# Are my leisure batteries kna***erd ??



## Mrplodd (Mar 4, 2008)

Just back from 1 month away in Scandaweegia. 

I have 2 x 120AH leisure batteries and a 100w solar panel. when the batteries are fully charged (13.5V showing on the info panel) and I use my 500W invertor with TV (35 watts) and Sky box (40 watts) I get about 2.5 hours of use before my invertor beeps and shuts itself down. I assume because its detected a low supply voltage.

Is this about right or am I looking at needing 2 new leisure batteries ??

I would have expecetd (possibly wrongly of course) that I should expect to get about 5 or 6 hours at that a consumption rate of less than 100 watts. I only have the usual other things running like a couple of LED lights and the gas cooker ign system !!!

I intend to visit my local battery and tyre place to get them to use a high discharge rate tester but thought I would ask here as well !!


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## inkey-2008 (May 24, 2008)

It might be just one of them but you need to get them checked you should get a lot more out og them than that.

Andy


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## Eisbaer (May 1, 2005)

Hi There,

As far as I know, a high rate discharge tester is only good for testing starter/engine batteries seeing as these are required to provide a massive jolt of current and only intermittently. The other thing is that you can't expect to get 120 amps out of a 120ah battery.....it will be flat (i.e. less than 12volts) long before you reach this figure. The battery is (usually) rated by the manufacturer at 120ah on the basis that it will give out 6 amps for 20 hrs. If you use 20 amps per hour it doesn't mean you get 6 hours of use - it's much less than this! (Google "Peukert's Exponent" to see why.) In addition, the performance of the battery will taper off with age and the number of recharge cycles. An old battery will not perform as well as a new one. If you check the voltage of your batteries with a voltmeter, first leave them sit unused for a few hours first to get a more accurate reading.

Hope this helps!


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## RichardnGill (Aug 31, 2006)

It could be the supply to your inverter is not up to the job and suffering from voltage drop? 


Richard...


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## framptoncottrell (Jan 6, 2006)

After suffering complete electricity failure from my nominal 2x110Ah batteries when only 40Ah had been used, I eventually decided that they were finished. The replacement 2x95Ah batteries were sternly tested at the Dusseldorf Messe Stellplatz: after using 120Ah over two days off hook-up, all my electrical systems were still working fine.

Of course you may have other problems, as others have pointed out, but for me new batteries were the cure.

Dr (musical, not medical) Roy


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## DABurleigh (May 9, 2005)

Even if you have no multimeter or other battery indicator, you ought to know whether or not the battery kept powering other appliances once the inverter shut down. Did it or didn't it, and if it did, what for how long? It is rather crucial to the diagnosis 

Dave


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## Eisbaer (May 1, 2005)

Agreed Dave! 

Also, batteries may be rated @ 110ah or whatever - but that's when they're new. After some use in an MH, they are significantly reduced in performance. This is because of the limitations inherent in your typical on-board charging unit as provided by most MH manufacturers. They will probably never really charge your batts. fully.....in short you don't get what you think you've paid for! New batteries may solve the problem for now but you'll probably have to change them again next year! Get rid of the inverter or only use it in an emergency e'g cup final/miss world coverage.......


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## Vennwood (Feb 4, 2007)

Mrplodd said:


> Just back from 1 month away in Scandaweegia.
> 
> I have 2 x 120AH leisure batteries and a 100w solar panel. when the batteries are fully charged (13.5V showing on the info panel) and I use my 500W invertor with TV (35 watts) and Sky box (40 watts) I get about 2.5 hours of use before my invertor beeps and shuts itself down. I assume because its detected a low supply voltage.
> 
> ...


A clue may be in your opening sentence - (13.5V showing on the info panel) as I would have expected to see at least 14v on the panel if the batteries were fully charged. With normal use and 120AH available (using a half as a rule of thumb) that should have given you much more than 2.5 hours even if you had all the lights on as well as the telly.

Get the betteries checked and replaced. Of course you could have another fault as others have said.

I give the following advice with a note of caution and only do this if you are competent and sure there will be no risk of fire etc.

An easy way of deciding if you have another fault may be to switch everything off and then disconnect the leisure battery(s) see if you get a spark when you flash the connection (you will get one the first time as it discharges the inverter capacitors) but if you have a drain then the sparks will continue.

If you have an alarm fitted to the leisure battery then this will give a small spark however alarms are normally connected to the engine battery.


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## Mrplodd (Mar 4, 2008)

Thanks for the info guys.

To answer some of the points raised

The invertor cut out but everything else was still working, the on board info panel showed the (leisure) battery condition as "fair" with I think about 11.7 volts showing. 

On another occasion after an hour or so the internal lights ( 6 x 12V flourescent) lights were noticably dim and again the on board panel showed battery as "poor" Coupling up to the mains and switching the charger on boosted the lights and charged the leisures up.

I have found the receipt and my current batteries are 3 years old. (yes they are leisure batteries made by Numax) 

I have only had the van for about 2 months, so I dont know how they were treated by the previous owner. there is a solar panel fitted which seems to keep them topped up around the 13.7 volt mark (never seen 14 V though) 

I am certainly veering towards the fact that these batteries appear to be on their last legs. as the van is still under waranty I am thinking about approaching the dealer for a couple of new ones.

I usually use hook up but whilst wild camping in Norway I need bcome a bit concerned about their apparent lack of capacity.

I can remember a previous post where some kind soul advised that I should get about 5 hours of TV (100 wats) out of a 85 AH leisure battery through an invertor, that does indicate mine are indeed knack***d doesnt it ???

Now wheres that dealers phone number ??????


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## DABurleigh (May 9, 2005)

"I should get about 5 hours of TV (100 wats) out of a 85 AH leisure battery through an invertor, that does indicate mine are indeed knack***d doesnt it ??? "

By no means necessarily, and indeed if that were the only evidence I would say the chances are not, given the prevalence of other causes of this "symptom/fault". However, with your other evidence, I would say new batteries would not be wasted 

Dave


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## lookback (Dec 4, 2005)

Never heard of a Autocruise Dakota :? Do you mean Autotrail Dakota and have you got the Sargent electrical control panel?

Ian


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## Eisbaer (May 1, 2005)

Yup - replace the batteries I'd say. There isn't a dealer/punter alive who'd sell a MH with new batteries in it. First thing I'd do after buying an MH is replace the batteries - regardless of what any voltmetre or salesman says!!


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## Mrplodd (Mar 4, 2008)

Well spotted Lookback !!!!

I do indeed have an AutoTRAIL Dakota fitted with a Sargant control unit !!

I am just about to ring them and ask what voltage should be showing whilst charging is in progress via their unit


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