Interesting thread - I'm planning to add a panel to my setup eventually, and the one linked above looks a good price. Can you tell me about the junction box on the panel itself?
I have a 'CTEK D250S Dual' battery-to-battery charger that has a built in MPPT regulator, so all I need to do is connect the panel directly to the posts on that I believe. Will I be able to open the junction box to replace the MC4 pigtails with my own direct cables? The photo in the eBay listing* shows the connectors inside the junction box, but that photo suggests that the surface of the panel was damaged around the junction box on that particular unit - was that caused by opening the junction box perhaps?
And is there something special about 'solar' cable, or will any cable that can cope with at least 10A be suitable for a 100W panel? Do they just call them 'solar' cables when they've got MC4 connectors on the end?
*E D I T: This is the photo I was referring to, from the advert Tom linked to:
"I'm a man of means, by no means....King of the Road!"
CJH wrote:Interesting thread - I'm planning to add a panel to my setup eventually, and the one linked above looks a good price. Can you tell me about the junction box on the panel itself?
I have a 'CTEK D250S Dual' battery-to-battery charger that has a built in MPPT regulator, so all I need to do is connect the panel directly to the posts on that I believe. Will I be able to open the junction box to replace the MC4 pigtails with my own direct cables? The photo in the eBay listing* shows the connectors inside the junction box, but that photo suggests that the surface of the panel was damaged around the junction box on that particular unit - was that caused by opening the junction box perhaps?
And is there something special about 'solar' cable, or will any cable that can cope with at least 10A be suitable for a 100W panel? Do they just call them 'solar' cables when they've got MC4 connectors on the end?
*E D I T: This is the photo I was referring to, from the advert Tom linked to:
On my panel the junction box doesn't look/feel like it will come apart. I think it is glued on. The panel comes with about 1m lengths of 4mm solar cable with MC4 connectors. As I want to run these cables through 6mm grommets I have disconnected the MC4 connectors. They can be undone with 2 pairs of pump pliers, be careful as the threads look like they were glued. The tricky bit is releasing the terminal from the housing. I used slivers of a beer can rolled into a cone shape and slide them around the connection. Took a while but they are now in pieces and will easily go back together. The reason I didn't just cut them of was I was concerned it would void the warranty.
AFAIK Solar cable is just double insulated cable.
I have a B2B sterling charger, I don't know how similar this is to what you have. I was thinking that I would connect the solar controller to the starter battery which would in turn charge the leisure batteries. This would also give the benefit of monitoring the charge rates through the remote control. The issue doing it this way is the Sterling charger needs a certain amount of power to operate, which is fine when using a high power source like an alternator but will greatly reduce the efficiency of the solar panel.
Ah yes, double insulated - that makes sense. Is that 4mm the outside diameter or is it 4mm2 cross section area of the conductor? If the latter, that's going to be good for 30-40 amps.
I might ask the seller about alternatives to those 90cm MC4 pigtails - even if you're planning to keep them (as I assume you are), and even if the cables are long enough, you're still going to need to get them through grommets into the inside of the van, so they don't seem like the most convenient connectors. If I can get into the junction box I'll probably use 2-core flex - that'll be double insulated and it'll be a single cable that needs to get into the interior.
I've only fitted the CTEK system today so I'm still learning about it, but it seems to use DC sources other than the alternator to prioritise the leisure battery, and once that's fully charged it will use surplus power to pulse charge the starter battery. Since the MPPT controller is built in I don't really have a choice as to which battery it connects to. Does your Sterling allow DC sources to connect to either battery, or does it always go from starter battery to leisure battery?
"I'm a man of means, by no means....King of the Road!"
ScienceBoy wrote:How do you wire this together with a Zig so there's dual battery charging from the pv panel AND from the alternator?
Good question. Until I fitted my CTEK system over the last couple of days I had a Smartcom smart relay for my split charging system. It's a voltage sensing relay - once it detects a charging voltage being applied to the starter battery it closes the relay so that that charging voltage reaches the leisure battery too. I suppose if the solar panel provides a similar voltage then the relay will close and the solar charge will reach both batteries in parallel. The drawback with this approach is that this will link both batteries whenever there is enough sunshine, e.g. while you're parked up on a campsite, and if you then run enough DC consumers to use more current than the panel is supplying, then you'll be depleting the starter battery as well as the leisure battery.
So I'm not sure. Hopefully someone with more experience will chime in. I suspect you can get solar regulators that have two outputs. That would work independently of your Zig.
E D I T: D'Oh! the controllers linked elsewhere in this thread are for two batteries.
"I'm a man of means, by no means....King of the Road!"
My solar panel doesn't go via the zig it goes straight into each battery (dual regulator/charger), unless someone thinks I should I connect it differently?
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2015 California Beach
MattBW wrote:My solar panel doesn't go via the zig it goes straight into each battery (dual regulator/charger), unless someone thinks I should I connect it differently?
We've just bitten the bullet and purchased a Waeco CR50 so this will be the next addition after the Sterling B2B 50amp. Hopefully by the time we get to S of France in June!
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PetenAli wrote:Really helpful thread - thanks all.
We've just bitten the bullet and purchased a Waeco CR50 so this will be the next addition after the Sterling B2B 50amp. Hopefully by the time we get to S of France in June!
Same set up as we have.
The CR50 is a fantastic but it quite power hungry. I hoping the 100w panel with add a day or two to the batteries before needing to start the engine and letting the B2B charger do its thing.
Been reading this for a while now to see how it develops.
I am no solar guru but what I can say is that a solar set up will not noticeably charge a decent battery bank up and if your running a compressor fridge and ebber you will need a charging system. What a solar set up will do is give you a good trickle charge and thats good for battery health in my limited experience. My 40w solar set up will run the compressor fridge using all the solar trickle during a sunny day but will need the battery bank during the night time and so will my ebber. This means I will need the batteries charging every 4 or 5 days still. I use a Sterling with the engine running for a few hours or you could use a 240 hook up with a decent 240 charging system.
jed the spread wrote:My 40w solar set up will run the compressor fridge using all the solar trickle during a sunny day but will need the battery bank during the night time and so will my ebber.
Yeah, when are they going to come out with Lunar chargers?
Your 'limited experience' beats my 'no experience', but isn't the difference between a 40W panel and a 100W panel significant? A 40W panel is going to provide less than 3A of 14.5V charging current, which is indeed trickle charge territory, and a controller that just burns off the excess voltage will waste some of that (that's not a dig at your controller - I have no idea what you're using), whereas a 100W panel, at full tilt on an MPPT controller can in theory provide nearer 7A, and that takes it much closer to a mains charger. Certainly it's going to need a sunny day, but 5 hours of sunshine would give 35AH, which would fully recharge a half empty leisure battery. I know that's just theoretical, and I have no idea how well they work in practice, but there have been several reports on here of leisure batteries being topped up quite nicely by a big solar panel. But of course, days with plenty of bright sunshine don't necessarily go hand in hand with nights that need Eberspachers running....
"I'm a man of means, by no means....King of the Road!"
