Autosparks and solar gurus please..... (1 Viewer)

[Trikeman]

Gents,,,,,,,,
This is the leisure battery wiring on my Autotrail Apache 700SE Motorhome I just drew up (Below). Originally it had 1 leisure battery, however a second was fitted later.
When standard, the van came with one leisure battery however the van is fitted with two connection blocks - to enable second battery fitment. With one battery only one connection is used (a). When a second battery is fitted, an additional harness can be purchased/fitted into connection (b) to enable second battery connection. When two batteries have been fitted, charge from the PSU2005 leisure battery charger is to both connections (a) and (b). My van has two batteries and wired as in the diagram below.

My question is - I am fitting my van with a solar leisure battery charging system - to provide the best charging scenario both batteries require connection in parallel. As both batteries are being charged from one source my assumption is that the positives feeding both connections (a) and (b) are the same - but for ease of additional battery fitment are by separate connections (as above). The assumption is also the same for the negative. If this is indeed the case, would the solar wiring positive (c )(yellow dashed line) and negative (d)(purple dashed line) be suitable and safe as it still remains ‘in parallel’.
I really don’t want to go down the route of wiring to one battery then the charge having to go around the van to eventually come back down the other cable to charge the other battery – the first battery would get the lions share of the charge always. – Does this make sense?
Please excuse the photo - I took it off my screen
Trikeman.

.

 

[Techno]

It is what I would do myself but I'd like to hear any arguments against.
Keep up the blog :thumb:

 

[Reallyretired]

Looks OK.

The two connection blocks will be paralleled somewhere in the system anyway so both should still charge even if you only connect to one battery, however there may be extra resistance in the circuit so it would probably be more efficient to wire as you have indicated.
If your control panel displays separate voltage measurements for each battery separately then, as you have effectively just got one big battery, they will read the same.

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[dave newell]

What year is your motorhome and what Sargent PSU unit is fitted? If its a late-ish van and has the EC325 fitted then this has a built in two channel 100 watt solar reg and it will automatically split the chargew between leisure and engine batteries as required. If its a different EC/PSU unit then what you have drawn is fine but not really necessary as both leisures are connected in parallel and the coupling point is close to the batteries. You could connect pos to one of the lesiures and neg to the other as a half way house between what you have drawn and simply connecting solar charger to one battery and letting the wiring do its work but in all honesty I really doubt you would find any measurable difference in charging whichever of the 3 options you use.


D.

 

[Ber090]

Trikeman and Dave , It is worth remembering that the recent Sargent psu's are for MAXIMUM 100w panels. I had a warranty claim when my Dealer fitted 150w panel through the psu and fried it!
Cheers
Bernie

 

[hilldweller]

Trikeman and Dave , It is worth remembering that the recent Sargent psu's are for MAXIMUM 100w panels. I had a warranty claim when my Dealer fitted 150w panel through the psu and fried it!
Cheers
Bernie

That sounds pretty disgraceful. Only 50% overload and it dies. 8A or 12A when a transistor the size of your little finger nail and costing nothing will pass 400A. Poor design.

On top of that did you ever get enough sun for 150W, if it's not tilted you did not.

I think you may have paid for the dealer's cock up.

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[Trikeman]

What year is your motorhome and what Sargent PSU unit is fitted? If its a late-ish van and has the EC325 fitted then this has a built in two channel 100 watt solar reg and it will automatically split the chargew between leisure and engine batteries as required. If its a different EC/PSU unit then what you have drawn is fine but not really necessary as both leisures are connected in parallel and the coupling point is close to the batteries. You could connect pos to one of the lesiures and neg to the other as a half way house between what you have drawn and simply connecting solar charger to one battery and letting the wiring do its work but in all honesty I really doubt you would find any measurable difference in charging whichever of the 3 options you use.


D.

Hi Dave (and all) Thanks for getting back.
The Sargent system is a PSU2005 and has no solar controller (I've been assured). On this set up I'm fitting I have a 20a MPPT controller fitted to take care of the panels (2x100w).
I did speak to Sargent a while ago about the leisure battery wiring and they said the positives join 'somewhere' in the loom. I couldn't see anything wrong with putting the two positives together (battery end) and feeding the one battery positive, and then the two negatives together feeding the negative on the same battery. Then connect positives of each battery with a mahula of a cable, and the same to the negatives (traditional in parallel). My old MoHo was wired like this.
I think the only reason for Autotrail to make two individual supplies is to enable 'easier' fitment of another battery over the single.

I just really wanted to know, as if this is the only reason then I understand, just wanted to know if indeed the two positive supplies come from/to the same bit,,,,,,,, and not something totally different - if that makes sense.
:Blush:
Cheers all,

Trikeman.

 

[Ber090]

Hilldweller, Steady on! Has someone upset you?
I am very happy with the performance of 150w panel into 2x 110 batteries.
My dealer was great and held his hands up the minute he discovered the problem and paid for everything. I would fit the same again as it works perfectly for us. I cannot and would not dream of suggesting how others would find it!
Cheers
Bernie

 

[dave newell]

Trikeman and Dave , It is worth remembering that the recent Sargent psu's are for MAXIMUM 100w panels. I had a warranty claim when my Dealer fitted 150w panel through the psu and fried it!
Cheers
Bernie

Bernie, if you read my post fully and closely you will see that I did say the EC325 as a 100Watt solar reg built in. I have no problem with this, we often work with Sargent kit and find the company are always helpful. Perhaps if your dealer had done similar he would have known better than to put a potential (pun intended) overload of +50% into the system and then not done it that way.

D.

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[Ber090]

:thumbave, I did read your post closely and fully agree with you. All I was doing was reminding the original enquirer about the possibility of overload. I must also add that Sargents were more than helpful with my problem.
Cheers
Bernie

 

[Peter_n_Margaret]

I think the 2 batteries need to be paralleled at the terminal blocks and with BIG cable.
The controller could be connected to the same terminal blocks.
It is important to both load and charge them evenly at all times.

There should also be fuses on the +Ves as close to the batteries as possible.

Cheers,
Peter