Van batteries charged by car?

Sheba · Guru

Van batteries charged by car?

rockylizard · Guru

Gday...

I had mine checked out because it appeared that the car was not charging the battery when driving.

The autoelec found there was nothing wrong and all was as it should be.

His advice was that, when driving to charge a van battery, it takes twice as long for the car's alternator to restore the battery as it took to use it - eg use it for two hours last night, need to drive for at least four hours the next day to get it back to "full". I very rarely drive for four hours uninterrupted and rarely that long in a day.

Hence, I got solar panels, they charge ALL the time (as long as there is sun - or very little cloud) driving or not.

Cheers - John

-- Edited by rockylizard on Monday 16th of July 2012 08:22:24 PM

KerryandBruce · Veteran Member

Can you tell me if the caravan batteries are meant to be recharged while driving? Thought they did but ours doesn't and we don't know why? Don't really want to spend every 3rd night at a caravan park if we don't need to.

Happywanderer · The Master

I would have thought so Kerryandbruce. Are you sure your connection isn't faulty.

KerryandBruce · Veteran Member

No Happy, I contacted the previous owner and he said his never did either.

Happywanderer · The Master

Do you mean he never checked the connection or never charged the batteries while driving?

KerryandBruce · Veteran Member

The batteries never charged while driving for him either.

Sheba · Guru

Are you sure the 'Van batteries are connected to the Vehicle properly ? If so, they should be charging.

I'd be getting an Auto-electrician to check it out.

Cheers,

Sheba.

KerryandBruce · Veteran Member

Agree Sheba, they are connected so will head off to Auto electrician. Just thought we might have saved some dollars

Happywanderer · The Master

There would be some way to charge the van batteries. As Sheba says get it checked out by and AutoElectrician. I would be having it rewired to make sure it does charge.

rockylizard · Guru

Gday...

It is usual these days that there is an Anderson Plug on the vehicle and also on the van. The vehicle charges the van battery through that.

I assume you have an Anderson Plug?

Cheers - John

rockylizard · Guru

Gday...

Bit more info on Anderson Plugs and the 'typical' wiring.

Cheers - John

gst · Senior Member

The old way was the live on your trailer plug would slowly charge your battery but this day and age you need a connection from your elec sysm to an Anderson plug if you where in Townsville I could check it for you.

Sheba · Guru

rockylizard wrote:
Gday...
Bit more info on Anderson Plugs and the 'typical' wiring.
Cheers - John

Thanks John. Now I know what to look for tomorrow.

Cheers,

Sheba.

ozjohn · Guru

As well as 6B&S wiring through and Anderson Plug you'll need to check out the vans Smart Charger (If fiited) to see if it has a DC DC fuction, as the vehicle alternator won't fully charge a deep cycle battery.
OJ

PeterD · Guru

KerryandBruce wrote:

Can you tell me if the caravan batteries are meant to be recharged while driving?

The majority of vans are not wired with a battery or provision to charge a battery in them from the tug. Battery installations in vans are an individual installation. There are some small manufacturers that do provide vans for bush camping but they are in the minority.. One problem in answering your question is you did not tell us what your van and set-up is.

From your avatar it looks like you have a Jayco pop-top van. If this is so then let's look at the standard Jayco installation. The lighting is 12 V with the power is supplied from the Setec power supply from the mains. There is an input from the trailer plug to supply your lighting from the tugs battery. There are 3 different plugs to connect to the tug dependent on the state your van was ordered and delivered. These battery feeds are of a light weight size and really not suitable for battery charging, they are just meant for providing lighting on occasional use. Does your tug supply lighting without the battery being there? The standard wiring to a trailer socket on a tug does not generally provide for 12 V power to the van unless you ask for it.

The Setec PSU is touted to be a battery charger. It does provide trickle charging to maintain a well charged battery but will not charge a battery in a timely manner. The feed into the Setec from the tug is routed through a diode so that any battery in your van will nor feed back into the tugs electrical system and discharge the van battery. This diode reduces the voltage available to charge the battery.

I have presented the above to show how the average van requires special consideration when it comes to running battery systems in vans. To charge a van battery from the tugs alternator requires very heavy cable and substantial plug/socket connectors. The 7 or 12 pin connectors are too small to accommodate cable of sufficient size to directly charge a battery. . If you use a battery booster (DC - DC charger) then it is possible to to run the battery supply through the large plugs used in Vic, SA and Tas (however you will have to use short lengths of smaller cable to join the ends of the heavy cable to the plug/socket pins.) If your van is a standard Jayco it will not have have this heavy wiring in it.

KerryandBruce · Veteran Member

No, nothing blown. From all of the replies, we have come to the conclusion that the fridge is drawing too much power. Will now settle for a 2 KVA honda generator.

Thanks again for replies.

-- Edited by KerryandBruce on Tuesday 17th of July 2012 06:24:54 PM

KerryandBruce · Veteran Member

rockylizard wrote:
Gday...
I had mine checked out because it appeared that the car was not charging the battery when driving.
The autoelec found there was nothing wrong and all was as it should be.
His advice was that, when driving to charge a van battery, it takes twice as long for the car's alternator to restore the battery as it took to use it - eg use it for two hours last night, need to drive for at least four hours the next day to get it back to "full". I very rarely drive for four hours uninterrupted and rarely that long in a day.
Hence, I got solar panels, they charge ALL the time (as long as there is sun - or very little cloud) driving or not.
Cheers - John

-- Edited by rockylizard on Monday 16th of July 2012 08:22:24 PM

Thanks for that John. We have been contemplating solar but still hesitatant. Are you happy with your decision and how many panels do you have?

So much to learn and so many things to buy sheesh. All good fun but eh.

Nicholstones · Guru

Are you running the fridge on DC while travelling? In that case, the battery may be being charged from the vehicle, but the power being drawn for the fridge exceeds the charge coming in.

rockylizard · Guru

KerryandBruce wrote:
Thanks for that John. We have been contemplating solar but still hesitatant. Are you happy with your decision and how many panels do you have?
Gday...
I have two 80watt panels on the roof which were charging into a 100Ah battery. This was coping very well with my lifestyle. I only run 12v lights and charge my laptop and mobile through a 180W inverter from the van battery when camped.
Often I charge the laptop and mobile in the car while driving, again through the inverter. I run the fridge on gas when camped.
Since installing the solar panels back in Jan this year, I have not used the generator once.
The 100Ah battery (3 years old) died about two months ago and I replaced it with a 120Ah battery which should give me plenty of power for what I need.

Cheers - John

KerryandBruce · Veteran Member

Please, what is a DC-DC charger? :)

KerryandBruce · Veteran Member

We have Anderson plugs and 6ml cable from the car to van. It's parallel to the battery and runs a fridge. Van is Jayco Freedom pop top.

Peter, our van does have heavy wiring to both fridge and battery.

aussietraveller · Guru

Mine has a fairly substantial fuse and I believe all battery charging systems should have one probably located in the tug somewhere, it might be worth checking to see if the fuse has blown

rockylizard · Guru

KerryandBruce wrote:
No, nothing blown. From all of the replies, we have come to the conclusion that the fridge is drawing too much power. Will now settle for a 2 KVA honda generator.
Thanks again for replies.

Gday...

From your comment above,I assume you run the fridge on 12v when camping?

Is that because it does not run on gas?

Cheers - John

justcruisin01 · Guru

KerryandBruce wrote:
Can you tell me if the caravan batteries are meant to be recharged while driving? Thought they did but ours doesn't and we don't know why? Don't really want to spend every 3rd night at a caravan park if we don't need to.

Reguardless of wetheryou have a wiring circut to your van or not , even a heavy duty wire you CANNOT charge a van battery direct from the car system.

There is NOT enough voltage in the system to carry power that & do the job required. You may get a small amount of charge, but if you are running the van fridge as well on 12volt then it will never charge.

The newer the car the worse the problem is due to every thing being controled by a computor.

The ONLY successful way to charge the van battery FULLY from the car alternator is a DC_DC charger as stated ealier. At around $500 its still cheaper than solar.

This topic has been on here many times & any one who thinks they can fully charge van from car is having them selves on.

Even in the new cars a accessory battery in the back of the vehicle needs a DC_DC to work.

The computor systems sets the voltage at one constant level, due to the fact that electronics do not like veriations &/or spikes in voltage, there fore the required voltage to get to the rear located systems is to low.

To take the point a step further,in some new cars IF you were to replace the starter battery with a larger on, as in more amp/hr capicity the computor does not reconise it & wont charge at all.

Car builder are NOT interested in what we want to do with a tug, Its system is just to maintain its self & nothing more.

JC.

billeeeeeee · Guru

justcruisin01 wrote:
KerryandBruce wrote:
Can you tell me if the caravan batteries are meant to be recharged while driving? Thought they did but ours doesn't and we don't know why? Don't really want to spend every 3rd night at a caravan park if we don't need to.

Reguardless of wetheryou have a wiring circut to your van or not , even a heavy duty wire you CANNOT charge a van battery direct from the car system.
There is NOT enough voltage in the system to carry power that & do the job required. You may get a small amount of charge, but if you are running the van fridge as well on 12volt then it will never charge.
The newer the car the worse the problem is due to every thing being controled by a computor.
The ONLY successful way to charge the van battery FULLY from the car alternator is a DC_DC charger as stated ealier. At around $500 its still cheaper than solar.
This topic has been on here many times & any one who thinks they can fully charge van from car is having them selves on.
Even in the new cars a accessory battery in the back of the vehicle needs a DC_DC to work.
The computor systems sets the voltage at one constant level, due to the fact that electronics do not like veriations &/or spikes in voltage, there fore the required voltage to get to the rear located systems is to low.
To take the point a step further,in some new cars IF you were to replace the starter battery with a larger on, as in more amp/hr capicity the computor does not reconise it & wont charge at all.
Car builder are NOT interested in what we want to do with a tug, Its system is just to maintain its self & nothing more.
JC.

Bugger............

PeterD · Guru

KerryandBruce wrote:

Please, what is a DC-DC charger? :)

I see no one has bothered to answer this yet.

When batteries in an engine compartment heat up with the temperature under that bonnet their charge requirements change. A hot battery needs less voltage to charge it than when it was cold. Conversely, when a battery heats up, if you don't reduce the applied voltage from the alternator you will overcharge that battery. To prevent this possible overcharging alternators have temperature compensation built into them. As temperature rises the alternator voltage drops. A hot alternator will have an output of 13.75 V or less. Some vehicles like the Hilux have been measured at around 13.2 V. The problem with your vans battery is it is still cold and needs a higher voltage to charge it.

To charge a van battery in a timely manner we use a battery booster, DC - DC charger, DC charger or any other name you choose to call it. These devices are a bit like having a mains operated multi stage charger and feeding it with 240 V from an inverter fed by 12 V from your tugs alternator. The DC - DC charger does the conversion in one box and not two. One of the problems of driving a battery charger from an alternator is you loose power twice, firstly in the inverter and secondly in the charger. The DC - DC charger does it once in the one box so is way more efficient

When I first looked into these boosters 25 years ago there was only one model featured in Oz. Now there are many models on the market. Some are just DC chargers in the box. Others include solar regulators and there are others which have the battery booster, solar regulator and mains charger in the one box.

For more reading try these links:

http://www.australiandirect.com.au/shop/power-electrical/battery-accessories/dc-dc-chargers/120405

http://www.batteriesdirect.com.au/shop/product/9602/dc20.html

http://www.baintech.com.au/chargers/sterling-dc-to-dc-charger-12v-12v

http://www.sidewinder.com.au/page168aa.html

http://www.kulkyne.com/au/DC-Battery-Chargers/?gclid=CO-3uMzioLECFUKDpAoduivbRg

wasn_me · Guru

An excellent simple diagram. Much easier than trying to explain to somebody what to do. Thanks, Rockylizard for posting it. Is the wiring size refered to in the diagram, what is usually bought as 6mm?

Pete

03_troopy · Guru

The wire in the diagram is 6B&S or 6AWG, which is equal to 13.3mm sq CCA (circular cross-sectional area of conductor) When you ask for 6mm wire you may end up with either 6mm auto wire or 6mm sqare cca depending on where you buy it. I think 6mm auto wire is about 4.6mm sq cca.

Roving-Dutchy · Guru

There is also a DC to DC charger available from Super Cheap cost approx $100 when on special $80 it is only a 10 amp charger this may do the job, I use one in my van but I don't have a large drawdown as it is mainly used for lighting which is all Leds and with about 3 hours driving brings the battery back up to full charge.
I also replaced all the 12v wiring from the tug to the fridge and battery with 6B&S.
Cheers
David