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I am looking at building a new van. I have a T4 with a 110 amp/hr leisure battery at the moment and it lasts ok when I go away for a weekend but I do need to drive it or start the engine occasionally. I have a Waeco coolbox and I run some interior lights and a iPod dock.

How many batteries do you have in your van and how long does it last without hook up?

Thanks
 

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I used to run two 110amp hr ones and I really only had a TV and LED lights.

But my new van is going to be for site camping so I was going to just use one.. I only once had it go flat with two and I was also running a cool box and that was after a day and a half.

with two battery's, hmmm I may go back to two of them we will see. I guess people will ask are you doing wild camping or site.
 

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Got a standard battery off ebay-950 amps-£50 no probs as of yet and lots cheaper T:
Made some brackets up and stuck it under drivers seat!
 

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950 amps cranking i do believe-original fitment on big disco diesels etc :)
thats what it says on the label-top of battery!!
 

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I used to run two 110amp hr ones and I really only had a TV and LED lights.

But my new van is going to be for site camping so I was going to just use one.. I only once had it go flat with two and I was also running a cool box and that was after a day and a half.

with two battery's, hmmm I may go back to two of them we will see. I guess people will ask are you doing wild camping or site.
So without a hook-up would you say you ideally need 3 or 4?

Is there a calculation to work out how long the alternator would need to be running to charge them?
 

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ive got two 95ah and they last about 3 and a half days from full without topping up,i have a weaco crp40 fridge leds inside led awning srtip light and a 15" lcd

you need to pick a decent deep cycle leasure battery car batteries are no good and will die in no time what so ever
3 or 4 batteries just aint needed unless your gonna park up for a week in a field
 

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I've put one 110ah under the passenger seat, and when I put my fridge in I'm going to see how it holds up, and possibly fit a second second at the bottom of the wardrobe if it's needed... I can't see me needing more than 2 days of fridge anyway...
 

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I've got 2x110ah boys in mine. will run all my leccy with compressor fridge use for 4-5 days no bother, I also have a Sterling 50a Battery to Battery charger so an hour of running around soon blasts them back to a good charge state even if they do run down a bit, it's an expensive box of tricks but needed for us as I can't get the van near the house to put on a charger at home.

The std alternator is gonna take a few hours to charge back up those batteries you're on about with a split load relay.....
 

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Ok cool thanks. I recon it will be 2 x 110s then. Just need to find a fridge that is no
More juicy than my coolbox now so I can have a good 3 day weekend away without going flat.
 

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In the 'van I just sold :blg there was 2x 85a/h batteries, and I suspect no one is going to believe that fully charged, (using a CTEK smart charger ;) standard chargers and alternators will only fill batteries to about 80% you know!) Running fridge and LED's it would last 10days to 2 weeks, with no charging, not even off the engine! And that is running the fridge at 2degrees!

Any secret to this? Well, the biggie is the fridge, it's a Waeco CB-40 Coolmatic, 40 litre top loading fridge using the very efficient danfoss compressor - it only draws between 1.2 & 1.8a/h max. Running time varies a little depending on the ambient temp, and being a top loader, you don't lose any cold air every time you get a beer out of it. Not a common fridge type, but you can still get hold of them and certainly worth considering if planning a build. Also, you can adjust the thermostat to use as a 2star freezer, but that would use a bit more juice.



Also, no TV or ICE running off the leisure batteries just the LED lights and a phone charger.
 

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In the 'van I just sold :blg there was 2x 85a/h batteries, and I suspect no one is going to believe that fully charged, (using a CTEK smart charger ;) standard chargers and alternators will only fill batteries to about 80% you know!) Running fridge and LED's it would last 10days to 2 weeks, with no charging, not even off the engine! And that is running the fridge at 2degrees!

Any secret to this? Well, the biggie is the fridge, it's a Waeco CB-40 Coolmatic, 40 litre top loading fridge using the very efficient danfoss compressor - it only draws between 1.2 & 1.8a/h max. Running time varies a little depending on the ambient temp, and being a top loader, you don't lose any cold air every time you get a beer out of it. Not a common fridge type, but you can still get hold of them and certainly worth considering if planning a build. Also, you can adjust the thermostat to use as a 2star freezer, but that would use a bit more juice.



Also, no TV or ICE running off the leisure batteries just the LED lights and a phone charger.
10 days to 2 weeks without charging from 2x85ah batteries sounds very optimistic / impossible for running just the coolbox, unless you are nearly or completely discharging your batteries? I just checked the specs for the CB40 to see how much better it is compared to my older Waeco, at 20 degrees the spec says it uses about 15AH over 24hours, mine uses 20AH. So over 10 days that is 150AH, you only have 170AH available when the batteries are new. I personally wouldn't want to run just the coolbox for more than 5 days without charging as its common practise to not discharge more than 50% of capacity else your batteries won't last very long. Or you could add a solar panel, I have an 80 watter and find this balances the coolbox power consumption really well.

I'd also have to disagree with the general conception about batteries never being fully charged by the alternator. Modern alternators regulate at between 14.4 - 14.8 volts so they will put the bulk of the power back into the battery very efficiently. (Depending on your wiring etc.) Once the battery reaches the regulated voltage the battery will be about 90% charged but it won't just stop charging, its just this final 10% might take another 8 hours or more. So for most people they will still fully charge their leisure batteries between camping trips if it is their daily driver, otherwise a solar panel or a mains charger is a good investment.
 

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10 days to 2 weeks without charging from 2x85ah batteries sounds very optimistic / impossible for running just the coolbox, unless you are nearly or completely discharging your batteries? I just checked the specs for the CB40 to see how much better it is compared to my older Waeco, at 20 degrees the spec says it uses about 15AH over 24hours, mine uses 20AH. So over 10 days that is 150AH, you only have 170AH available when the batteries are new. I personally wouldn't want to run just the coolbox for more than 5 days without charging as its common practise to not discharge more than 50% of capacity else your batteries won't last very long. Or you could add a solar panel, I have an 80 watter and find this balances the coolbox power consumption really well.

I'd also have to disagree with the general conception about batteries never being fully charged by the alternator. Modern alternators regulate at between 14.4 - 14.8 volts so they will put the bulk of the power back into the battery very efficiently. (Depending on your wiring etc.) Once the battery reaches the regulated voltage the battery will be about 90% charged but it won't just stop charging, its just this final 10% might take another 8 hours or more. So for most people they will still fully charge their leisure batteries between camping trips if it is their daily driver, otherwise a solar panel or a mains charger is a good investment.
Just knew this would come across as unbeleivable LOL: tho am glad you gone and checked on the stats on the fridge first ;) without checking rigorously against the manufacturers specs I'm not going to argue about consumption, but the 20degrees is over 24 hours, how often you known it to be that temp at night? We're lucky if we get that temp for a few hours a day in this country! So, it's likely they are stating max power usage, in reality they will likely be using less power, would you agree?

About the only discharging to 50%, never heard that before, and as far as I'm aware, deep-cycle leisure batteries are happy to be almost completely flattened between charges, it's only starter batteries that you aren't meant to run completely down - could be wrong here, I been wrong before, once or twice ;) The compressor used on these will also run when battery is quite depleted, I think voltage has to drop to 10.5v before it stops, though it still needs to be able to get a reasonable ampage (15amps I was told by the engineers at Dometic in Blandford Forum when I went to get the controller on it replaced) for the compressor to begin running, but this is only needed for milliseconds apparently.

Also, the charging upto 100% thingy is something I have repeatedly seen on various threads here, and it's repeatedly been mentioned that it's not possible to fully charge using the alternator or a standard charger, which is why so many do swear by using intelligent/smart charging systems like the CTEK.

So, to conclude, if you want to run your fridge whilst away from mains power, spending a little bit extra on one of these fridges will give you at least 33% Longer in the field than Phoenix's waeco cr65(?) an these are actually older models that the cr65/50 I believe, mine was fitted in '99 when the bus was initially converted. Only place I could find with supplies when I looked earlier was in the US tho, but am sure you should be able to get hold of them in this country if you spend a little time looking and calling around.
 

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I've got x2 125Ah mounted in the back, they'll do the CR50 Fridge and a few lights, with the occasional phone charge for about 2 weeks before needing the top up the batteries again A:
 

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I have looked into this subject quite deeply and almost to the point of being . I ended up putting a 225Ah alkaline leisure battery in the back of my wagon. I never have a problem with it running low but I would recommend putting a solar pv to it to trickle charge just to keep it topped up on long trips away. You can buy these quite cheaply nowadays. Another thing to be aware of, ideally you do not want to run the battery down below 50% (as stated on previous posts) as it will damage your cells. I hope this helps. I got the battery for about £145 or their abouts. T:
 

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Just knew this would come across as unbeleivable LOL: tho am glad you gone and checked on the stats on the fridge first ;) without checking rigorously against the manufacturers specs I'm not going to argue about consumption, but the 20degrees is over 24 hours, how often you known it to be that temp at night? We're lucky if we get that temp for a few hours a day in this country! So, it's likely they are stating max power usage, in reality they will likely be using less power, would you agree?
You didn't actually say what time of year it was so I assumed summer which is when probably most peeps use their vans and is when the coolbox works hardest. So in summer when its sunny I find my coolbox uses on average around 20AH a day in the UK, I know this is accurate as I have an accurate amp hour meter. This is what Waeco quote for a 20 degree constant temp, I put this down to the fact that in the sun the inside of the van can get considerably hotter than 20 degrees in the day. No reason to think your coolbox wouldn't uses 15AH a day under the same circumstance?

About the only discharging to 50%, never heard that before, and as far as I'm aware, deep-cycle leisure batteries are happy to be almost completely flattened between charges.
Yes true deep cycle traction batteries maybe (Golf Carts / Forklifts etc) but for normal deep cycle batteries used for motorhome its one of the quickest ways to kill them as each time you fully discharge them it will reduce the total capacity. ie. Your 85ah battery becomes a 75ah battery etc. Its good practise to discharge a battery by the minimum amount to extend its life and the 50% rule of thumb is quoted for the maximum discharge.

think voltage has to drop to 10.5v before it stops
That is 10.5 volts when the battery is under load, if a battery ever showed that voltage when its not under load its kaput.

Also, the charging upto 100% thingy is something I have repeatedly seen on various threads here, and it's repeatedly been mentioned that it's not possible to fully charge using the alternator or a standard charger, which is why so many do swear by using intelligent/smart charging systems like the CTEK.
I wouldn't take everything as gospel on here as how many people ever check if their batteries are fully charged, obviously the suppliers of wiz bang chargers want you to believe that you need their chargers to properly charge your battery. I agree some of these chargers are useful if you have a battery on a vehicle you don't use regularly motorbike / motorhome etc. as they will float the battery once its fully charged so can be safely left connected all the time.

I'd also agree the average split charge system with 4 - 6mm cable wouldn't completely charge the battery very quickly, but would still get there given enough time. I'm talking about a no loss split charge system, with properly specced cable for minimum voltage drop at high currents, good connections and a high quality relay. If anyone is interested have a look on http://www.canalworld.net/ as there are a couple of proper experts when it comes to 12 volt electrical charging systems. The guy who developed the smart gauge posts on there and he's a real battery boffin.
 
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