Not a Self-build, but a Tweaker

wildebus

Forum Member
With all the little extra controls I add to my Motorhome, easy to forget what does what.

So finally got round to making up a label for the first pair of switches ...
The AMT Starter Battery Maintainer works automatically based on voltage levels of Starter and Leisure Batteries. However it is possible by connecting +12V to a specific connector to override the program and force it to be on 90% of the time (9 seconds on, 1 second off and repeat). Also if you remove the ground connection, that disables the AMT entirely.
This pair of switches will allow you to either override, disable, or leave to run automatically just by setting the switches rather than having to make and break connections manually, but remembering how to set them is key - and a nice neat label will help :)

Switches are inset into a custom made CBE mount, so measured up the hole position and mount size, creating a templace for printing and cutting on the Cricut 2D plotter/cutter, and then applied to the mount which is then inset into the CBE Frame.
IMG_20220608_223140_8.jpg


Switches then fitted into the mount
IMG_20220608_223232_0.jpg

Switches and Positions colour-coded ... Red set to 1 (to Red writing) = Override; Black set to 0 (to Black writing) = Off; Switches to Green Writing (Red to 0, Black to 1) = Auto mode - so as programmed (which is the default mode).

This is the switch mounted back in place next to another pair that is labelled up with a simple label printer strip.
IMG_20220608_225856_7.jpg

I'll do a similar white cover for this other pair (This left-hand pair can be used to quickly override the programmed behaviour of the Multiplus Inverter in specific ways, and having a more informational label with these two 3-way switches will be handy compared to just "AES" & "SOC")
 

wildebus

Forum Member
It might be best to start writing the operators manual now for the new owner, ready for when you sell it. ;)
Actually ... this is something that is missing from just about every motorhome on the market. How often do you see a question on a forum or facebook group asking "what is this switch for?" (on commercially built MHs, not self-builds)? It is hard to resist replying "how the hell do I know?", especially when the photo is so zoomed in you don't even know where it is.
It took me months to work out how the original reversing camera worked in conjunction with the drop-down Cab TV :(

I do have full wiring diagrams in a folder for both the original Autotrail wiring and how it relates to this specific Motohome (rather than just a generic Sargent download) as well as the additions and enhancements. These labels will have a related reference page :)

And talking labels ... just made the label for the 2nd pair of switches. Bit trickier trying to fit in a description, but at least it is an improvment on "AES" and "SOC" :rolleyes:

IMG_20220609_110255_4.jpg

For anyone interested ....

AES switch on the left deals with the Multiplus Inverters Standby mode. It is programmed so it doesn't wake up unless there is a load over 54W so I have some AC powered kit that won't kick off the Inverter - laptop charger is one example, and the Microwave is an 'eco' model so needs a small power level to wake itself up to then be started.
So if I set the AES Switch to 2, it disables AES and the inverter is just ON, and these low power items will work;
Set to 1, the Inverter is ON as long as the battery SOC is not below a minimum level (60% I think?) and if it is, reverts back to AES mode. Having an AES override linked to an Battery State of Charge can help prevent a standby powerdrain over an extended period;
And set at 0 (the default) means run as programmed.

the SOC-SSR Switch is essentially a Water Boiler/Heater Controller.
On 0 (Auto and the default), the Heater only has power when the SOC is above the start level (around 95%) and then stays on until it drops below a minimum level (the 60% mentioned above);
However, if I put the switch into position 2 (SOC O/R = Override) then the Heater has power regardless of the battery level;
And at position 1 (60m O/R), the SOC level is ignored for 60 minutes and then re-enabled. The idea of this option is that you can put it on the 60 minute override to give the water an initial heating session (the 850W will heat up the 10L of water to temp in just around 1 hour) and then don't have to remember to switch it off in order to save the battery power further, it is done for you.
(PS. I do have a separate switch to turn the heater on and off - the switch above just determine if the circuit itself has power by enabling an SSR - Solid State Relay. And if there is EHU present, the battery SOC is ignored automatically as power is provided by mains passthrough)

It may seem complicated, but it isn't really and combines programmed settings to maximize energy efficiency with manual overrides to maximize usability without having to start reprogramming anything :)
 
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SquirrellCook

Forum Member
AES switch on the left deals with the Multiplus Inverters Standby mode. It is programmed so it doesn't wake up unless there is a load over 54W so I have some AC powered kit that won't kick off the Inverter - laptop charger is one example, and the Microwave is an 'eco' model so needs a small power level to wake itself up to then be started.
So if I set the AES Switch to 2, it disables AES and the inverter is just ON, and these low power items will work;
Set to 1, the Inverter is ON as long as the battery SOC is not below a minimum level (60% I think?) and if it is, reverts back to AES mode. Having an AES override linked to an Battery State of Charge can help prevent a standby powerdrain over an extended period;
And set at 0 (the default) means run as programmed.

the SOC-SSR Switch is essentially a Water Boiler/Heater Controller.
On 0 (Auto and the default), the Heater only has power when the SOC is above the start level (around 95%) and then stays on until it drops below a minimum level (the 60% mentioned above);
However, if I put the switch into position 2 (SOC O/R = Override) then the Heater has power regardless of the battery level;
And at position 1 (60m O/R), the SOC level is ignored for 60 minutes and then re-enabled. The idea of this option is that you can put it on the 60 minute override to give the water an initial heating session (the 850W will heat up the 10L of water to temp in just around 1 hour) and then don't have to remember to switch it off in order to save the battery power further, it is done for you.
(PS. I do have a separate switch to turn the heater on and off - the switch above just determine if the circuit itself has power by enabling an SSR - Solid State Relay. And if there is EHU present, the battery SOC is ignored automatically as power is provided by mains passthrough)

It may seem complicated, but it isn't really and combines programmed settings to maximize energy efficiency with manual overrides to maximize usability without having to start reprogramming anything :)
I guess I will be doing something like that once enough progress is made.
 

wildebus

Forum Member
I mentioned earlier I was trying a couple of new Lithiums, namely the Explorer Polarmax from Alpha Batteries.
Been a few weeks now since installation and I have to say I am pretty impressed with them.
They have delivered the power as expected, but what I really like is the way the batteries work with each other and also how the cells in the batteries work with each other.
The batteries use Canbus comms to talk to each other and I have a data cable between the two batteries (just a normal Cat5 RJ45 cable). Whenever I have checked the SOCs via the Phone App, they have been within a single percent of each other - for example....
Screenshot_20220612-105116.png

(the reason why the remaining time is different will be a fluctuating charge current from Solar between connecting to each battery).

So that is battery to battery sync. The other aspect is cell to cell within a battery. Followers of Will Prowse will be familiar with his comments about cell balancing. I can't recall what the general recommendation is in terms of closeness of voltage between cells, but this is what I am typically seeing via the app in terms of cell variance...
Screenshot_20220611-151548.png

A difference of 3mV between the higher and lowest cell voltages I would say is very impressive. The first part of this will be the battery manufacturer taking care with cell matching when building the batteries, and the second part will be the BMS keeping the cells in balance.

I'll need to decide whether to keep these batteries or put back the single Poweroad in the Motorhome (either way they will be working in a Hybrid setup with the Lead Carbons) :)
 

SquirrellCook

Forum Member
Allow the batteries to go into float for a day or so with 100% SOC I expect you’ll see a larger variance in the cell voltages.
 

wildebus

Forum Member
Allow the batteries to go into float for a day or so with 100% SOC I expect you’ll see a larger variance in the cell voltages.
Once back fully charged (solar been been for a few days so batteries low but looking ok now - getting around 200Wh/Hr at the moment) I will disconnect and see how they vary.
 

wildebus

Forum Member
Wildbus where or how did you make/get the switch stickers as to what they do, me want.
I make them on my 2D Plotter. Let me know what you want and I will do some for you. If they are to go on the switch plates you have shown previously, I have those and so can measure them up easily.
 

wildebus

Forum Member
Yesterday was the best day of the year for the Solar Harvesting :)

Using Victrons new Custom Widget which allows you to combine different devices on the same graph (can't set the axis's to the same scale but that is apparently coming) and see how they compare.
I have a set of 3 panels (270W) on the van roof, and a set of 3 panels (300W) on a shed roof (tilted slightly north which is not that handy :( ) and can see how they perform ....
The black line are the Van Panels and the Orange line is the Shed array (remember the scales are different - the orange is 0-100 whilst the black is 0-200 so just because orange is above doesn't make it greater).
Screenshot 2022-06-17 at 10-07-16 Monty - VRM Portal.png

What is interesting (I think, anyway) is how closely the two arrays track each other for the most part.
In the morning, the Roof array for sure wakes up better and that has got to be shade on the shed array as suddenly at around 9:15 it comes properly to life and then the two panels are in sync in their patterns.
Between 3 and 4 in the afternoon the van array perks up a bit - again likely a shade thing. In the past, around 2-4 PM was a disaster for the van solar but Storm Arwen fixed that by ripping up a big pine tree that was a major sunblock.
What is also interesting is that at no time does the 300W array on the shed roof reach the same power that the 270W array on the van roof does at that same time :unsure:
The van panels are flat and the shed panels are laying on the shed roof which has a slight pitch to the north, so that tilt could make a difference (I have just put them up there to use rather than actually installed them. If they were permenant, probably give them a good tilt to the south on a frame).
The van panels are in parallel whilst the shed panels are in series - supposedly that should benefit the shed panels but I am not sure if makes any real difference TBH - and the cable from shed to van is a lot longer (which is why I ran those in series).
And the final difference, which *could* be a factor, is the shed panels are standard budget glass panels - in this case Eco-Worthy brand; whereas the van panels are Victron Energy glass panels and from which I have seen >100% of the rated power coming in on occasion. I chose to use Victron panels on the van roof mainly because they had the right form-factor and I wouldn't have thought the performance to be significantly differently different, but maybe it is?

But both have been putting in some useful power. using the same combo-graphing (and again annoyinging scales are different) you can see how much power as the day progresses ...
Screenshot 2022-06-17 at 10-28-28 Monty - VRM Portal.png

The Roof Array (in Red) put in 1.19kWh and the Shed Array (blue) put in 0.74kWh so a total just short of 2kWh. The Roof is pretty well a straight line from 7AM until about 4PM when it starts to flatten a bit (had a dip in harvesting around what would usually be peak time of 1:30 to 2:30 due to cloud).
Anyway, interesting comparision day to any future ones. Right now I have around 70Ah to put back into the batteries, so the solar should do that today I would hope as well as provide the running power required.
 

MarkJ

Forum Member
I have seen >100% of the rated power coming in on occasion.
Funny you should say that. My domestic installation is new this year so it's getting it's first full roasting. Half the panels are south facing and half are west facing, so in theory there is never an optimum time of day for them, but there should be a fairly long day. However, I've seen well over 100% harvesting a couple of times now.

Manufacturers being conservative? Just a benefit of using quality stuff rather than cheap stuff?
 

wildebus

Forum Member
Allow the batteries to go into float for a day or so with 100% SOC I expect you’ll see a larger variance in the cell voltages.
So batteries fully charged a couple of days ago and disconnected from system so they are just sitting standalone (except with each other) and no load or charging going on ... (the Green Line is the LiFePO4 Lithium system)
Screenshot 2022-06-22 at 11-59-04 Monty - VRM Portal.png


Checked the cells on each battery this morning ...
Screenshot_20220622-094742.png
Screenshot_20220622-094817.png

Front Battery has cells between 3330mV to 3334mV (4mV variance over average of 3332mV)
Rear Battery has cells between 3325mV to 3330mV (5mV variance over average of 3327mV)
Immediately after the charging completed the cell variance was a bit larger (which is typical of batteries immediately just after a charge or load), but one of the key purposes of the BMS is, of course, cell balancing and that is evidently happening :)
 

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Pudsey Bear

Forum Member
I took delivery today of a very nice Autotrail Cheyenne 635SE :D

The Cheyenne is in superb condition so not a fixer-upper in the slightest, which is great, but I plan to make a few improvements still to make her even nicer (y)

A few pics just before we took ownership ...
View attachment 2925

Kitchen
View attachment 2928


Part of Bathroom
View attachment 2927

View attachment 2929


Plan to log the changes and possibly even do a youtube video series!
Very nice, I won't even go to look at a van now if it doesn't have that type of heater, so much better to have ambient heating than just blown air.
 

wildebus

Forum Member
Having a frustrating thing going on in the last month or so in the Motorhome ....

To recap the setup, I have a pair of Victron 100/20 MPPT Solar Controllers installed, one for the ROOF array and one for an EXTernal/portable array. I also have the Habitation electrics connected via the LOAD output of the EXT Controller (This allows monitoring of the load current and lets me see how much power is being consumed).

I installed a new Avtex Mobile Router setup in early August and started to find I was loosing connectivity randomly and did the usual of checking connections on the socket, etc. I then noticed I was losing power to the Motorhome Hab Electrics randomly (or so it seemed, anyway), which is why the Router was going off.
After a while I found there was a distinct pattern of when the power was going and when it was coming back. Looked like a timer type of thing but just couldn't get my head round it :( Everything seemed fine when I checked with my meter on the terminals of the devices.
Posted a question on the Victron Community Page, with a graph and description and someone there made a suggestion that made a lot of sense ....
This is what the graph of the Battery Terminals on the MPPTs looks like while I was having the problem. It was intermittant and random for a while before this, but below the problem has become consistant.
The Blue Line is the EXT Controller which provides the HAB electrics via the Load Terminals.
The Axe's are different even though it is the same battery connection because of the variance seen on the Blue line. And what this chap on the community forum spotted and I hadn't (wood for the trees?) is the voltage was dropping when the sun went down, and came back when the sun came up - so it was like there was no battery connection - and he thought blown fuse. You see the other MPPTs voltage tracking the Battery terminal reading.
1664135518650.png

Now what he said made sense and I thought he must be on the right path. But whenever I checked the readings manually, everything was right - the battery in and the load out, so what was going on?


Well ... I took it out and had a look under a magnifying lens just out of curiosity and found what I think was the problem ... dry joint on the Battery +ve terminal! This makes sense as it would explain the connection being lost, and also the physical action of putting the meter probes on the terminals will make the connection again, which is why it looked normal when I was testing it!

Being under warranty, I reported the device as faulty and so will be replaced. But if I had fixed it ;) this is what the result would be on a pair of MPPTs that have a common Battery supply source .... (now the Blue and Red lines are literally identical as they should be (I've included the voltage pop-up window to show we do have both lines in the graph, as the blue is just invisible sitting under the red) and my Hab electrics are no longer shutting off at night (y)
1664136627735.png
 

mb2tv

Forum Member
Good you have found it- dry joints are problematic to find!
Was it internal to the battery? Does not entice confidence in the battery.
 

wildebus

Forum Member
Something that has been bugging me for over a year got sorted today finally!

These are the lights I have on my Motorhome:

Original Lights Fitted by David, on Flickr

They seem ok, yeah? Well, they work, but they are quite untidy when you look at them a bit more closely
I cannot see any cracking anywhere, but the RHS light has let in water fairly significantly. This photo shows what that has done:

Old Lights by David, on Flickr
To the left of the dotted line, all the chrome finish has gone. You can see a bit of a 'water line' at the bottom of the different lenses. On the LHS Light, there is a nice growth of moss inside at the top of the Reflector, again due to water ingress no doubt.

Now the lights work. Never had any MOT issues on them but they just look untidy. I am also not a great fan of the "Lexus Light" look as these clear/chrome lights used to be called when they first came out on, well, a Lexus (IS200, I think?) and was a popular mod for Boy Racers on their Saxos and Corsas.

Decided to fix this once and for all with replacement slightly smoked but NON-Lexus versions

New Lights by David, on Flickr

Recap ...
Old on RHS:

Old Light by David, on Flickr
New on LHS:

New Light by David, on Flickr

And new lights in place:

New Lights Fitted by David, on Flickr


Just need to polish up the headlights now the rear end is looking refreshed!
 

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