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We bought a new battery less than 2 years ago-have used it regularly without any extra charging. Last year I bought a battery charger, but OH has only got round to using it once. We have probably used the van for less than 6 weeks in those 2 years.

We went to a site with no electricity (or facilities!) this weekend, so we plugged the electric cable in on Wednesday, and it all seemed fully charged. When we got to the site on Friday night , things were okay for about half an hour after we had unhitched, then the battery warning light came on. It has 3 lights- fully charged, normal and low power. At this point all we had on was the fridge and one light. We turned the water heater on- the orange warning light came on which means insufficient voltage- so no hot water. Over the weekend the battery light would return to normal, unless we turned a light on, in which case it was red. All power had gone by Saturday night, although we had only had the lights on for about 45 minutes. There was power again after we had towed it home. We put the hook up on again last night- this morning it is showing as fully charged, and there is no low voltage light on the shower.

Our van is now 20 years old. Could it be that the battery charger in the van is not working ? Is  the battery exhausted? We are completey confused by this, and whilst we don't often go away without the hookup, it's nice to be able to do so for the occasional weekend. We also need the battery to work the water heater, and as we are going to a rally on Saturday with no facilities other than a CDP and water, a working shower is a necessity!

The oven died this weekend as well! And getting a replacement van is not an option at present.

Did you have the fridge running off the battery ?

atb

Wizard

Fridges are quite power hungry , they should be run on either mains electric or gas , 12 volts is normally used when towing .
Did you use the onboard charger to charge the battery before you went away ? , The onboard chargers don't fully charge the batterys , this and using a fridge may be why it didn't last long .

atb

Wizard

We charged it up using the on board charger- sounds like this is not very efficient. We could run the fridge on gas- but have never tried it, and in a 20 year old van you don't tend to mess with things that appear to be working happily! The water heater runs on gas, but needs the battery as well- possibly to light it?

After reading what Wizard said about the fridge, I am going to unplug the mains and see what the battery is like in half an hour- the fridge is off at present. Hopefully this will show whether it was the fridge that ran the battery down. Is there also a way of finding out whether the battery is completely exhausted and needs replacing?

Thanks for all your advice,

Caroline

I would fully charge the battery before testing to see how long it lasts .
Car accessory shops should be able to test the battery ( think it's called a drop test ) .

atb

Wizard 

The fridge really should not be able to be run off the battery at all, 12volt on the fridge should only work while towing.  Seems you have unconventional wiring there.

Yes, the fridge would flatten the battery in no time at all.  If not on EHU you need to run it on gas.

the way to test a battery is and if you have a volt meter ,chech the voltage in the batteryis 12v or more, take the caps off the 6 cells on top of the battery put the red wire to posative terminal and dip the negative into the first hole nearest the posative this should read 2v or more then do the same up to the last 1 so the next 1 will read 4v third 6v ,4th 8v ,5th10v 6th 12v, if when on the way up 1 of them reads under these the you have a cell down time to replace the battery sorry

hope this helps

karl 

Hi Karl , can't say i've heard of testing a battery this way before .
Although i understand what you mean, i think you should add a warning to your post as someone could miss-read what your saying . I would say something like ' if you don't understand how to do this test take your battery to someone who does ' . I can just imagine someone taking a wire from the positive and ( well i'm not going to say anymore incase someone does it , but the results could be explosive ) .

atb

Wizard

Hi,

You seem to have several possible problems here.

 Leisure batteries are in fact designed to be rechargeable when run down to a flat condition. HOWEVER, they will be permanently damaged if left in a flat condition.(Flat means a voltage reading of 12 volts or less) You must recharge as soon as possible when discharged.

You should have a relay fitted in to your fridge circuit to allow the 12 volt option to operate only when the vehicle alternator is running at a suitably fast rate to produce a voltage around 13 volts.

Running a fridge on a leisure battery alone will flatten even a sustantially charged battery in a very short time.

Conventional automotive battery chargers are totally incorrect for charging leisure batteries. The initial charge rate required for a leisure battery is 14 .8 volts. This is to ensure that the plates are quickly shocked as it were, to ensure that sulphation, gassing and distortion of the plates, is kept to a minimum for a short time to enable the battery to become ready to accept a bulk charge. This charge mode will be around 13.8 volts or so. The battery will accept this until capacity has been achieved, at which point the charger switches to maintenance mode and either trickles or pulses a light charge into the battery. These chargers should be kept connected to the battery and the mains permanently when the caravan is not in use. They can also be kept connected when on site on an EHU, and normal caravan/motorhome low voltage equipment can be used safely. Another HOWEVER here, do not use 12 volt sensitive equipment when charging batteries. Such things as 12 volt tv`s etc. The high charging rate from a proper leisure battery charger could cause severe damage to the equipment. I believe that this is the reason that some caravan manufacturers purposely fit the wrong chargers as initial equipment. Ordinary chargers should not cause damage, but they will not maintain a leisure battery properly either. Obviously the lesser evil as perceived by them.

Leisure battery chargers are completely automatic and can not over charge a leisure battery.

Automotive chargers (even if automatic) CAN NOT effectively charge a leisure battery. Due to an insufficiently high initial charge rate.

Hope that this helps,

David.

Thanks to all who have replied. The battery is now recharged, but OH has been reminded to do this regularly in future. Had the van serviced yesterday- due to the age of the van the fridge does seem to run off the battery, but obviously runs it down really quickly. The fridge will not run off gas- again probably due to age of van, and the servicer and I both agreed that  if it is working on EHU we should stick to EHU in future! And the valve in the oven had died- not worth replacing so we had that taken out and are going to use the remoska, so it's EHU all the way from now, unless we buy a bigger battery and do without a fridge for a weekend, which we did when camping anyway.

Caroline

The fridge being able to use the van battery is not to do with its age, but incorrect wiring.  We had a 3 way Electrolux in our 1973 Cavalier and it only used 12v when the van was being towed.

It should be able to run on gas, but obviously there is something wrong somewhere.  Not sure if that would be expensive to fix, if so you may consider it uneconomical, but you will be limiting your choice of site.  May be worth looking into what it would cost to fix.