If the battery is removed you must also remove the in-line fuse for the solar panel. This is located in the fuse holder situated between the regulator and the battery'.

It probably won't have been put in place by the dealer, ours was taped to the fuse holder.

[8ftWanderer]

8 minutes ago, Mickyjb said:

It probably won't have been put in place by the dealer, ours was taped to the fuse holder.

There is a very good chance this is the issue.

 

The fuse on mine was taped to the cable when we picked it up. The dealer removed it and inserted it as I asked what it was.

 

The following day, the same as you no solar charging.

 

I checked the fuse and the dealer had pushed it in but the wrong way round. I removed the fuse, inserted it correctly and all was good.

[thensum]

1 hour ago, tytonline said:

The L on the control panel refers to leisure battery not low battery. I was told the same software is used in motor homes where it can show a V for the vehicles battery and a L for the leisure battery. 

Thank you for the clarification still getting used to the different control panel in the Coachman after having a Swift previously.  That makes perfect sense. 

53 minutes ago, Mickyjb said:

You need to have a look for the inline fuse as per the Solar Panel section of the handbook 'If the battery is removed you must also remove the in-line fuse for the solar panel. This is located in the fuse holder situated between the regulator and the battery'.

It probably won't have been put in place by the dealer, ours was taped to the fuse holder.

The dealer has asked me to check the inline fuse, having looked at the 27 page handbook the pgs 1-15 are in English but only seems to cover operating instructions and no mention of where to look for the inline fuse?  The remainder of the pages are in foreign languages covering the same operating instructions.

 

I have looked at where the black cable from the back of the battery box feeds under the bed locker and can see a 'rubberised' casing on this black cable which them seems to feed into a large black covered mound siting behind the main circuit breaker.  Is this ''inline'' black rubberised box where the main fuse for the solar panel is located?  It's now when you need to share photos.

 

The caravan is brand new and had no leisure battery installed when we collected it on Sat morning.  We purchased a new Platinum AGM battery from the dealer's shop on Sat morning and then installed it as part of the handover.  Are you then saying that after the battery is connected then they should have installed the main inline fuse for the solar panel?  I'll go and have another mooch around but I cannot see anything taped anywhere, but chances are it might be installed in correctly?

[Mickyjb]

The 'solar fuse' is in the positive feed cable from the solar-controller to the battery. The fuse should only be in-place when there's a battery fitted so, the dealer should have fitted it once the battery was fitted - as said mine wasn't but, it was fairly obvious once I looked.

The handbook I quoted is the one from Coachman for the caravan as a whole. My caravan is in storage so can't take and post a photo at present.

[thensum]

10 hours ago, Mickyjb said:

The 'solar fuse' is in the positive feed cable from the solar-controller to the battery. The fuse should only be in-place when there's a battery fitted so, the dealer should have fitted it once the battery was fitted - as said mine wasn't but, it was fairly obvious once I looked.

The handbook I quoted is the one from Coachman for the caravan as a whole. My caravan is in storage so can't take and post a photo at present.

OK thank you I'll read the main Coachman manual and also see what the dealer says today as the Service dept have been in contact with advice and items to check.  I think it is something minor.

[charlieboy2608]

Multi meter from screwfix at a good price and does the basics :-)

 

LAP MAS830B Digital Multimeter 600V (75337)

[Guest CliveB]

Just to add one more possibility which happened on my new Bailey.

The solar charging failed at the connection between the solar panel output cable and the input to the controller.  This is outside under the panel.

Push connections cleaned and remade.

Diagnosed initially because close to 0v detected at the input to the controller (checked by removing the input cable).

The first place to start when you have the multimeter?

[badgersky]

I'm also having issues with my 4 Yr old truma 100w  solar panel charging, battery not holding the charge H1 led flashing slightly erratic, check several things pushed all connections swore several times then in desperation took the fuse out between the charger and the battery (is in the cupboard just below the charging unit) checked it was OK which it was,  and then refitted it, bingo led solid light voltage steadly increasing, so was it a small amount of corrosion, had the fuse been dislodged but I had pushed it home at the start of my investigation so not sure but may ? have saved £100+ for a new battery