# Solar Power charging vehicle battery?



## Beemer (Mar 7, 2011)

Have purchased a 100w solar panel with 10A charge controller off ebay to top up leisure battery.
My question is could I also use the same panel to top up my vehicle battery when it is stood unused?
My idea would be to fit an inline switch  (CBE UNIPOLAR + LED 12V SWITCH motorhome caravan boat on eBay (end time 14-Mar-11 14:53:45 GMT) ) off the battery connections of the charge controller, so that I may choose when to transfer some of the supply generated by the solar panel.

We will be using a campsite near Bordeaux for 10 days, using their ehu, but don't want the vehicle battery to lose charge during the stay.

Open to other/better ideas or considerations if any? ...thanks


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## Neckender (Mar 7, 2011)

I have just brought from CAK tanks, a battery master £25 three wires one to leisure battery one to cab battery and one to earth. It charges leisure first and then cab battery. also if you have alarm and vehicle battery starts to drain, it automatically takes some of the drain from leisure so cab battery doesn't run down so quick.

John.


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## Canalsman (Mar 7, 2011)

Beemer said:


> We will be using a campsite near Bordeaux for 10 days, using their ehu, but don't want the vehicle battery to lose charge during the stay.


 
If the vehicle battery won't start your van after standing for 10 days - it's knackered!

Get a new battery before you go ...


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## maingate (Mar 7, 2011)

There are different ways to do it but Trikermans suggestion is by far the easiest and foolproof method.

For any European van with an Electroblock unit, the solar panel can be connected to it and it will charge both batteries.


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## David & Ann (Mar 7, 2011)

I don't know about you folks, but we have 120w, 2 x 60w panels. When we travel for the summer from April to September (4 to 5 months) in Spain and Portugal every year, we have never ever plugged into the mains as we only wild camp. We have 3 x 110AH habitation batteries + 110AH starter battery. I check them daily and they are always fully charged. Once we arrive on the coast, we do not drive long distances, but from beach to beach. I expect the sun does all the charging up that we need.


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## Beemer (Mar 7, 2011)

trikerman said:


> I have just brought from CAK tanks, a battery master £25 three wires one to leisure battery one to cab battery and one to earth. It charges leisure first and then cab battery. also if you have alarm and vehicle battery starts to drain, it automatically takes some of the drain from leisure so cab battery doesn't run down so quick.
> 
> John.



Sounds like just the job...thanks trikerman.
Hopefully, the vehicle battery won't have drained after 10 days, but I really don't want to take the chance, hence the intended conversion.


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## bevdrew (Mar 8, 2011)

Fitting a bridging fuse between leisure and vehicle batteries would be a cheaper option than buying a battery master. See how to do this, on this web page:

Fitting a Bridging Fuse

Bev


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## rickboy (Mar 8, 2011)

*Maplins split charge module*



Beemer said:


> Have purchased a 100w solar panel with 10A charge controller off ebay to top up leisure battery.
> My question is could I also use the same panel to top up my vehicle battery when it is stood unused?
> My idea would be to fit an inline switch  (CBE UNIPOLAR + LED 12V SWITCH motorhome caravan boat on eBay (end time 14-Mar-11 14:53:45 GMT) ) off the battery connections of the charge controller, so that I may choose when to transfer some of the supply generated by the solar panel.
> 
> ...



Take a look at Maplins N73AU about £10.. Just be aware its only rated up to 8amps continuous so don't hit it with alternator or large amp charger.


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## Beemer (Mar 8, 2011)

bevdrew said:


> Fitting a bridging fuse between leisure and vehicle batteries would be a cheaper option than buying a battery master. See how to do this, on this web page:
> 
> Fitting a Bridging Fuse
> 
> Bev



I like that too.  I could use a fused switch to achieve the same effect, and it would neater and more like it should be 'there'.
Thanks Bev


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## maingate (Mar 8, 2011)

Beemer said:


> I like that too. I could use a fused switch to achieve the same effect, and it would neater and more like it should be 'there'.
> Thanks Bev


 
As long as you remember to carry spare fuses.


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## DRS (Mar 8, 2011)

I have a 110AH leisure battery but the vehicle battery is a 95AH so this would mean that the leisure battery would never charge to it's full capacity.


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## David & Ann (Mar 8, 2011)

If the 95AH is your starter battery, it should be okay, as it is charged by the alternator while you are driving.


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## Beemer (Mar 14, 2011)

I have now fitted all the wiring and connected the charging control regulator to my leisure battery.
It is all but complete, I am just waiting for two solar cable connectors to come via ebay and then I can wire up and fix the solar panel onto the 'van roof.
I have not however wired up the vehicle battery to the regulator yet, as I am not sure about what control system to use.  I have seen this one on ebay, but it does not say if it can be fitted to a leisure battery and a vehicle starter battery.
What does the team think?
2 WAY SOLAR SPLIT CHARGE RELAY - 6-24V - 20A on eBay (end time 19-Mar-11 14:59:04 GMT)
I am concerned that the initial start up voltages/amps may damage my new system.
Thanks
Dave


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## Canalsman (Mar 15, 2011)

That device looks fine to me - the only stipulation is that you have regulator in the circuit before this module. (So you'll need to rejig your wiring slightly - solar panel  -> regulator -> split charge relay -> leisure battery and starter battery.)

You have 12v starter and leisure batteries, and so long as they're lead acid construction this should do the job.


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## Beemer (Mar 17, 2011)

Canalsman said:


> That device looks fine to me - the only stipulation is that you have regulator in the circuit before this module. (So you'll need to rejig your wiring slightly - solar panel  -> regulator -> split charge relay -> leisure battery and starter battery.)
> 
> You have 12v starter and leisure batteries, and so long as they're lead acid construction this should do the job.



Thank you Canalsman, I can place the split charge relay after the regulator, as I have left enough space for this.


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## maingate (Mar 17, 2011)

If it is an Electrobloc unit (I am fairly certain it will be) then it puts a float charge of about 2 amps into the vehicle battery and the bulk of the charge into the leisure batteries (16 to 18 amps typically)

Easy to find out, put a multimeter across the van battery to get the voltage, then hook up van and recheck the voltage. It should be higher.


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## Tony Lee (Mar 18, 2011)

While connecting the leisure battery to the engine battery with a switch or fused link will work, it is a very crude solution in that it relies on the user to disconnect the system when it is not required. This may not be a problem if it is only done when laying the vehicle up for a long time, but even then, does run the risk of phantom loads in the house running the starter battery flat. If it is left connected when camping, then flat batteries all-round are pretty much inevitable. 

There are several ways to do it

I use several Schottkie (Sp??) diodes (each with a series 1 Ohm current-limiting/balancing resistor) in parallel to feed from the house to the starter batteries in one vehicle. This does have the disadvantage that a fault on the engine battery side could leave all batteries flat. A duo-charge solar regulator charges both batteries alternately in another vehicle and is failrly foolproof. Another has a Triklecharge (Sp??) unit that allows up to 5 amp charge from the house system to the engine system - provided the house sysytem is fully charged - and is also fairly well protected. The Hobby has the solar regulatoe feeding into the charging system which allows a trickle charge into the engine battery.


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## Kontiki (Mar 22, 2011)

I used the bridging fuse idea, I also wired an old voltmeter in the circuit which is mounted next to my solar regulator. I also fitted a small red LED so it stands out when connected.


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## Beemer (Mar 31, 2011)

Have got one of these off ebay now, so that should solve any problems I may have.
CHARGER, (LEISURE & ENGINE BATTERY), SOLAR BOAT CAMPER on eBay (end time 08-Apr-11 16:35:25 BST)


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