charging a battery
I have been reading the discussions re batteries and noted that members advise charging a battery occasionally to top it up because the onboard chargers do not perform.
My question is- if you take the battery out of the caravan to charge it does the 12 volt and 240 volt systems in the van still work e.g. the fridge.
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The fridge cooling element only runs on 12v when connected to the car. The fridge control panel is fed continuously by the leisure battery so no battery = no control battery = no fridge.
Most onboard battery chargers require the battery to be in place to complete the circuit when using mains hook up.
Tbh, I’ve never come across anyone removing a battery to charge it while the van is in use on mains hook up. Likewise, I’ve not heard of onboard chargers not keeping the battery charged enough. People tend to remove and charge batteries when vans are parked up and not connected to the mains. Obviously, if you are not hooked up the battery will not be charging and your 240v appliances will not work.
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no the 12v will not work ( I think ) never tried doing it. if your connected to the mains then 240 will work. on board charger will charge the battery to capacity as that is what they are for. I think you might be mistaking having the caravan in storage and the battery will lost its charge and needs a boost about 4/6 weeks to keep in good condition. that's why a lot of owners fit solar panels as these will charge the battery and you don't need to visit as often.
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" no battery = no control battery = no fridge."
Sorry, should read "no battery = no control panel = no fridge"
My thoughts too, LL, a confusion over a van in storage as opposed to one in use.
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OP does NOT say that his charger 'does not perform' ..... he says that he has read that the onboard charger will not fully charge the battery.
This view is often expressed regarding chargers with a fixed 13.7/13.8v output. This is NOT true. The battery will eventually reach a fully charged state, but this may take quite a few days.
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Agree, the OP is under the impression that all onboard chargers do not perform. Later ones will perform .... in time. Whilst in storage I remove mine and maintain it with my CTEK 10a charger.
Not understanding the second paragraph though, where is the caravan when you would want to do this? If on site connected to EHU then it does not matter as the battery will be in a decent state of charge anyway.
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My question is- if you take the battery out of the caravan to charge it does the 12 volt and 240 volt systems in the van still work e.g. the fridge
Do you mean will they still work if you are connected by EHU?
Well on certain caravans (Mine - Swift) it does not recommend doing this at all, something to do with the battery 'smoothing' something? I am sure someone will be able to give a better description?
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Generally speaking, the charger that is fitted to the caravan will maintain the battery while connected to the EHU.
There should only be a need to put a freshing charge to the battery if it’s not being used regularly.
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Thank you for all the replies. I asked the question because my inboard charger was not performing while I was on EHU in Spain for 6 months. When I came to get off pitch the mover only worked in short spurts. I was told it was the battery so I guess it was knackered by being continually undercahrged during that time. I have read a lot about this on forums, and understood very little. I have replaced the inboard charger, £127.00, and I am now about to buy a battery. Incidentally the NCC Guidlines say that I should use a Grade B battery, I have just realised that mine is a grade C, 110ah Plantignum sold to me 2 years ago by a reputable caravan dealer, who was advised of my requirements!
I will fit the new battery and see how it goes with new charger. I will buy an intelligent charger as well, just in case! I had a Ctech which packed up after 3 years.
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As usual, people make comments on this forum without having the technical knowledge to do so and it is very frustrating to read incorrect advice. I am always happy to learn if somebody has superior knowledge so please feel free to correct me if you think what I say below is wrong.
Many caravans (and most motorhomes) are now fitted with smart charging systems. Assuming they perform correctly then they will maintain your leisure battery in optimum condition. However, several major manufacturers (such as Bailey unless they have changed recently) have fixed voltage/fixed current transformer rectifiers which both charge the battery and provide a nominal 12volts to auxiliary systems. They are fixed at around 13.8 volts come what may, rain or shine, flat battery or not.
Most sealed batteries require around 14.4 volts to fully recharge a discharged battery. If you provide a lower voltage then the battery chemistry will not properly work, you will get sulphation and reduced battery life. On the other hand, if you provide 13.8 volts permanently on EHU you will drive excessive current into the battery and it will age prematurely. The 13.8 volts is a compromise which will keep your battery working without damaging your equipment which is only designed for a nominal 12 volts.
So, if you have a basic charger which the majority of Caravanners probably have then you should do the following. Firstly, do not leave your EHU connected when the caravan is not in use. Secondly, if you are off grid and your battery is discharged, take it out of the van and do a full recharge preferably with a smart charger. This will apply a controlled voltage and current profile to give optimum conditioning. If your van is in storage then every 1-2 months take the battery out and recharge it with the smart charger.
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Lornalou, to fit a decent system like Sargent I would think would cost several hundred pounds including installation as a retrofit. I haven’t looked at all the wiring diagrams but a smart system should take the battery offline whilst charging it but still providing a fixed voltage to the caravan auxiliaries so I don’t think that it is a straight swap using the same connections.
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A 12 volt lead acid battery consists of 6 x 2 volt cells - 2.2 volts fully charged, giving a fully charged voltage 13.2 volts. Trying to raise that voltage over that will “cook” and damage the battery.
A charger putting out 13.8 volts will fully change a 12 volt battery.
One that puts out a higher voltage will charge it a bit quicker.
Excessive ampage pushed through a battery is what causes the battery to get hot and does the damage.
now I do not claim to be a expert on batteries, but my knowledge is from a few years working as a C&G qualified auto election. And I bow to those specialists who are.
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I had similar problems with my mover: bad connections to motors. Seemed like a low battery charge, but worked fine after cleaning and refitting wires.
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Interesting then that a CTek smart charger recharges at 14.4 volts. Perhaps they got the design wrong.
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All smart chargers read whats in the battery when first connected. this determines what the voltage and amperage will be required and deliver that to the battery. if the battery is on the low side it will deliver approx 14.7 volts to boost the charging process and will lower that input as the battery takes a charge. My smart charger at home has a digital display and connecting will start at 14.7 after a couple of hours will sit at a constant 13.4v.
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Quite so. It starts at a higher voltage and reduces but it doesn’t start at 13.8 volts. 14.4 volts for gel or sealed, 14.7 volts for AGM. If you supply 14.4 volts on the caravan charger it is excessive for the 12 volt power consumers so they provide 13.8 volts but no initial higher charge which is essential.
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