Finding flat battery problem.

[coach2000]

Hello all. I have a problem with both my van and habitation batteries going flat within a couple of weeks whilst not being used. They are alll newish and hold their correct full charge when disconnected.

 

I need to start to check for an excessive drain on the electrics with the ignition and control panels off. Can anyone tell me if you can get an output at the battery lugs from the solar panel when the batteries are disconnected or do they need a power supply to the regulator. I am trying to check the solar panel charging before I move onto checking each circuit.

 

Any help would be appreciated before my next trip.

 

Clive

[Ocsid]

I would be using this sort of device that plugs into each of the system's fuses [the removed fuse being put into its probe so the circuit is working and the current visible]

 

Today being the last day its sold at this reduced price by Maplin.

 

https://tinyurl.com/y7h24fvr

 

Or buy from these suppliers at a good price anytime:

 

http://cpc.farnell.com/tenma/ten01046/current-tester-automotive-std/dp/IN04874

 

Its a bit fiddly but very effective at sorting out these type of issues. Invaluable IMO for any tool kit for those doing the simplist of DIY on 12 volt car, motorhome or caravan systems

 

First just check the fuse used in your van is the standard blade type, if it is the "mini" blade size that version of this tester is also available from both these suppliers just needs searching out.

[Alanb]

The Fiat Ducato 2.8 JTD uses mini blade fuses, and there is a highh probability that the habitation electrics will use "Standard" blade fuses.

 

Given the expense of buying two testers I would consider going a bit further and buying a clip on DC ammeter, which could also have multimeter capabilities.

 

A current of just 0.2A will completely discharge the 100 Ahr starter battery in just 3 weeks.

 

Alan

[aandncaravan]

"Can anyone tell me if you can get an output at the battery lugs from the solar panel when the batteries are disconnected or do they need a power supply to the regulator. I am trying to check the solar panel charging before I move onto checking each circuit".

 

 

You should see the Solar regulator voltage at the Starter/Habitation battery clamps whether the battery is 'in circuit' or not. However, bear in mind that in December you will be lucky to see more than about 4Ah a day charge as the Sun is so low in the sky and the Solar day only runs from about 10:00 until 14:30

 

Also bear in mind a Static vehicle with the Alarm set can take the Starter battery down very low in 4 weeks.

If the Solar solution includes a Battery Master, then the Battery Master will suck the life out of the habitation batteries as well.

 

 

Are you sure your batteries are as good as you think, because Solar charging can degrade a battery quite quickly?

If you disconnect them they should hold the same voltage for around 5 weeks. Any voltage drop of even 0.2v isn't a good sign. What batteries do you have, make, size, technology, etc.

 

 

This time of year, right into February, we usually get quite a few calls like yours where the Solar power is no longer able to harvest enough energy to keep failing batteries charged up.

People forget just how little Solar power is generated in mid Winter.

 

I think you are doing the right thing starting at the Solar solution, but don't assume that 'young' batteries will be ok, we are seeing quite a few 'budget batteries' not much more than a year old that have been on a permanent Solar charge and suffered.

 

See our Solar Power webpages to check how good your install is : http://www.aandncaravanservices.co.uk/solar-power.php

 

 

 

 

 

 

 

 

 

 

[coach2000]

Ocsid: I will be collecting a fuse a tester from Maplins tomorrow thanks.

 

Alanb: I already have a clip on Ammeter but not tried it on D.C. it is not digital.

 

aandncaravan: there was a current of 0.3 amp showing on the panel with the batteries connected. Without the panel is not displaying. I am sure that I rad somewhere that you need a supply voltage to activate the regulator. It is a Sunworks make. I will try to contact their technical dept. tomorrow.

 

I do not set the alarm or have a battery master

 

The batteries are 2 years old (time flies) Varta 75 amp Dual purpose.

 

The engine battery Hankook 80amp Power 1 year old

 

Thanks.

 

 

[dipsticks]

These things are handy for making your own test interface if you already have a multimeter, and avilable in standard and mini fuse sizes.

 

link for mini fuse size

 

http://www.ebay.co.uk/itm/Add-A-Circuit-Piggy-Back-Fuse-Tap-Mini-Blade-Fuse-Holder-ATM-ATP-12V/281913202584?hash=item41a3561798:g:r2YAAOSwd4tT8HIu

 

Especially for Cheapskates !!!

[Alanb]

Then by inference I must be a cheapskate!

 

I have two sets of test leads with flat blade crimps on one end and 4mm plugs for multimeter on the other end. The flat blades are in two sizes to fit blade and mini blade fuse sockets. Also usefull when injecting test supply to check operation of simulated D+ on my CBE distribution board.

 

Not quite sure how you use the addafuse holder to measure current?

 

Alan

 

 

[coach2000]

I rang Sunworks Technical and they have confirmed that I cannot get a voltage reading at the battery lugs without the battery connected as the regulator needs this to operate.

 

They are very helpful and I would reccomend the company and device's. Off the information I gave them, they were quite sure that my solar panel was working as it should at this time of the year.

 

A question for aandncaravan if you read this please. Where is the best place to connect the output cables from the regulator as I am going to tidy up all the battery wiring.

 

Clive.

[aandncaravan]

We would disagree about the majority of the Sunworks products when used in a Motorhome.

Most we have seen are far from ideal causing premature battery degradation and not the most efficient either. There are much better Motorhome specific Solar Chargers that will both look after the batteries better and give better charging.

 

Most Solar regulators work by drawing power from the Solar Panel in response to a 'load' on the regulator.

Never known a regulator to need a battery connected, just a load applied at it's output terminals and almost all Motorhomes will have a load on the Starter battery clamps (Engine ECU, Alarm, etc).

The Habitation battery clamps will have a load from the charger (despite the blocking diodes most draw some current), frost protection valve, Control Panel on standby, etc.

 

If your system uses a Sunworks regulator, it probably isn't running at any where near what you can harvest with an optimised set-up?

 

 

So I would suggest you maybe start by reviewing exactly how efficient your Solar Installation is because it maybe hasn't got the best Solar regulator? Does it charge both Starter and Habitation batteries simultaneously and have a low Float voltage of 13.4v for example?

Our Solar Power webpages contains all the info you need to assess you own installation for efficiency and best practise.

 

On the CI MH's with Nordelettronica Electronics you are probably best using a Dual battery MPPT Motorhome specific Solar regulator with outputs to the Habitation and Starter Batteries directly.

 

On the CI MH's with Arsilicii Electronics, like the AL320, the Power control unit has a built in Solar Regulator which charges both Starter and Habitation batteries. On these units you can run the Solar Panel (100w max) directly into the centre 2 pin plug without a Solar regulator. See photo.

 

 

 

 

[coach2000]

Thank you for all that info. It looks like I am going to be busy for the next couple of weeks.

Clive.