MPPT survey (EC700 smart bypass surgery!)

Dbvwt wrote:I never thought the day would come but I’ve finally had enough of Solar threads 

To keep in the spirit of this one..

2018 Symbol with EC500
Votronic MPPT 250 dual
Self install (total cost £121 and two and a half hours)

In the more general picture, I really don’t understand why there are still so many threads that question the solution that has worked pretty much 100% for everyone with an EC500/700 that has done the mod due to issues with the Sargent and Solar.

It is so straightforward. Fit a dual MPPT controller (the popular Votronic or Epever) wired direct to both batteries. Wire the solar panel to the new controller bypassing the Sargent completely.
It just works.

  From a newbie perspective - I think an issue is that if you have no understanding of this - you wade through it all and then lose the will to live - I am still trying to find a simple step by step guide to how to do it.  

It isn't in doubt that it works - how to do it however is an issue - I'm a retired teacher and this is an issue of simplicity and clarity. So many have done it but because of the sheer volume of material now on it - newcomers, particularly those with no electronics know how or who have never done anything like this before, or who are just plain idiots like me (  ),  are just overwhelmed by all the pages. A really simple step by step guide for idiots like me would be deeply appreciated but I know it takes time and dedication to do and actually people in the past have worked it out for themselves so why cant we. I am slowly getting my head around it but its like wading through treacle at times. Even simple statements like 'wire to batteries directly' - needs unpicking for those who have never done something like this before. The wisdom on this forum and the great lengths people go to help newcomers is truly extraordinary, astonishing and humbling. But on the solar issue - if people are still asking basic questions - then I suspect that it is partially because it has become difficult to grasp the big picture due to all the pages of excellent advice. I am reluctant to go to Youtube videos by people I dont know - on this forum - I dont know anyone but I do recognise expertise, kindness and good will inherent across this forum and therefore I am more trusting of people here.

 Its a sort of self fulfilling catch 22 problem - kind people answer the questions at length - generating even more pages  which newcomers then struggle to get through - its kinda funny in a really nice way. On the other hand going through the pages is worth the effort in terms of the vast amount of learning available in there - but you end up going off at tangents because of slight digressions in threads or because interesting other options are given - and so you lose what it was you were trying to get to grips with. Of course - this is probably just me - lets face it - those who have helped me so far have already worked out I'm not the sharpest of people am I?    

Above is the first really simple summary I have seen (thank you). 
Now - how do you fit the controller, how do you wire it to the batteries directly, how do you wire the solar panel to the new controller whilst bypassing the EC700 (GOD how I hate that thing); how easy is it for a complete newbie novice and then if i want to add an additional solar panel - how do I do that into this new system? And, most importantly for newcomers and newbies - if you bypass the system - are you invalidating your warranties on your new pride and joy? 
I really am quite dim aren't I - and if I have missed the step by step idiot guide - I am sooooo sorry ! 

No. you are not dim.

If its not your subject get someone else to do it. There are safety concerns, people do get the wrong end of the stick and do things wrong.

Personally I think only an idiot would attempt to write an idiots guide.

Idiots guide was wrong words to use.....step by step guide would have been better

Plymouthwelshboy wrote:Idiots guide was wrong words to use.....step by step guide would have been better

Such as the excellent guide given on this Forum on how to replace the Whale water system with a Shurflo pump which requires both electrical and plumbing work.

way back in 2009, i had a 2007 Swift Bolero with a Sargent system and I had a solar system installed and i knew then which plug was the solar one in what ever EC unit i had then...P14 from memory...
i started to sketch out the steps for PWB but soon realised that the more modern EC units would be different and i had no specific knowledge of the way the cabling is routed/connected into/out of them.
a description of what is being tried to acheive isnt difficult, (ive written many an IT manual in the past) its how the existing system needs to be 'changed' which i cant comment on.
so, obviously, this needs to come from an AS owner who has done it.
however, i agree with Marconi that working with 12v batteries requires care and, although the 'instructions' may seem straighforward to some (author) it can still be confusing to the new user...
its normal for technical documents to reviewed (often more than once) before being released to the folk who will make use of them...this wouldnt happen on here unless a peer group was formed...

On request of a Forum member I started to write a guide, it got to two pages of A4 and was nowhere near enough, every step brought forth more questions and misunderstandings from the requester.

It's impossible to cover all the differences, even within models and all the materials, tools, procedures and safety aspects. If you are someone capable of safely doing the work you will know and a lot of the things that would need explaining will not be needed.

The information published by Votronc is ample, plus unplug the existing Solar controller from the EC700.

People complain about the threads being too long, this guide would need to be far longer. Even with a peer group who is going to take ultimate responsibility.

I remember a safety issue in a another request on here the OP took no notice of several posters telling him of the risks, his final comment was that he was going to do it his way. 

With apologies to LPDP who wanted this thread to remain uncomplicated.

marconi wrote:On request of a Forum member I started to write a guide, it got to two pages of A4 and was nowhere near enough, every step brought forth more questions and misunderstandings from the requester.

It's impossible to cover all the differences, even within models and all the materials, tools, procedures and safety aspects. If you are someone capable of safely doing the work you will know and a lot of the things that would need explaining will not be needed.

The information published by Votronc is ample, plus unplug the existing Solar controller from the EC700.

People complain about the threads being too long, this guide would need to be far longer. Even with a peer group who is going to take ultimate responsibility.

I remember a safety issue in a another request on here the OP took no notice of several posters telling him of the risks, his final comment was that he was going to do it his way. 

With apologies to LPDP who wanted this thread to remain uncomplicated.

Well said Marconi, particularly paragraph 2 which sums up the situation well.

Dare I say it, it's important to be honest with recognising your own skills and limitations before  considering any work.

Whilst doing it yourself seems attractive and may save some money, if things go wrong it could end up costing you more.

If you've had a look around and don't feel comfortable or know where to start, I would suggest seeking professional help.


Can we now return to the original intention of this thread of being just a simple survey?

2019 Kemerton XL with EC700
Votronic MTT 250 Duo Dig solar controller
self install
Both battery voltages were maintained (ie full) over this winter months, no EHU, EC700 off by the black isolation button. Actually I did have EHU but only on for a Dimplex Chico heater to reduce damp, the thermostat set for about 5 degrees.

Despite the standard A-S fit of an 80W solar panel, the EC700 PSU if on can consume about 6+ amps in 24 hours. On our previous A-S Duetto there was no such constant current drain, all the power generated from the solar panel that I retro-fitted was available for us, to be used when off-grid powering the Duetto's power hungry diesel heater and modest TV, not consumed by some fancy microprocessor based PSU.

Perhaps I should stop there and ask how good are your DIY skills, you OK using a soldering iron?

Here I unplugged the Kemerton XL roof's A-S solar feed to our Sargent solar controller that connected to our EC700, having already sourced twin cable from eBay. A-S have used Mate-N-Lok plug and sockets to join the cable feed from the 80W roof solar panel to Sargent's basic solar controller. The Sargent solar controller is probably a rebranded cheap Chinese made unit. They mean you, A-S mean you to generatly have you camping on campsites where you are connected to EHU, not off-grid.. Consider your 80W solar panel is there to support the Sargent PSU system, it's not generating power for you to use, it's there to feed Sargent's beast.

I made up a cable with one end of a Mate-N-Lock connection so it mated with the feed from the solar panel and ran the cable to my Victronic solar controller. If I need to I can revert in about 2 minutes to going back to the crap crap solar system that A-S have allowed Sargent to dictate to them.

https://www.autoelectricsupplies.co.uk/product/683/category/7

I assume the cheap rebranded Chinese controller used by Sergent is buried in the rats nest of wires that make up the EC700.  What has to be removed to get to it?  Having found it, is it really as simple as disconnecting the 2 wire solar panel feed from the existing controller and connecting it with an extension to the Votronic which presumably comes with its own installation/user manual?  Do the outputs from the existing controller remain connected to the EC700 or are they disconnected as well?  For safety it must be best to disconnect the motorhome from the EHU and cover the solar panel whilst the work is being done.  It is best to fit in-line fuses close to where the Votronic connects to each battery?

On our 2019 Kemerton XL the Sargent solar controller was mounted on a side wall, behind our EC700. On some earlier A-S vans the PWM solar controller was more closely associated with the Sargent PSU, not a bad arrangement for its time.
I'm not sure what I did with our van, with no solar power going to the disconnected stock Sargent solar controller it's just passive. I think I will have disconnected it's onward connection to the EC700. It's all Mate-N-Lock plug and socket after all.

Certainly cover the solar panel when working on the electrics so the solar feed cable has no power. I did have a problem with our Duetto's radio. I had to do a reset when the power was off and it was necessary to cover up the solar panel with some carpet tiles to completely de-power the radio.

With Our Kemerton XL I fitted fuses in the feeds from the solar panels to the Votronic 250 Duo Dig (I ended up with 2 x 80W A-S solar panels). What I haven't yet fitted is a fuse in the feed from the Duo Dig direct to the leisure battery, though the Duo Dig itself does have a 20amp fuse built in. I did fit a fuse in the Votronic's 1 amp feed to the vehicle battery.