Solar Isolator

[Pudsey Bear]

I was impressed with my 4a + out of a 85w panel, quite old but a good make & covered in garage dust and crud, I may get upto 5a on a good day so poss 10a with two up there maybe.

 

[wildebus]

I put a household 230vac 13A Fused DP switched fused spur in to isolate the solar, my solar will never exceed 13amps. I guess this may technically be wrong in some way!
But the only reason I 'had' to do this was the the Renogy B2B/solar 30amp has a quirk in that if it receives both a solar and B2B charge input then it limits each one to 15 amps. So when there is say 1Amp of solar and I'm driving my max charge is 15+1 amp total. When I turn of solar then B2B will supply 30A Charge. The one annoying thing about this Renogy B2B/Solar equipment.

You could use a 5-pin relay instead. connect the PV to pin 87a, the solar input to the renogy to pin 30, pin 85 to ground and pin 86 to either a D+ or an Ignition signal. Then you wouldn't have to remember to flick the switch over when driving, and then back again when stopped.
Using a 5-pin relay and 87a (NC) pin means that when the solar is active, the relay is not using any power.
And doing this would likely be cheaper than using a DP fused spur as well. Win-Win

 

[The Borg]

This is my set up with Isolator

bottom right hand corner

 

[Robmac]

This is my set up with IsolatorView attachment 140650 bottom right hand corner

And a very neat setup it is too.

 

[Pudsey Bear]

Overkill I think for us, not keen on coiled mains cable, I'd shorten that.

2x85w on a good day can only give me approx 10a, so a double pole 20a switch should be fine, not pretty I grant you, and it may even arc but it will be brief (I think) and encased with nothing volatile nearby.

My biggest concern is getting these bloody great 6mm2 cables in, pliers will be needed to pre-bend them

 

[wildebus]

Overkill I think for us, not keen on coiled mains cable, I'd shorten that.

2x85w on a good day can only give me approx 10a, so a double pole 20a switch should be fine, not pretty I grant you, and it may even arc but it will be brief (I think) and encased with nothing volatile nearby.

My biggest concern is getting these bloody great 6mm2 cables in, pliers will be needed to pre-bend them

for your PV Array size, you could easily just snip off a fair number of strands off the 6mm cable and put the remainder into the terminal of the switch you are fitting. Just make sure you don't leave any stands floating around exposed!

 

[Pudsey Bear]

I have some yellow pin terminals but not sure if I'll.be able to use them, patress is 45mm deep so I'll have to see.

 

[yeoblade]

You could use a 5-pin relay instead. connect the PV to pin 87a, the solar input to the renogy to pin 30, pin 85 to ground and pin 86 to either a D+ or an Ignition signal. Then you wouldn't have to remember to flick the switch over when driving, and then back again when stopped.
Using a 5-pin relay and 87a (NC) pin means that when the solar is active, the relay is not using any power.
And doing this would likely be cheaper than using a DP fused spur as well. Win-Win

That's a great idea , I've a relay in my 'box of bits' if I can trigger it using a B2B active signal rather than trying to find the D+ even easier, Ill have a look

 

[wildebus]

That's a great idea , I've a relay in my 'box of bits' if I can trigger it using a B2B active signal rather than trying to find the D+ even easier, Ill have a look

make sure it is the 5 pin 'changeover' relay. a standard 4 pin relay would not really be suitable

 

[gasgas]

You seem to be implying that driving when the solar is connected, is a bad thing. I thought that panels have a built in diode preventing reverse current?
Personally if I want to fiddle with batteries I just undo the +ve wire from the solar regulator. I sometimes even remember to replace it afterwards, when I have traced the source of the dim lights by measuring the battery voltage as 10v.

 

[wildebus]

You seem to be implying that driving when the solar is connected, is a bad thing. I thought that panels have a built in diode preventing reverse current?
Personally if I want to fiddle with batteries I just undo the +ve wire from the solar regulator. I sometimes even remember to replace it afterwards, when I have traced the source of the dim lights by measuring the battery voltage as 10v.

did you read the post where he explained the situation?
He is saying it is a bad thing to have the solar active when driving as he could lose nearly half the total possible B2B output due to the way the Renogy B2B/MPPT Combo is designed.
Not rocket science to want to stop that happening having by disconnected the solar.

 

[Geek]

Hi
Can someone suggest whether or not I need a solar isolator between my 2x110 watt panels and my Victron MPPT regulator?
Thanks

No

 

[gasgas]

did you read the post where he explained the situation?
Beg your pardon, sorry obviously I didn't. As I have an old clonker with a moronic alternator that only puts volts out when it sees a demand, I haven't got entangled with intelligent alternators. . . . . . .
But I have just discovered a THING about solar panels, and intelligent isolators.
I bought an 'intelligent isolator' and fitted it. Not this exact one, but probably the only difference is the label on the front:

Split Charge Relay 12V 140A 140 AMP 0-727-33 Portable Power Voltage Sensitive | eBay

RV Window 500x300mm Horizontal Slide Camper Window Waterproof Round Corner. Note: The benefit of this type of relay is that it does not require a connection to the alternator or any modifications to the existing vehicle electrical system.

www.ebay.co.uk

This is a reeeeeeeeeely clevvver device which would replace the changeover relay in a car/caravan combo or a motorhome without a solar panel. It sends engine volts to the LB when the alternator is producing its proper output. I have been fitting two Lifpo batteries and a Renogy inverter. I have an Epever regulator with two outputs, EB and LB. I finished hooking everything up and it all worked fine, the LBs were at 13.5v in the sunshine. The Epever was showing 13.6v output. Fair enough. However, I noticed that without the engine running, the inteligent isolator LED was on, indicating that the EB was connected to the hab wiring and therefore the LB as well. Thinking I had done some incorrect wiring I had a cup of tea and a biscuit and sat and looked at it for a while. Then I realised that the solar output was triggering the isolator because the panel was charging the EB, which was now at 13.5v and therefore triggering the isolator.
So the question is - do I rip out the intelligent isolator and replace it with the normal changeover relay, or just leave it connecting the two LBs to the EB, until their volts drop to 12.8v?
I think I know the answer. Another waste of £20, just like the other assorted glitzy things that look good on ebay / temu /amazon and so on. I've got plenty of 20A relays in the man shed. More wiring . . . .harrumph. I'll be soldering several of their pins in parallel. I don't trust these little plastic relays, having been brought up with GPO 2000 type relays with Platinum contacts. I'll need several relays - if the alternator can chuck out 95A then I don't want some poxy 10A relay contacts getting in between the alternator and two 100AH Lifpo batteries, not to mention that something in the hab area might be turned on . . .

 

[mistericeman]

did you read the post where he explained the situation?
Beg your pardon, sorry obviously I didn't. As I have an old clonker with a moronic alternator that only puts volts out when it sees a demand, I haven't got entangled with intelligent alternators. . . . . . .
But I have just discovered a THING about solar panels, and intelligent isolators.
I bought an 'intelligent isolator' and fitted it. Not this exact one, but probably the only difference is the label on the front:

Split Charge Relay 12V 140A 140 AMP 0-727-33 Portable Power Voltage Sensitive | eBay

RV Window 500x300mm Horizontal Slide Camper Window Waterproof Round Corner. Note: The benefit of this type of relay is that it does not require a connection to the alternator or any modifications to the existing vehicle electrical system.

www.ebay.co.uk

This is a reeeeeeeeeely clevvver device which would replace the changeover relay in a car/caravan combo or a motorhome without a solar panel. It sends engine volts to the LB when the alternator is producing its proper output. I have been fitting two Lifpo batteries and a Renogy inverter. I have an Epever regulator with two outputs, EB and LB. I finished hooking everything up and it all worked fine, the LBs were at 13.5v in the sunshine. The Epever was showing 13.6v output. Fair enough. However, I noticed that without the engine running, the inteligent isolator LED was on, indicating that the EB was connected to the hab wiring and therefore the LB as well. Thinking I had done some incorrect wiring I had a cup of tea and a biscuit and sat and looked at it for a while. Then I realised that the solar output was triggering the isolator because the panel was charging the EB, which was now at 13.5v and therefore triggering the isolator.
So the question is - do I rip out the intelligent isolator and replace it with the normal changeover relay, or just leave it connecting the two LBs to the EB, until their volts drop to 12.8v?
I think I know the answer. Another waste of £20, just like the other assorted glitzy things that look good on ebay / temu /amazon and so on. I've got plenty of 20A relays in the man shed. More wiring . . . .harrumph. I'll be soldering several of their pins in parallel. I don't trust these little plastic relays, having been brought up with GPO 2000 type relays with Platinum contacts. I'll need several relays - if the alternator can chuck out 95A then I don't want some poxy 10A relay contacts getting in between the alternator and two 100AH Lifpo batteries, not to mention that something in the hab area might be turned on . . .

Most if not all VSR (Voltage sensing relays)
Are Bi directional ...

So will supply charge to the starter battery WHEN the leisure battery voltage is hi enough from solar/mains charging .

 

[wildebus]

out of interest ref these B2B/MPPT Combos ....
I have not come across the Renogy one before and how it operates. Have to say bit of a crappy design from what I have read here
Ablemail make a Combo - the AMS12-30-30 which has inputs from both. With that model, it uses a sense signal (typically from D+ or ignition) which will make it use the B2B inout solely; and without the signal present, it uses the the solar input.
Redarcs original BCDC combo charger worked in a similar way but you had to add in an external relay. Their newer one would use both inputs simultaneously, but in a clever way ... it would take all it could from solar and then make up the difference to the max output with power from the alternator - makes the most of the 'free' power.
There are a few others as well, but I can't remember the details of the charging methods.

However .... something you have to watch out for with these Combo chargers is the PV voltage ... It is generally a very low level and if exceeded will typically kill the charger! I have one of the Redarcs in my shed which is defunct after too high a voltage came in on the PV input. The best around in that respect is the Ablemail AMS - still limited to "12V" panels as the max voltage is 32V (higher than any others, mind) but if it is exceeded, it will cut out while the overvoltage exists and then work again when it drops - no damage is incurred.

Personally, I'd stick to seperates

 

[merl]

did you read the post where he explained the situation?
Beg your pardon, sorry obviously I didn't. As I have an old clonker with a moronic alternator that only puts volts out when it sees a demand, I haven't got entangled with intelligent alternators. . . . . . .
But I have just discovered a THING about solar panels, and intelligent isolators.
I bought an 'intelligent isolator' and fitted it. Not this exact one, but probably the only difference is the label on the front:

Split Charge Relay 12V 140A 140 AMP 0-727-33 Portable Power Voltage Sensitive | eBay

RV Window 500x300mm Horizontal Slide Camper Window Waterproof Round Corner. Note: The benefit of this type of relay is that it does not require a connection to the alternator or any modifications to the existing vehicle electrical system.

www.ebay.co.uk

This is a reeeeeeeeeely clevvver device which would replace the changeover relay in a car/caravan combo or a motorhome without a solar panel. It sends engine volts to the LB when the alternator is producing its proper output. I have been fitting two Lifpo batteries and a Renogy inverter. I have an Epever regulator with two outputs, EB and LB. I finished hooking everything up and it all worked fine, the LBs were at 13.5v in the sunshine. The Epever was showing 13.6v output. Fair enough. However, I noticed that without the engine running, the inteligent isolator LED was on, indicating that the EB was connected to the hab wiring and therefore the LB as well. Thinking I had done some incorrect wiring I had a cup of tea and a biscuit and sat and looked at it for a while. Then I realised that the solar output was triggering the isolator because the panel was charging the EB, which was now at 13.5v and therefore triggering the isolator.
So the question is - do I rip out the intelligent isolator and replace it with the normal changeover relay, or just leave it connecting the two LBs to the EB, until their volts drop to 12.8v?
I think I know the answer. Another waste of £20, just like the other assorted glitzy things that look good on ebay / temu /amazon and so on. I've got plenty of 20A relays in the man shed. More wiring . . . .harrumph. I'll be soldering several of their pins in parallel. I don't trust these little plastic relays, having been brought up with GPO 2000 type relays with Platinum contacts. I'll need several relays - if the alternator can chuck out 95A then I don't want some poxy 10A relay contacts getting in between the alternator and two 100AH Lifpo batteries, not to mention that something in the hab area might be turned on . . .

It's just a quirk of using a VSR, because it closes at 13.3 volts it's bound to close whenever you charge the starter battery be that by alternator, maintenance mains charger or in your case solar. I don't think it's particularly bad BUT because the VSR is always monitoring the input voltage it will always be consuming a certain amount of standing current from the starter battery. Whether or not this will be detrimental will depend on the amount of solar you have and the standby current drain, if there's a large deficit it could cause a problem in the winter if the van's layed up.
A conventional SCR would remove the risk and if you use one with a high current rating would probably be better suited to directly charging your lifepo4. In case you're not aware, charge current will depend on :
Alternator voltage.
Battery voltage (this will depend on SOC)
Wiring/contact/component resistance in the circuit.
The battery voltage in particular is very different between lifepo4 and lead acid, component resistance to a lesser extent.

 

[gasgas]

I've ordered a couple of these.

Pardon our interruption...

Mainly because although there are what look like identical listings, this is the only listing that shows the insides, that look as if they might actually take the charging current. It's not going to be 100A of course but these look as if they have actual copper wiring inside and decent looking contacts, and I like the nuts and bolts wire terminations rather than push-on spades. I'll only use one for the battery charging and keep the other one in a drawer which my children will inherit and wonder what to do with. Unless I think of another use for one.
Until it arrives I'll look again at the installed VSR and see what current it draws when it is not turned on, but connected to the EB. It did get a bit warm when it was operational.

 

[mistericeman]

I've ordered a couple of these.

Pardon our interruption...

Mainly because although there are what look like identical listings, this is the only listing that shows the insides, that look as if they might actually take the charging current. It's not going to be 100A of course but these look as if they have actual copper wiring inside and decent looking contacts, and I like the nuts and bolts wire terminations rather than push-on spades. I'll only use one for the battery charging and keep the other one in a drawer which my children will inherit and wonder what to do with. Unless I think of another use for one.
Until it arrives I'll look again at the installed VSR and see what current it draws when it is not turned on, but connected to the EB. It did get a bit warm when it was operational.

I can't see it drawing anything significant ...
I never noticed anything measurable on the durite version we had on the transit .

 

[Pudsey Bear]

Not my best subject and I undestand a very small %age of these threads but I used the Smartcom VSR in the self build, a great bit of kit at the time.

Could you not use it the other way round as it is adjustable, to sense the solar energy input and the LB to send some charge to the VB?

Asking for a friend

Curtesy of Wissel

 

[mistericeman]

Not my best subject and I undestand a very small %age of these threads but I used the Smartcom VSR in the self build, a great bit of kit at the time.

Could you not use it the other way round as it is adjustable, to sense the solar energy input and the LB to send some charge to the VB?

Asking for a friend

Curtesy of Wissel
View attachment 140749

Those smartcom relays were frankly junk ...
I remember folks raving about them when they came out on the market ...
I fitted several and never had one work reliably for long ...
Then started using Durite VSR s
And had great success with them .