Charge both Leisure and Engine starter battery from solar

kave

kave

Messages
1,632
Location
Boras Sweden
Vehicle
T6 Beach 4Motion
I have just ordered a dual panel setup from Roger here on the forum.
A friend of mine who is an electrician and who drives a VW Transporter with a “leisure” battery installed for tool work, ie they have compressors etc used from the van when working. When they use stuff that takes lots of amps they have a switch so they can connect the leisure and engine starter battery while the engine is running to force the generator to charge both batteries at once. Whould it be a good idea to connect both batteries while a solar panel charges them? I have understood that many people here advice against connecting two battery types to charge them at the same time?
 
I know but I rather get the Victron charger. Apparently this is how the van charges the leisure battery, it does not switch charging between starter and leisure battery, it just connects the leisure battery to the charging circuit when the engine battery is full.
 
You are exactly right. When the engine is running, a relay links the leisure battery and starter battery, so they charge at the same time. This is classically known a a split charging relay system.

Sometimes there is a slightly more complicated solution where a DC-DC charger is used- basically a charger that uses the starter battery to charge the leisure battery with any excess current.

If you want to use the solar setup to charge your starter, there is no reason you can't have a switch to link the two batteries - just make sure the cable is up to the job, as any significant voltage difference will result in huge (50+) amps being sent down the wire. Also, if you forget to switch it off, then you run the risk of flattening both batteries when camping, and then can't start the van.

Another solution (which I employed in my old camper) is to put the battery charging live wire from the solar regulator through a single pole 2-way switch - one pole goes ot the leisure battery, the other to the starter. Flick the switch and you flip between charging one or the other, with no risks of the above setup, and no need for a massive wire.
 
I have no knowledge of the smart pass, but there is a solar regulator that charges both batteries - the Western Co. WRM15 - I sell it.
 
I just measured my starter battery yesterday, 12.2V so it seems I need to charge it manually.
The leisure battery was at 12.7 so it seems that gets charged fine by the alternator.
I think I will try to get a manual switch to switch charging between the batteries.
Or I will go with your option. Can you connect alll this from under the left seat where the solar goes to the leisure battery? I guess there is also cables to th starter battery there?
I think all Beaches should be equipped with this battery to battery charger since the mains charger won’t charge the starter battery
 
Last edited:
sorry if this is a silly question, but why would I want to charge my starter battery with solar?

surely that's the alternator's job?

never needed extra charging in any of my cars
 
kp64zl said:
sorry if this is a silly question, but why would I want to charge my starter battery with solar?

surely that's the alternator's job?

never needed extra charging in any of my cars
Click to expand...
Lets say you camp for a few days without hookup, you play the radio for a couple of hours each day, you open and close doors many times, you use the reading lights in the front, you leave the tailgate open, you charge your ipad or phone from the 12v dash socket every day.
Day 4 your starter battery is flat because all of the aforementioned will use the starter battery ...and bearing in mind your starter battery may only be at 80% charge when you stopped, it may only last 2 days.
 
kp64zl said:
sorry if this is a silly question, but why would I want to charge my starter battery with solar?

surely that's the alternator's job?

never needed extra charging in any of my cars
Click to expand...

I guess you've never camped for any duration in any of your "cars"?
 
kp64zl said:
sorry if this is a silly question, but why would I want to charge my starter battery with solar?

surely that's the alternator's job?

never needed extra charging in any of my cars
Click to expand...
I would recommend measuring your batteries with a voltmeter. If they are 12.7V or higher they are full and they will work fine and have a long life. If its is like mine, 12.2V it is severely depleted and obviously is not fully charged from the alternator in our driving pattern. I was thinking it should be charged on hookup but obviously not. The charging of the starter battery from the installed solar panels will hopefully make this a non issue.
 
kave said:
I just measured my starter battery yesterday, 12.2V so it seems I need to charge it manually.
The leisure battery was at 12.7 so it seems that gets charged fine by the alternator.
I think I will try to get a manual switch to switch charging between the batteries.
Or I will go with your option. Can you connect alll this from under the left seat where the solar goes to the leisure battery? I guess there is also cables to th starter battery there?
I think all Beaches should be equipped with this battery to battery charger since the mains charger won’t charge the starter battery
Click to expand...

If you want to put a switch inline, then it needs to be somewhere before the batteries "split".

With a Cali Ocean, you could put the switch by the solar regulator (top cupboard), then run one battery live down to the battery in the back, and the other under the trim up to the relay under the passenger seat (that connects to the starter battery).

You could also run just one cable to the passenger seat, put the switch there, then send one wire from it to the battery under the seat, and the other to the relay (for the starter). This would charge both LBs as they are linked.

Personally, I'd put the switch in the back to keep the most important cable run (to the Leisure battery) as short as possible to reduce voltage loss.

And SPDT switch woudl do. Such as https://www.ebay.co.uk/itm/191522646684

Most people don't need to charge their starter battery. The cases where people buy dual chargers are usually when they park up the van for long periods without use, and want to protect their starter battery from gradual drain. I put the switch in my camper just because it covered emergency eventualities, and adding a switch was a no cost option so I did it for the hell of it. Never used it mind you :)
 
kave said:
I have just ordered a dual panel setup from Roger here on the forum.
A friend of mine who is an electrician and who drives a VW Transporter with a “leisure” battery installed for tool work, ie they have compressors etc used from the van when working. When they use stuff that takes lots of amps they have a switch so they can connect the leisure and engine starter battery while the engine is running to force the generator to charge both batteries at once. Whould it be a good idea to connect both batteries while a solar panel charges them? I have understood that many people here advice against connecting two battery types to charge them at the same time?
Click to expand...
Thanks to Roger Donoghue I have the Victron charger. With the step by step installation instruction for dummies (ie me!) it was easy to fit. I check the battery charge daily so see no need for a connection to the starter battery. I now have 30 metres of cable and connectors that are redundant; thanks Roger!
 
kave said:
I would recommend measuring your batteries with a voltmeter. If they are 12.7V or higher they are full and they will work fine and have a long life. If its is like mine, 12.2V it is severely depleted and obviously is not fully charged from the alternator in our driving pattern. I was thinking it should be charged on hookup but obviously not. The charging of the starter battery from the installed solar panels will hopefully make this a non issue.
Click to expand...
If your Engine Battery is measured at 12.2 v the there is something seriously amiss.
After 4 weeks parked up with Alarm On my Engine Battery was still at 12.5v and the Engine started at first attempt with ambient temperature significantly less than 0c.

If your vehicle Does Not Charge the Engine Battery On Mains Hookup, as you claim, and the Engine Battery is measured at 12.2v then connecting a Solar Panel to the Battery is just treating the symptoms of what could be a significant problem in the future.
 
In my 2017 T6 (delivered with second batterie and cut-off relay from factory)

I put this solar panel on the roof:

https://www.bluepowershop.nl/victron-solar-panel-190w-24v-mono.html

Combined with this charge contoller with bluetooth:

https://www.sunstore.co.uk/product/victron-smartsolar-mppt-100-20/

And I changed the original cut-off relay with a Cyrix-ct 12/24V 120 A relay (attachement).


With this configuration I have the comfort of 2 batteries while camping
but with the knowledge that I always can start the engine.
 

Attachments

  • Datasheet-Cyrix-ct-120A-230A-EN.pdf
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I just ordered a kit from roger, website seems easy to follow, order and very informative I went for a single panel and the Weston co WGM15.

I figured I didnt need the dual panel arrangement and maximum power as we don't run anything extra in the van beyond the standard kit of fridge, lights, the radio and charging phones. It's also a factor that the mains socket only works when you're on mains hookup anyway, so no point having more power when we have no access to hookup.

I did want the ability to charge all the batteries though and cycle them, hence the choice of the WGM15.

I'll feed back once the kit is fitted.
 
The kit should be with you on Tuesday brian :)
 
kave said:
I have just ordered a dual panel setup from Roger here on the forum.
A friend of mine who is an electrician and who drives a VW Transporter with a “leisure” battery installed for tool work, ie they have compressors etc used from the van when working. When they use stuff that takes lots of amps they have a switch so they can connect the leisure and engine starter battery while the engine is running to force the generator to charge both batteries at once. Whould it be a good idea to connect both batteries while a solar panel charges them? I have understood that many people here advice against connecting two battery types to charge them at the same time?
Click to expand...
Hello, I’d like also to install solar panels on my Ocean. Could you please advice how I should proceed to get them from Roger? Many thanks.
 
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