# Domestic Battery Failing?



## Smokeyjoe (Nov 30, 2009)

On the basis that use of all our domestic systems is very sporadic, and not too bright electrically, I've always avoided getting into the sums of battery capacity versus consumption (we never had problems with 2 domestic batteries on our boat, with a Sterling mains charger). 
However, we're having probs with our 1 year old Nexxo T660. Although purchased new, it was a 2009 vehicle. Trouble is we can't do a winter weekend not on hook up, using the heater and TV (one evening of TV and mostly just a Fri and Sat night of heating) without the 12v protector cutting power off by mid-Sat night. The van sits on the drive at home permanently plugged in. The leisure battery is a Varta G14, 95 aH. Are we switching the heating on and off too often (5.6aH on start up), or does it sound as if there's something wrong? Lights are now low energy.
A short rest and we've got power for lights, etc, or a half hour's drive and the heating seems OK for a bit. Is the cut-off too enthusiastic, or maybe the battery's had it?
We're thinking of a second battery as the first attempt at improving capacity (I don't see much value in solar in winter months).
I know it's a big question with many variables, but I'd like to know if we're expecting too much. I don't see how we can have knackered the battery with such a readily triggered battery cut off!


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## erneboy (Feb 8, 2007)

You can up you capacity on spec and see if that cures the problem or you can do the sums and test the battery you have. My guess is that your battery is inadequate and possibly knackered, but only you can find out. I recommend some sums and a check with a multimeter, Alan.


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## trevorf (May 16, 2005)

A multimeter will not fully test the battery. You really need a load tester on it.


Trevor


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## Smokeyjoe (Nov 30, 2009)

Thanks everyone, but is it possible to conclude any observations on what we are currently managing to achieve, endurance-wise?


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## erneboy (Feb 8, 2007)

Not without knowing your power usage. It is true that you cannot fully test a battery with a multi meter but knowing how much power you are using and keeping an eye on the voltage will give you a fair idea. A drop test will give a definitive answer. It has recently been demonstrated on here that a load tester, as used by many garages and Halfords etc. may not. It's quite likely to pass a duff battery as OK because it only applies the load for a few seconds, Alan.


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## joedenise (Jul 20, 2007)

Hi Joe

We can do 4 days with both heating and TV but I did upgrade to 2 x 100aH Elecsol batteries. Seems you have a similar van to ours, we have t615, battery under the seat by the door, just needed to move the middle board forward a little to get 2 batteries in.

Joe


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## teensvan (May 9, 2005)

Hi.

Easy test for your battery. Connect across your fully charged battery 13.8 volts a 12 volt 12 watt lamp. Remember to take the battery off charge. If your battery is an 80 amp hour job it should last for at least 40 hours, and the battery should not be less than half discharged or over 12 .2 volts. If the lamp is only a yellow glow after the test then the battery is U/S. You can get small multi meter testers for less than £10.

Hope this helps.

steve & ann. ------ teensvan


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## Smokeyjoe (Nov 30, 2009)

teensvan said:


> Hi.
> 
> Easy test for your battery. Connect across your fully charged battery 13.8 volts a 12 volt 12 watt lamp. Remember to take the battery off charge. If your battery is an 80 amp hour job it should last for at least 40 hours, and the battery should not be less than half discharged or over 12 .2 volts. If the lamp is only a yellow glow after the test then the battery is U/S. You can get small multi meter testers for less than £10.
> 
> ...


Thanks Steve and Ann,
Getting my head round a multimeter always eluded me, so this will be a very practical test, though from reading the van manual, it seems so many bits of kit have a slight battery drain, even with the 12v switched off, that I'm inclined to disconnect the battery once fully up. Presumably this is OK.


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## Smokeyjoe (Nov 30, 2009)

joedenise said:


> Hi Joe
> 
> We can do 4 days with both heating and TV but I did upgrade to 2 x 100aH Elecsol batteries. Seems you have a similar van to ours, we have t615, battery under the seat by the door, just needed to move the middle board forward a little to get 2 batteries in.
> 
> Joe


Thanks Joe, hope you are pleased with your van too. Getting a second battery, a) to use in place of the existing one to compare, and b) ready to install alongside the existing one or its replacement, seems a good idea.
I know it's a whole new question, but are there any issues in installing different make(same capacity or slightly different) in tandem? Or if one is somewhat (but not totally) reduced performance. The Elecsol sounds significantly cheaper than my Varta.
Sounds like your charger is up to it; Mine (I think, from the German manual) is a Schaudt Adapter DP02. Looks, from this manual - my German is minimal - that this gives a max charge of 2 amp. This sounds low, esp when I read about the performance of Elecsol batteries with a 10 amp charger, as if this is normal.


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## joedenise (Jul 20, 2007)

Hi Joe

very pleased with our motorhome use it as much as possible.

as to the batteries i took the old large Varta out and the tray underneath moved the panel in front of the old battery forward as much as possible (its only held in by 4 screws ) and put the new batteries in the other way a round they only just fit.

If you need any more help pm me

the charger in mine can put over 20 amps in when the batteries are low

joe


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## erneboy (Feb 8, 2007)

You will be able to download English versions of Schaudt manuals I think. I doubt your charger is only 2 amps it would not keep up with normanl demand for most people if it was, Alan.


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## Smokeyjoe (Nov 30, 2009)

joedenise said:


> Hi Joe
> 
> very pleased with our motorhome use it as much as possible.
> 
> ...


Thanks so much; however, before I go down the route of replacement batteries (which I will), something has occurred to me. On further googling and pouring through the manual yet again, I've concluded that the Schaudt Adapter is not the actual charger, but that the Elektroblok EBL 99 is. This means the words '2 amp max' I've seen in the German language manual of the Adapter are not related to the max charging rate of the battery. So far, so good, but I've seen posts of faults with Elektrobloks, so it occurs to me that the only charge getting to my leisure battery may be when we've run the engine (typically 100 miles) , so what I plan is to simulate a weekend's use on the drive, with the hookup disconnected, running the fridge/heating/TV/lighting etc as we would if away. If the battery flattens even quicker than it has been, my conclusion could be that the EBL does have a fault, and is responsible for the shortened life of my leisure battery. It should all be under warranty but my dealer is miles away (another lesson learned here too!).


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## joedenise (Jul 20, 2007)

you should be able to see if its charging on hook-up or with the engine running from the control panel - ours is above the hab door - there is a charge/discharge meter, even when we've had a long run back from the continent and plug in just to keep the fridge running it always goes into the +ve for a short time so it shows that it's charging the hab batteries.

If you start the engine with the 240v disconnected you should be able to see the same thing.

Joe


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## Smokeyjoe (Nov 30, 2009)

joedenise said:


> you should be able to see if its charging on hook-up or with the engine running from the control panel - ours is above the hab door - there is a charge/discharge meter, even when we've had a long run back from the continent and plug in just to keep the fridge running it always goes into the +ve for a short time so it shows that it's charging the hab batteries.
> 
> If you start the engine with the 240v disconnected you should be able to see the same thing.
> 
> Joe


Thanks Joe, clearly a very useful tip, especially to me, with very likely the same electrical gear. I guess that means I don't need to worry about holding the meter button down while waiting to see the response - I've read this is a no-no for the water tanks!


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