Leisure batteries system sending me crazy----HELP PLEASE----

[John Proctor]

The old saying .... climbing the walls ... is an understatement!
2001fiat ducato benimar europe st 6000 ... proper straight Flys through its mot over the 3 years I've had it.... love it to bits... However me and my trusted benimar are about to proper fall out I've looked and tried everything to stop this problem ...
I am reaching out for that one thing I haven't done to fix this problem.
New under bonnet starter battery cranks spot on.
A 110 ah leisure battery under both front seats that charge to 13.6 / 8 when I start the engine, checked by a multimeter and also showing the same on the control panel. All the motorhome Internal lights work and everything else as they should. So here's the problem, when I turn the engine off and test the batteries there sat at 13.6 / 8. Then turning just the habitation lights on the voltage on the control panel drops very quickly and within 4 minutes it's down to 7 and the lights have dimmed before going out. I then check directly to the batteries and they were sat at exactly what the control panel was reading...
I change the battles to two 130ah Gel batteries that I new were ok as I had took them off my garage solar system ... the same is happening with them... good charge .... lights on very quickly down to 7 lights out ...
WHAT ELSE CAN I CHECK I AM GOING OUT OF MY MIND....
HELP PLEASE

 

[Phill D]

See post #5 have you charged the battery then let it rest for 30 minutes then with no load on taken the voltage?

Then put the meter on the battery and switch on a light and note the changes in voltage.

Or a clamp meter and monitor the current from fully charged when you switch a light on.
Without proper testing you will not find the real problem..

 

[autorouter]

It looks like you've used your 5 free posts, and now need to subscribe (£20) to post any more. Many people say it's the best £20 they've ever spent on a motorhome.

Don't be misled by the battery voltage, you may be thinking it's fully charged when it's nothing like charged. Charging a flat battery takes several hours - at least 4 hours if very flat.

A battery that's not being charged, and has no load on it, will gradually settle to its 'resting voltage' after an hour or more. That resting voltage will more or less indicate the percentage State Of Charge (SOC). There are charts available for this, each battery type is slightly different, but they are all similar. Usually from 12.0V to 12.8V for most batteries that are not very flat.

To charge a battery you apply a higher voltage than the resting voltage, to force charge back into the battery against the normal flow. Charging is a chemical process that turns lead sulfate into lead and lead oxide at the battery plates. It takes time, often many hours. If you measure the voltage while that is happening, it definitely doesn't tell you the state of charge. If you want to find the SOC by measuring voltage, you have to disconnect the charger and let the battery settle to its resting voltage again.

I think your batteries are beyond saving, but if you want to give them the best chance, you need to put them on charge with a mains charger for several hours. If they were mine I'd go for 24 hours. Then see what happens if you put a small load on them.

With all battery problems like this, it's important to test whether it's the battery that's failed. If it has, it's then important to find if it's just a failed battery, or if there's something about the setup that's causing them to fail. You don't want to buy new batteries and have them fail in a few days or weeks.

That's why you should try to find out if there is any unusual drain on the batteries while they are connected, and you think everything is switched off. There are several possible candidates - modern electronic control units can fail to go into 'deep sleep' mode when turned off, and continue to draw a current. Or it could be as simple as a light not switching off when a wardrobe door is closed.

 

[ChrisL]

I've put two batteries that are good and holding there charge but on the van the voltage is showing the same as the other ..dropping within 4 or 5 mins with just the light being used

What you are describing is typical of sulphated batteries, because they hold their charge with no load does not mean they are good, they have become sulphated to the extent that the batteries capacity has been severely reduced and the voltage will drop with even a small load like lights. You need a new leisure battery and if it's a Gel battery it needs and extended absorbition phase of perhaps 8-10 hours to become fully charged.

Here's a gel battery that I tested earlier this year, note the voltages before the test runs and whilst the test was running, the load was set at 2 amps the battery is less then 3 years old but is sulphated beyond recovery.

 

[Jimhut]

As Phill D said, you need to use an ammeter to find out what is really going on.
Incidentally, check the wattage of your light bulbs. You may have the old filament bulbs which could easily be 50w each, ie a 4 amp drain per bulb. Definitely change them all to LED.

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[headlight]

As Phill D said, you need to use an ammeter to find out what is really going on.
Incidentally, check the wattage of your light bulbs. You may have the old filament bulbs which could easily be 50w each, ie a 4 amp drain per bulb. Definitely change them all to LED.

"easily 50 watts each"
In my experience motorhome bulbs if non led are normally 10 watts for internal lights and about 20 watts for an external awning light.
I personally have never seen 50 watt internal light bulbs.

 

[mohawkman]

Hi John, you need a new leisure battery. All batteries have a finite life and it sounds like yours have gone to meet their maker.

You have a couple of options; if your battery used to cope with all your leccy requirements, just replace it. If you'd like a bit more power then investigate (Lithium) LiFePO4. Meanwhile, welcome to the fun

There is still a great test but very old and that’s an Hydrometer!! Unfortunately some batteries are sealed and even if they aren’t only us old ‘ins know how to use one !!!

 

[MisterB]

Will an old MH charger handle LiFePO4 batteries though?


Re having a suitable on board charger ...

My charger doesn't have a lithium setting so I charge on a LA setting. It charges close to 96% - which is fine, solar if available does the rest AND some might suggest not charging to 100% will extend the life of the battery ...

 

[autorouter]

"easily 50 watts each"
In my experience motorhome bulbs if non led are normally 10 watts for internal lights and about 20 watts for an external awning light.
I personally have never seen 50 watt internal light bulbs.

True, but before I converted to LED, the main lighting in my 2006 Hymer was four 10W downlights. Converting to LEDs is the nearest thing you'll get to a free lunch. About a tenth of the power consumption and heat, for the same amount of light. And they last almost forever. I converted mine in 2014 and bought a spare LED lamp just in case. I've still got it, unused.

 

[autorouter]

There is still a great test but very old and that’s an Hydrometer!! Unfortunately some batteries are sealed and even if they aren’t only us old ‘ins know how to use one !!!

Some sealed batteries have a buttons visible through a transparent cover, that changes colour with the state of charge - I think that works on the hydrometer principle. However Gels and AGMs don't have liquid acid electrolyte, so can't use one of those.

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[starquake]

Clamp on multimeter (peakmeter) from amazon or similar should IMHO be in every motorhomers toolkit. You just clip it to the + of battery terminals (round the cable) and it'll show you the live usage of the battery, ie, if you have a hidden something using all the electricity. Theses are like £25 these days, a far cry from when they USED to be £100+. https://www.amazon.co.uk/dp/B0CZK6R9FN/?tag=mhf04-21

Clip it on cable check the actual usage once the master switch on, quickly with a charged battery and should tell you if any draw happening you don't know about. If the usage is nil the battery is goosed.

Though with the volaages it does sound like your battery is goosed/perminanetly damaged/sufated now. With voltages that low, it'll never be repairable.

Just posting to let the original poster know a cheap clamp on meter may be of use to diagnose any draw. (above is an example cheap one I found, I use a similar one but the one I purchased isn't sold anymore!).

 

[headlight]

True, but before I converted to LED, the main lighting in my 2006 Hymer was four 10W downlights. Converting to LEDs is the nearest thing you'll get to a free lunch. About a tenth of the power consumption and heat, for the same amount of light. And they last almost forever. I converted mine in 2014 and bought a spare LED lamp just in case. I've still got it, unused.

I had 11 x 10 watt internal bulbs and a 20 watt external awning bulb.
Changed all the internal bulbs to G4 leds, 2 watts each so a fifth of the power and brighter.
Changed the awning bulb for a 4.8 watt led, again brighter than the original.
So if I had all my lights on with the old bulbs it was 130 watts total.
Now with leds with them all on it's 26.8 watts total.

 

[Garveypeter]

Hi Ian. Batteries change to 13.6 sometimes when I tested then they were sat at 13.8

Voltage in isolation means little so disregard, as volts x amps = power in watts and you can’t power anything bar a couple of bulbs for a short duration. It seems your battery is reading 12v + but the battery has minimal capacity and can’t power a few light bulbs for any duration.

 

[FrankNicklin]

Changed all my internal bulbs to LED and what a difference. I bought some LED panels from stem Lighting one for the bathroom and one for the awning light, an LED bulb just didn’t cut it.

The awning panel light is fitted with a 15mm Bayonet adapter and the panel faces outwards so all the light go to where you want it. I put a G4 panel LED in the bathroom as that needs to be nice and bright. I replaced a total of 11 bulbs in total that were 10w each.

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