Solar panels

You're fortunate to have (I assume) the Sargent EC155 power supply/controller, which is a simpler design than the current generation such as the EC500 and 700. So it's likely to be similar in standby power efficiency to the EC328.

Provided you can find a location on the roof where it's not shaded by something else, a 100W panel should easily be adequate for winter battery maintenance, and you should be able to use a 2-channel controller such as the one that Greyhound describes in one of his other threads.  

The Votronic MPPT 2-channel controllers would be an alternative, but they are quite a lot more expensive, and don't allow you to set the proportions of solar panel output.

There are simpler alternatives, such as a single-channel controller, but if you're going to the trouble of having an install done, you may as well get both batteries covered, as it will not cost a huge amount more.

Sally wrote:This is the panel I have.

Yes, the EC50 and EC51 are both, as I understand it, designed to work with the EC155 power supply/controller. The EC155 is the larger box with fuses on the front, and that is where most of the functional circuitry is. Presumably you have an EC155 unit hidden away somewhere?

Peter's reference to negative first is simply the safest way to disconnect a battery - it means that you are much less likely to short the battery out. You disconnect the negative first and the positive second. You could if you wanted leave the positive connected and the battery would not be able to drain - but IMO it is better to completely disconnect it.

I respect Roopert's opinion greatly but personally I just disconnect the negative as there is then no electrical need to disconnect the positive and I firmly believe that if you don't really need to disturb something, it is better not too.

I can't help with fitters in your area but SMC at Newark are not a million miles away and will do a good job.

Roopert wrote:You could if you wanted leave the positive connected and the battery would not be able to drain - but IMO it is better to completely disconnect it.

Apologies - I lost track of the context of this thread. Contrary to what I said above, there is absolutely no reason not to disconnect just the negative if you are just wanting to disconnect the battery temporarily.

Greyhound wrote:

Roopert wrote:

Greyhound wrote:The new controller has an optional display unit (which I got) which I fitted under the bench seat where I can change the percentage charge to each battery and check on the voltages/amps being sent.

Apologies if this has already been stated elsewhere, but what controller did you get, Greyhound?

I bought the photonic universe 2 battery PWN controller with additional control display:
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I know MPPT is technically more efficient but this is the 4th time I've done a solar install using these controllers and they have worked faultlessly for me and are a very good affordable controller, especially with the useful display so you can change the ratio's etc.  For small setups like this I feel PWM is perfectly fine, but that's just my opinion and have no issues either way.  If I was fitting a lot of high power panels to really go for it, I'd definitely choose MPPT.

As mentioned, the wiring is already all in place, and it's a simple task to tap into the existing battery connections and move the solar wires from the Sargent board to the new controller.  Definitely pleased with the result.

So just to get my head around your installation, I take it the Sargent still charges via EHU and solar via new controller.

Sorry for such a dim question, but so many threads about this subject and my old brain is confused.

I seems this is the main subject with modern AS vans, my friend round the corner has a 2018 Hymer  Homecar, no solar, very seldom EHU and never has had a battery problem.
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Richard

Greyhound wrote:Yes you've got it :)

Sargent still controls the EHU charge and it's it the solar that is now isolated.

So even with the system completely shut down I'm getting full solar to both batteries with no unnecessary current draw.

On EHU there's obviously no problem with that so the Sargent is free to manage that as before.

Thank you for your reply. I was hoping that was the case, I have an electrical back ground, although mainly at 50v and have seen some flashes and bangs in my time and didn't want to blow up the van .

Looks like the way to go forward.

Thanks
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Richard

Slow-Lane wrote:Does anyone know of anything specific I need to bear in mind when planning this work?

On the older vans, there's really not much to worry about. I've done a 150W installation on a 2005 Trooper (which has one of the early Sargent PSU2005 power controllers) without any trouble at all. In that case I used a single-channel solar controller connected directly to the leisure battery, and changed the Split Charge Relay - which in those days was separate from the Sargent unit - for a Voltage Sensing Relay.

I did the latter because it was easier than using a dual channel controller and having to run another wire into the engine compartment. The VSR allows the solar panel to charge the vehicle battery through the same wire as is used to charge the leisure battery from the alternator when the engine is running.

Generally on the older vans, the most difficult thing is planning how to run the wiring without it showing too visibly. The electrical side is not complex at all, really.

If you're a complete novice at electrics then it probably would be a good idea to go to one of the firms that specialises in solar installs. It's not a complex thing to DIY if you've done a bit before, but it's not one that I would recommend as your first ever!

A split charge relay is nothing more than a relay that connects the engine battery to the leisure battery when the alternator produces output - so it can charge both batteries together. It is one-directional only, so will only operate when the engine is running.

A VSR includes more circuitry internally, so again it sits between the two batteries, but is able to detect voltage increases on either side, so it can detect when 1. the vehicle battery is being charged by the alternator, 2. the leisure battery is being charged via EHU or 3. the leisure battery is being charged by a solar panel.

In each case, it has a threshold voltage above which it will connect the two batteries together, so any of those events can allow both batteries to charge (provided the VSR's threshold voltage is exceeded). The threshold is there mainly so that if one of the batteries is very heavily discharged, it will be charged on its own for a while without having the other battery's load added on as well.

In your situation, with both batteries side by side, it would probably make sense to go with a dual channel controller. I would go with something like the one that Greyhound used, with the controller down by the batteries and a remote display. I didn't install a remote display on the Trooper because there wasn't anywhere easy to install it. I did on the other installation which used the Votronic dual-channel controller - though in truth that was a bit of a waste of money, because once I get over the novelty, it's something I hardly ever look at (and IMO that's how it should be - fit and forget).

Peter Brown wrote:

Caraman wrote:He may only have been referring to the EC700 when it is shutdown.  The attached file was the EC400/EC450 System Charging Guide which includes the EC500 but doesn't say where the solar charge goes when the PSU is shutdown.  I am waiting for another response from Sargent which might give greater clarity.

In section 3.6 'Solar Charge Management' of the Sargent user instructions for the EC500, the last sentence specifically states that if the system shutdown button is operated all solar charge goes to the leisure battery.  In the same paragraph for the EC600, 700 and 800 that last sentence is omitted and there is no mention anywhere of where the solar charge goes when the system shutdown is operated.

I have just heard from Sargent who confirm that when the system shutdown button is pressed, for the EC400/450/500 all the solar charge goes to the leisure battery but on subsequent systems EC600/700/800 it all goes to the vehicle battery.  They also acknowledge that over the winter period the solar charge on its own may not be enough to keep both batteries charged.  IMO this is more likely in the North than the South and if the solar panel is soiled, shaded or facing away from the sun which it might be if levelling wedges are used to stop rain water pooling on the roof.  I think it is best to try and use the motorhome at least once a month if only for a day.  This will ensure the batteries are charged, allow fresh water to be pumped through the system and relieve the tyres.  If the motorhome is going to be out of use for much longer than this, the leisure battery should be removed, the water system should be sterilised and the motorhome placed on axle stands.

Thanks for that Caraman. So as long as tracker etc is powered from vehicle battery AND owner remembers to shutdown EC700 then outside storage should be ok all year from a solar charge point of view and no need for battery master or the like.

Peter Brown wrote:Thanks for that Caraman.  So as long as tracker etc is powered from vehicle battery AND owner remembers to shutdown EC700 then outside storage should be ok all year from a solar charge point of view and no need for battery master or the like.

I think so.  If the EC700 is shutdown some charge, even though it may not be much in the Winter, will go to the vehicle battery.  If the ignition red button is pressed, no charge will go to the vehicle battery.   If the vehicle is being stored under cover or if the solar panel isn't working, it would be better to press ignition red button as per the Boxer on-line manual.  This is only my opinion - I am no expert.