# Battery Charging ?



## carol25singer (Nov 12, 2007)

In our campervan we have a 'heavy consumer' (condenser) fridge + we like to watch our 11" LCD televsion but we find our viewing time is very limited.  Am I correct in thinking that to get maximun charge from the engine alternator I need to fit an IU0U automatic charger (which could be called an electric mangament system) and can anyone recommend a make or a company reasonably local to Doncaster/Hull.  We are very limited in space and a second battery isn't feasible.


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## Deleted member 2636 (Nov 12, 2007)

You really need to fit a leisure battery for what you are asking to do. If you don't, there will come a day when you have taken just that bit too much out of your vehicle battery  and then the van "no starty"
Vehicle batteries are not designed to be used in the manner that you doing at present. They are designed for a heavy, brief discharge to kick an engine into life. Typically, they can be discharged to 80% whereas a Leisure can be taken down to 65 to 70%. Gel leisures can be taken down even further than this but they are terribly expensive


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## carol25singer (Nov 12, 2007)

*Sorry*

I didn't make this clear but we have a 110amp leisure battery which doesn't last very long mainly due to the fridge which uses 2\3 amps per hour we think.  
We're think we should be looking at a Alternator to Battery Charger, costing about £250 and which claims to charge up batteries 5 times faster, Sterling Power make them or perhaps other companies but that's the only one I'hve found on the web.  I wondered if anyone has something like this in their van?  And does it work especially for all that money!
Found another one Adverc Battery Management System, based in Wolverhampton.


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## gordon (Nov 12, 2007)

hi i have a batt to batt charger from sterling they are great for charging but they will only charge the leasure batt you have to 110 amh.so what you need is a bigger amh batt say 185 amh or get a generator.
gordon


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## shortcircuit (Nov 12, 2007)

Have you considered changing fridge to gas operation?


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## carol25singer (Nov 12, 2007)

Yes but it's an expensive 'do' to change it from a 12v to a 3 way fridge!  Would need gas and mains supply presumeably.
I know the Sterling won't charge it any more that 110amp. but I beleive that the 'normal' system won't charge it much past 70%  so if we went for a drive every other day we think that the Sterling gizmo might solve the problem?


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## tonyfu (Nov 13, 2007)

I don't know what sort of van you've got, but fitting a second hand 2-way fridge and a gas bottle could be a cheaper alternative.  Would need an external flue though.  You can always turn the gas supply off when you go to bed at night (if concerned about fumes etc) and the fridge contents would remain cold with the door remaining shut all night.  Just a suggestion.

Tony


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## gordon (Nov 13, 2007)

it's not that the normal system won't fully charge your battery but your leasure batt will read flat when it is 40% full this is to stop the battery from being damaged. check out sterling web site all info on there.
gordon


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## klex (Nov 14, 2007)

CarolSinger, here you can find a really good charger, got a CTEK 7200 myself! Depending on type there is up to five stages of charging/supplying and the charger can be left connected to the battery at all times - as a trickle charger when the battery is fully charged.
http://www.ctek.com/EN-GB/Default.aspx

Located about 8 dealers within 50 miles from Hull, use the dealer locator at the CTEK site above.

Don't understand what type of fridge you have, if it is an absorption type (3-way?) the fact is that they are heavy on energy demand, about 100W (= 8.3 Amps @ 12V) but then there is the propane alternative already built in, right?

The compressor type of fridges uses much less power, about 1/10 of the demand for the absorption type and is about 0,6 Amp on 12V. The best kind of fridges for a MH!


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## carol25singer (Nov 14, 2007)

Yes it's a compressor fridge, only runs on 12volt. I've got to admit that we would have preferrred a '3 way one'.
We've been testing the leisure battery cells and only one is at the correct level, the other 5 are too low so we're off to O'leary's Motorhomes tomorrow to 'invest' in a 135ah battery and hope this solves our problems.
The gentleman at Adverc was very helpful and the tests he asked us to do 'proved' the alternator is OK but the battery is poorly!
If we find it and the 28watt solar panel don't give us enough juice for a long weekend we still have the option of either installing an electric management system e.g. Sterling/Adverc or finding a slim-line battery that twe can fit in one of our few 'spare' spaces in the van, it's a SWB Devon Camargue based on a Renault Master.


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## HappyHippy (Nov 15, 2007)

Deleted by auther.


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## klex (Nov 19, 2007)

carol25singer said:


> Yes it's a compressor fridge, only runs on 12volt.
> ...........................




CarolSinger, really good you found the reason for the malfunction! 

The trend now - as I have noticed - is to use less propane equipment and transfer to diesel driven heaters and to compressor fridges. 
Some fundamentalists get rid of the propane altogether and don't even use it for cooking, alcohol burners works just fine.
Besides the money saved for the annual checkout and certfication of the propane system in the MH, one is also completely free to rebuild and alter the cooking and heating system in the MH to the hearts delight.


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## carol25singer (Nov 20, 2007)

Thanks everyone for your help and information, we're off this weekend to s folk song 'do' and trying out the new battery + solar panel - also going to invest in some outside silver screens next week - he doesn't know yet but we're not packing the van up for the winter - at least not so far!


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## Deleted member 2636 (Nov 21, 2007)

The current draw that your are talking about is a lot. I have tried to go the route you are talking about and eventually gave up. I went a bought a proper 12v compressor fridge from Waeco.
I run Solar Panels and you are going to need a lot more than 28w to keep up with your demands. I would suggest 80w as a minimum
A CETK is a mains charger not the type of unit that you need. The sort of thing you need is a so-called smart charger. Chas Sterling does them. So do Adverc, a very good company. Victron, Antares, it just depends how much you want to spend


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## HappyHippy (Nov 21, 2007)

Deleted by auther.


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## Tony Lee (Dec 29, 2007)

A normal vehicle alternator is designed to supply the vehicle electrical equipment which runs quite well at around 12 to 13.5 volts, and to replace enough charge in the battery to start the engine the next time. That amount of energy used to start the engine is about 300Amp-SECONDS, an absolutely piddling amount that can be replaced by a standard alternator in little more than a minute. Since the alternator is nothing more than a very crude taper charger with a set maximum voltage, the problem is not to get enough charge in the battery, but to stop it overcharging on a long drive. They do that by limiting the voltage to a compromise value well below the 14.4 volts that needs to be applied to a normal deep cycle battery to ensure a full charge. It doesn't matter for the starting battery, but for a deep cycle house battery - or leisure battery as you call it  -- it means that under the normal cycle of hammering hell out of the battery overnight and then driving for a couple of hours to the next wild camping spot - or even worse, idling the engine for 20 minutes -- the house battery is chronically UNDERCHARGED and may rarely get beyond 70% charge even after several hours of driving. Note that the charging voltage you read on a meter is no indication of how full the battery is. Only the resting voltage gives any sensible indication. This constant undercharging guarantees a short battery life as well.
Since a battery shouldn't be regularly discharged below 50% or below 40% for AGM batteries, this means your effective safe usable capacity is 70%-50% = 20% and for a 100AH battery represents only 20AH. A big TV and a fridge drawing 3 amps and the battery is suffering by the time "The Bill" is finished.

Solar - of sufficient size - overcomes this problem because the 3-stage solar regulator can take the battery to 100% capacity if not every day, at least occasionally. Another way is to use a car alternator with a "smart" regulator that will also fully charge the house battery, or there are other systems that take the engine battery supply and invert/convert it to a higher DC voltage that makes it a three stage charger as well.

Here in Australia where caravanning is very popular, but solar is rare - and even in motorhomes without adequate solar, another way to properly charge the house battery while on the move is to use the 12VDC-240VAC inverter that many have in their van and the 3-stage mains battery charger that most also have. Get the 12V supply for the inverter from the engine system, feed the 240V to the charger, and charge the house battery from the charger. Over the full charge cycle, this is a more rapid charge than direct from the alternator AND charges the battery fully AND uses only the equipment already installed in many MHs.


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