Fitting Solar Panels

[sixbytwelve]

School boy question. I want to fit some solar panels to my boat but want to check that I'm going about it correctly as I'm pretty new to working with 12V electrics. Do I or can I connect the cables from the Solar Charge controller directly to the + and - terminals on my battery bank or to the isolator terminals? I know that the best way should be to have the batteries connected to bus bars but my system doesn't have these at present, the batteries are connected to the isolator with an Adverc battery management system and a constant feed to the fridge. See photos. Also is it ok to run the 12V cables from the panels across (at 90degrees to) other electric cables (12v and 240V) in my switch cupboard? Any pointers and advice gratefully recieved.

 

[Boater Sam]

Tidying some of that wiring whilst you are at it would be a sound idea.

That positive battery link with 3 thin cables is particularly nasty.

12V and mains cables can cross but there must be an insulating barrier, better to use conduit or trunking for one or the other. Same with gas pipes and any cables.

[Alan de Enfield]

Connect your solar DIRECTLY to the battery BUT ensure you have a suitably sized fuse as close as possible to the battery end.

 

The solar must not be disconnected from the batteries or it will 'blow up' your controller - the solar panels MUST be disconnected from the controller 1st, then at the batteries

[Tony Brooks]

I disagree with Alan but not by much. Connect your solar to the BATTERY side of the isolator. The more comparatively thin cables you have close to or on a battery terminal the greater the chance of failure cause by acid corrosion AND thaat corrosion is likely to have wicked down the cable requiring a lot of cable to be renewed when it does fail.

 

Fit a suitable fuse close to thee battery end of your solar wiring to protect the cable in case it shorts out between the battery and controller.

 

Personally I would move all those small cables unless one is for a Smartguage or some other item that specifies direct to the battery from the battery terminal to the battery side of the master switch. You also need to ensure all those cables are allowed to be direct to battery by the BSS. Any circuit that is wired like that needs a fuse close to the battery end.

[Nightwatch]

This thread is a fine example of a thread I don't get involved in. The majority of the content is gobble-de-gook. 

 

I had my controller installed by a proffessional, I fitted the panels. Eventually.

[rusty69]

Do you have a shunt based battery monitor? 

[sixbytwelve]

4 hours ago, rusty69 said:

Do you have a shunt based battery monitor? 

I don’t believe I do, just a volt meter

[Detling]

5 hours ago, Tony Brooks said:

 Connect your solar to the BATTERY side of the isolator.

That defeats one of the best aspects of solar. Connect via a fuse direct to the batteries and you can then turn off the boat with the isolator leaving the solar to maintain the batteries whilst you are at home. This avoids having to plug in to shore power for battery maintenance with the associated galvanic issues. Wiring the solar via the isolator will lead inevitably to someone disconnecting the battery from the controller, with the solar panels in full sun, what happens next depends on the controlle,r most will just reset to 24 volt charging when reconnected trying to cook the batteries, but some will emit the white smoke of death.

[Robbo]

2 minutes ago, Detling said:

That defeats one of the best aspects of solar. Connect via a fuse direct to the batteries and you can then turn off the boat with the isolator leaving the solar to maintain the batteries whilst you are at home. This avoids having to plug in to shore power for battery maintenance with the associated galvanic issues. Wiring the solar via the isolator will lead inevitably to someone disconnecting the battery from the controller, with the solar panels in full sun, what happens next depends on the controlle,r most will just reset to 24 volt charging when reconnected trying to cook the batteries, but some will emit the white smoke of death.

Re-read what Tb said!   I would prefer a bus bar if using multiple connections to the batteries.

Edited June 25, 2018 by Robbo

[Tony Brooks]

2 minutes ago, Detling said:

That defeats one of the best aspects of solar. Connect via a fuse direct to the batteries and you can then turn off the boat with the isolator leaving the solar to maintain the batteries whilst you are at home. This avoids having to plug in to shore power for battery maintenance with the associated galvanic issues. Wiring the solar via the isolator will lead inevitably to someone disconnecting the battery from the controller, with the solar panels in full sun, what happens next depends on the controlle,r most will just reset to 24 volt charging when reconnected trying to cook the batteries, but some will emit the white smoke of death.

 

Please read my answer. The BATTERY SIDE OF THE MASTER SWITCH - note BATTERY SIDE - is live all the time it is connected to the batteries so connection the solar there still allows it to charge with the isolator turned off and avoids thinner connections on battery connectors.

 

I did NOT say "LOAD SIDE OF THE ISOLATOR" because that would do as you describe.

 

 

1 minute ago, Robbo said:

Re-read what Tb said!   I would prefer a bus bar if using multiple connections to the batteries.

I agree with that as well as long as it is a bit away from the batteries.

[Detling]

Sorry bit dyslexic here must read wrong words rite or else.

[Tony Brooks]

2 hours ago, Detling said:

Sorry bit dyslexic here must read wrong words rite or else.

Tis easy to do, I do it all the time but luckily someone often notices.

[Richard10002]

6 hours ago, Tony Brooks said:

 

I agree with that as well as long as it is a bit away from the batteries.

Why a busbar a bit away from the batteries? How far is a bit?

[Tony Brooks]

Far enough away to be well clear of any acid mist - even sealed batteries have a vent. So if your batteries are in a case with a lid screwed onto the outside of the case would be OK, if the batteries were semi-open the a bit further away.

[Richard10002]

3 hours ago, Tony Brooks said:

Far enough away to be well clear of any acid mist - even sealed batteries have a vent. So if your batteries are in a case with a lid screwed onto the outside of the case would be OK, if the batteries were semi-open the a bit further away.

The reason I ask is that I gave just fitted an enclosed busbar about 8-12 inches away from, and above, the batteries which are on the swim and not enclosed. The +ve terminal was getting overcrowded, so a busbar nearby seemed to be the answer.

 

All the cables that are attached to the busbar were previously attached directly to the battery, so much closer to the mist that you talk about. Presumably the mist causes the corrosion and powdery growth that I see on my starter battery but never on my domestic batteries?

[MtB]

30 minutes ago, Richard10002 said:

The reason I ask is that I gave just fitted an enclosed busbar

 

Ah now which busbar did you select?

 

They seem to cost nosebleed money for such simple items. Did you find a sensibly-priced one or did you take out a marine mortgage?

[Richard10002]

12 minutes ago, Mike the Boilerman said:

 

Ah now which busbar did you select?

 

They seem to cost nosebleed money for such simple items. Did you find a sensibly-priced one or did you take out a marine mortgage?

This one was £36 with 4 terminals capable of a total of 300A as the inverter current passes through it.

 

I've recently bought a couple of 200A busbars for about £17 each from 12 Bolt Planet, which are in the charging source part of the system.

[Chewbacka]

1 hour ago, Richard10002 said:

This one was £36 with 4 terminals capable of a total of 300A as the inverter current passes through it.

 

I've recently bought a couple of 200A busbars for about £17 each from 12 Bolt Planet, which are in the charging source part of the system.

I bought some heavy brass strip and brass m8 bolts on eBay.  Made my own

[WotEver]

On 25/06/2018 at 09:09, Alan de Enfield said:

The solar must not be disconnected from the batteries or it will 'blow up' your controller - the solar panels MUST be disconnected from the controller 1st, then at the batteries

The other way round. 

 

The charge controller MUST be connected to the batteries BEFORE the solar panels are connected. 

[Alan de Enfield]

37 minutes ago, WotEver said:

The other way round. 

 

The charge controller MUST be connected to the batteries BEFORE the solar panels are connected. 

 

BUT - I was talking DISCONNECT

On ‎25‎/‎06‎/‎2018 at 09:09, Alan de Enfield said:

 

The solar must not be disconnected from the batteries or it will 'blow up' your controller - the solar panels MUST be disconnected from the controller 1st, then at the batteries

And Connection (as you correctly state) is the reverse of that, ie, batteries to controller 1st, then controller to Panels.

[WotEver]

1 hour ago, Alan de Enfield said:

 

BUT - I was talking DISCONNECT

And Connection (as you correctly state) is the reverse of that, ie, batteries to controller 1st, then controller to Panels.

Oh yeah.  

 

I must just learn to read properly. 

I must just learn to read properly. 

I must just learn to read properly. 

I must just learn to read properly...

[Richard10002]

10 hours ago, Chewbacka said:

I bought some heavy brass strip and brass m8 bolts on eBay.  Made my own

Yep! No,problem making the metal bits, but I wanted them with nice backing and covers.

[MtB]

11 hours ago, Richard10002 said:

Yep! No,problem making the metal bits, but I wanted them with nice backing and covers.

 

Quite. Devising properly insulated mountings and secure covers is more time and effort than the making (simple) brass bits. 

[sixbytwelve]

Thanks for all the advice, now to get the job done ?

[LadyG]

On 26/06/2018 at 11:29, Richard10002 said:

This one was £36 with 4 terminals capable of a total of 300A as the inverter current passes through it.

 

I've recently bought a couple of 200A busbars for about £17 each from 12 Bolt Planet, which are in the charging source part of the system.

https://www.12voltplanet.co.uk/

how to select cable 

 

Edited September 15, 2018 by LadyG