[Validus]

Good evening to the community from Greece!

as many others I am in trouble in planning my electricity autonomy in my motorhome.
I recently purchased a 2014 Knaus Skytraveller 650DG based on a Fiat Ducato 2.3 130. The vehicle is Euro5.

I am planning to upgrade the electrical autonomy of my motorhome using a solar system. However, I am really concerned to protect every other part of the vehicle such the alternator.

My solar plan will be somehow the following: Mono solar panels around 300-350watt connected in parallel, 2 x 100-120 Ah AGM leisure batteries, MPPT controller, pure-sine inverter 500-700 watts.
The vehicle comes currently with an 80Ah leisure battery, which I assume is the factory one. The vehicle is currently charging its batteries either through the alternator or through 220V motorhome built in socket (not aware whether the 220V socket charges also the starter battery). I am not aware whether the alternator is a smart one or not.
My target is to install a system that the solar panels could also provide a maintenance charging current to the starter battery just to maintain a healthy state when vehicle is parked for some long time (e.g. a month). So far, I have been offered by local dealers (mainly motorhome dealers) with either the solution of a dual charge controller (EPSOLAR Duoracer) or with a relay from leisure battery to starter battery (like Cyrix from Victron energy). To be honest, I would like to go overall with Victron energy since they seem higher quality products, I am not clear though whether Cyrix is the optimum option. Appreciate your thoughts.
Here comes though my second concern. I 've read here and there regarding the risk of charging the leisure batteries through the alternator. Even more concerned while I am going to add extra load with in total 200-240 Ah leisure batteries, which is something that is not planned by factory. I am not really aware whether Knaus is using a B2B charger or just a relay to charge the leisure battery. Local dealers insist that the alternator will have no issue with extra load since it's constantly generating same amount of amperage (probably factory one generates 120-130 A). However, from what I have read on the web this is not correct. Appreciate here your arguments so as to be able to explain to the dealer. So I would like your thoughts whether a B2B charger is suggested to be installed in order to avoid damage on the alternator and the leisure batteries. Don't know whether I should consider to remove the factory method of charging (e.g. the relay) by installing a B2B charger.

Appreciate your comments since I have reached a point that even though I want to install a proper quality system I am willing to proceed with just a diesel power generator, instead of a solar system, due to the obstacles I have met from local dealers.

Cheers.

 

[jiwawa]

Welcome to the forum Validus. I can't help with your query but sometimes a post seems more visible when it has at least one answer so hopefully this does it for you!

I'm sure some members might be interested in picking your brains in the future about motorhoming in Greece!

 

[GMJ]

Yes and welcome from me too.

I cant answer either but my post will help keep your thread visible so hopefully someone will come along and see it.

 

[eurajohn]

Hiya, Do you know which make of habitation electric your van is fitted with? i.e. Schaudt, CBE, Nordelectrica etc.
If Schaudt (EBL) it will have the ability to charge the van battery as well as leisure.
For not a lot more money than 2 AGM's you could go for a lithium set up which will give you about the same useable energy with less weight and space required.
Your Euro 5 will be very unlikely to have a smart alternator, so unlikely to have a B2B fitted already, the Cyrix is a nice unit but effectively a "split charge relay" but would be useable as you require.
To enable your solar to maintain both leisure and van batteries the easiest way is use a controller that has that function although there are other solutions to that problem such as the Ablemail AMT 12-2 trickle charger.
If you were to choose the lithium route it would make good sense to fit a B2B.
Unfortunately if you are at the mercy of your local dealers you may have to go along with what they want to sell you

 

[Validus]

Hiya, Do you know which make of habitation electric your van is fitted with? i.e. Schaudt, CBE, Nordelectrica etc.
If Schaudt (EBL) it will have the ability to charge the van battery as well as leisure.
For not a lot more money than 2 AGM's you could go for a lithium set up which will give you about the same useable energy with less weight and space required.
Your Euro 5 will be very unlikely to have a smart alternator, so unlikely to have a B2B fitted already, the Cyrix is a nice unit but effectively a "split charge relay" but would be useable as you require.
To enable your solar to maintain both leisure and van batteries the easiest way is use a controller that has that function although there are other solutions to that problem such as the Ablemail AMT 12-2 trickle charger.
If you were to choose the lithium route it would make good sense to fit a B2B.
Unfortunately if you are at the mercy of your local dealers you may have to go along with what they want to sell you

Hi John,

Thanks for your comments!
To be honest I am not aware what's the make of the habitation electric of the motorhome. I don't even know how can I search for that (Knaus user's manual does not indicate anything). I will be receiving the vehicle by middle of Jan. However, I think currently the leisure batteries are getting charge from alternator through a relay (to be confirmed though).
The 200Ah AGM's or GEL cost about 400-700 euros, while a 100Ah lithium costs 600-700 euros. That's why I selected for now to go with either AGM or GEL (not yet decided which technology) and upgrade later when lithium become more cost friendly.
Cyrix was proposed from local dealer to use it for charging the starter battery from leisure battery. Considering though to go with either an EPEVER duo racer or with a Votronic MPP 350 Duo Dig since Victron Energy does not offer such combined solution.
I am mainly concerned though whether the 200Ah AGM/GEL batteries (instead of the factory 80Ah) could potentially heat up the generator and destroy it. As far as I understand B2B is a MUST when using lithium leisure batteries. Why is not a MUST when using AGM/GEL? What's the technical background here?

p.s. I am really considering to travel abroad to a country/service store that really has a lot of knowledge on this part in order install the proper system...

 

[Validus]

Welcome to the forum Validus. I can't help with your query but sometimes a post seems more visible when it has at least one answer so hopefully this does it for you!

I'm sure some members might be interested in picking your brains in the future about motorhoming in Greece!

Thanks jiwawa. Sure, I am pleased to help sharing my knowledge for traveling to Greece!!

 

[jiwawa]

p.s. I am really considering to travel abroad to a country/service store that really has a lot of knowledge on this part in order install the proper system...

Not so sure that's a great idea Validus - if anything goes wrong it's a long way to go to get it sorted.

 

[wfdTamar]

Hi from Australia (I have a Hymer in the UK). I have DIY installed solar using a Votronic DuoDigital (in my Hymer) and an Epever (in a caravan I have here in Australia). That's the brand of the EPSOLAR Duoracer. Votronic are German, Epever Chinese (and it shows in the manual and software).

First as Eurajohn says, you really need to know what electrics are fitted to the van now, before you start adding things, particularly batteries, but it can't hurt planning now. The vans electrics controller may have a limit on battery capacity or type.

Also as Eurajohn says, I'd go lithium now (if the electrics can handle it). You need to find out if the electric controller (the charger part of it) can do lithium. Far easier to change one battery than wire up a second. Also far greater lifetime cycle count which makes them cheaper in the long run. If not I would go quality Gel rather than AGM (though there are some other types I'd consider, like lead carbon).

Although it can't harm putting in the solar regardless of what you do about batteries. I would do that and see how you go with the existing 80Ah battery before changing that (unless it's knackered when you get the van). It will give you an idea of how much battery you need.

In my Hymer, as the standard leisure battery, I have a 100Ah Yuasa L36-EFB which seems quite a good lead acid battery type. When that dies I'll put in a quality gel (as it can be discharged further, so more usable Ah). In 2019 I installed 200 watts of solar through a Votronic DuoDigital controller (with the optional LCD display). I recently added a battery monitor (with a shunt) which is a great addition as it is a far better way to monitor battery use than voltage alone. That system kept the leisure and starter batteries charged during 3 winters (2.5 years) of covid lockup while I was stuck in Australia. It was all fine when I came over for this years summer (the mouse poo was another matter). I've had 2 summer trips of 4 months and it coped with my heavy power use (1 person) well.

This year, because I had to replace the dead fridge, I added a second leisure system just for the 240 volt compressor fridge (which replaced the dead 3 way one). That has 300 watts solar, Votronics DuoDigital controller (with LCD display & battery monitor with shunt), 100 Ah lithium battery, 30A B2B charger (with display), 500VA inverter (though I'm changing that to an 800VA). As it happens this system was bigger than needed, so it has extra capacity I can use for other things. I made it seperate so the fridge wouldn't flatten the main leisure battery and so there wouldn't be problems integrating it with the older Hymer electrics (a 2002 vehicle).

The caravan has 200 watts solar, Epever controller and 100Ah lithium battery with battery monitor & shunt.

Although the Votronic and Epever do the same thing (charge leisure and starter batteries) I prefer the Votronic as the Epever manual and software is not very good. The Votronic displays are nicer quality too (though expensive). Although the displays are optional, it gives you a good idea of how the solar is performing.

The other optional thing is a battery monitor that uses a shunt. The shunt is a device that connects to the battery negative terminal and can accurately measure how much power is going in and out of the battery. Without it the only way to assess battery is voltage which is not very accurate. The battery monitor gives you a percentage or Ah figure.

Over summer if I didn't drive, the solar recharged the batteries to full almost always. If I drove then the B2B charger worked at 30A for a short time recharging the fridge battery. It really works well. I don't think I saw it on 30A for more than 1 hour (and I doubt it would have been that long as I hardly used any fridge battery Ah). Might be worth seeing how hot the alternator is after that. It probably helps that any driving while it's doing that kind of charging is early in the day and right at the start of driving, so that would hopefully prevent it over heating.

I've read of the split charger systems (for passing some charge from leisure to starter battery), but not sure how they work. I didn't consider one as the solar does that job.

BTW - a beautiful clear sunny Christmas day of 26 yesterday, 32 expected today. That's Christmas in Australia (Tasmania, which is nowhere near as hot as mainland Australia).

 

[Validus]

Thanks for your enlightening feedback wfdTamar.
For sure I will need first to check what is the current plan of the Knaus' factory electronics. Just doing an early research on the market and the available solutions. By just goggling for "CBE Knaus" the results showed up a control panel which is very similar to the one currently installed on the vehicle. So, I assume it's currently having CBE electronics but this needs to be confirmed.

It would be a good idea to go first just with the existing battery and a solar system, in order to estimate what will be my needs, but I am afraid the results will be misleading since the current battery should be the one installed by factory, thus a 7 year old battery. Most probably will be at the last stage of its life.

For Votronic LCD display I guess you refer to this one, right ? And for battery monitor with shunt, is it this one ?

I will keep you posted once receive the vehicle and make the required checks.

Thanks again!

 

[wfdTamar]

Both those Votronic links go to their battery monitor with smart shunt. I didn’t use their battery monitor as I found a different brand that’s cheaper, but that may have been a mistake as it means I have a mix of components and the one I used (Renogy) counts faster in one direction than the other, so makes it seem the battery has lost capacity over time. Just means I have to reset it every few days.

I should have used the Votronic battery monitor as their displays are nice and clear and the same size, so looks neat if you have displays for multiple products (so I would have 2 solar, 1 B2B charger, 2 battery monitors). Also if you need tech support it helps if everything is the same brand, so the person answering your questions knows all the products and can't blame the other brand for the issue. For the same reason it might be wise to buy everything from the one place. I like to find a bargain and in Australia it's hard to find one source for everything, so I get things from all over (from here and in Europe). Sometimes a European product is cheaper in Australia (like Victron inverters).

As I'm installing myself it doesn't matter which products I use, but if you're paying someone else to install it might be wise to use the products they prefer, otherwise you're paying for their time to source and learn about the different brand. I would hope a good installer would give you options for quality/price. For example they might use Epever to save money, or Victron for quality. A lot of people like Victron products. I’ve used their chargers and inverters and they seem very good. If they have bluetooth to phone apps, the apps are good (unlike the Epever one). They have a big product range and they're well known which may be an advantage if ever you need it looked at.

I used the Votronic solar controllers (with optional temperature probe) with display & the B2B charger with display shown below. Some Votronic stuff is an ok price, but some is very expensive (aimed at the emergency vehicle market). They seem well designed, compact, with good manuals, though I did have one solar controller not work out of the box and a display had some discolouring.

VOTRONIC - MPP 250 Duo Dig.

Innovative Elektronik für den mobilen Einsatz

www.votronic.de

VOTRONIC - VCC 1212-30

Innovative Elektronik für den mobilen Einsatz

www.votronic.de

The battery monitor I used:

Server Busy

I used an MPP 250 Duo Digital for the 200 watts solar on my leisure system and an MPP 430 Duo Digital on the 300 watts solar for the fridge. The 430 has a small fan which does come on occasionally in full sun. You can hear it, but it doesn't last long. You may not want to mount it too close to where you might sit. If it gets hot enough to need a fan it's probably good it has one as it means the product will last longer than another brand that doesn't use a fan.

Another thing to consider is the displays and how bright they are. Can you turn off the backlight at night? Do they have flashing LED's? The Votronic solar controller flashes a green LED when the solar stops charging, all through the night. So I wouldn't place it where you can see it from bed. I find a little constant light (a few LED's) is ok (for a night light), but a lit display would be too much. You can turn the Votronic display backlight off.

 

[wfdTamar]

What is it you're planning to power that requires 2 x 120 ah AGM? I suppose it depends what time of year you travel too. I only do summer, so it's quite easy to manage with the Yuasa 100Ah L36-EFB (the main leisure battery). Plenty of hours of sun to recharge. I'm quite a heavy power user as I use a laptop, a 28" 240 volt TV (which I sometimes watch a lot), a 14" fan.

When I was investigating battery options I considered lead carbon ones which seem to be a poor man's lithium. Everything but the weight saving. I was going to get the Leoch.

https://www.alpha-batteries.co.uk/12v-100ah-ritar-agm-lead-carbon-ultra-deep-cycle-battery-dc12-100c/

https://www.alpha-batteries.co.uk/12v-leoch-pure-lead-carbon-plh-c100-deep-cycle-leisure-battery/

https://www.alpha-batteries.co.uk/12v-zap-batterien-100ah-carbon-efb-battery/

 

[Validus]

Hello again. So I received my motorhome few days ago and now it's time to proceed with the solar.
As I checked the current factory installation is using a charger CBE-516. The habitation battery is an AGM of 120Ah (no clue about its age) located under driver's seat, while the starter battery should be an 54Ah (need to remove the battery in order to check model, specs etc).
Current consumption as I am thinking will be:
1. Led lights
2. Truma heating
3. 12V TV (around 4 hours per day)
4. 2-3 mobile device charging
5. One or two laptops charging once or twice per day through 220 inverter

Found a dealer who has used before the Votronic equipment. Thus I am thinking to go with following setup

a. Two monocrystalic panels 140-150 watt each, connected in parallel,
b. MPP controller Votronic MPP 350 Duo digital
c. Solar monitor display Votronic LCD-Solar-Computer S
d. LCD battery monitor with smart-shunt Votronic LCD-Batterie-Computer 100 S (100A)
e. Pure sine inverter at around 500 watt either Votronic SMI-600 (no need of external switch since its monitor can be installed in an accessible place) or Victron-energy Phoenix Inverter VE.Direct 12/500 or 12/800 (need additional switch victron-energy switch to power off/on)
Note that the inverter will be connected to one or two new dedicated sockets.

As for the habitation we are thinking to keep as of now the existing one and monitor how it can support us compared to our needs. Most probably will need to replace with two new Gel batteries of 100-120 Ah each.

Appreciate your comments/suggestions.

Thanks,
Alex

 

[wfdTamar]

You need to consider the various ways to charge the battery and the charging profile (Lead Acid, Gel, AGM, Lithium) the equipment has before buying a leisure battery.
1. by driving - alternator through the main electrics box (which you have not shown yet so we don't know its charging profiles)),
2. by mains electric hook up (EHU) - the CBE 516 (that one does lead acid or Gel batteries),
3. by solar - the Votronic Duo Digital does any type of battery.

You don't list anything that will use very much power, so you should be ok with one battery, unless you think you'll do trips in winter (bad solar) and stay put for a lot of days (so not drive which recharges the battery) or not connect to EHU. Just pick a battery that can be discharged down to a low amount and lots of cycles.

Try to charge phones and laptops while driving or in the day from solar (stating the obvious). LED lights use hardly anything. The TV & heater fan are the only things that might use any significant amount.

Not sure if you know this (excuse if you do) - A typical lead acid battery should only be discharged to 50% to get 200 cycles. A lithium battery can be discharged quite a lot (maybe 80-90%) and still have 1000's of cycles. A cycle is from 100% down to its lowest % and back to 100%. The higher the % of the lower point, the more cycles it will have in its lifetime. So if you discharge a lead acid battery right down to 0% a few times you could kill it very quickly, but if you are careful and only go to 50% you should get the full count of cycles the manufacturer lists (maybe more).

AGM, Gel are between those two extremes, but there are newer types that are worth looking at too (if your electrics box and chargers can handle them).

You can roughly estimate the level of discharge by voltage (which differs depending on battery type), but a better way is a battery monitor.

The starter battery would likely be bigger than 54Ah. More like 75-90. That one looks quite clean and is a hefty 800CCA (its cranking power) so I'm guessing not the original.

That CBE 516 is only an EHU charger (converts 240V to 12V). That one does Lead Acid or Gel batteries (there's a switch inside you might check is on Gel). It is really not right for AGM. You might consider replacing it with a more modern one that can do the type of battery you choose (unless you do go for a Gel battery).

https://www.12voltplanet.co.uk/user/downloads/CBE%20Switch%20Mode%20Battery%20Charger%20instruction%20manual.pdf

Have a look at this site. Some of it is a bit dated, but still useful.

Battery Technology Advances mean big savings and better batteries for Caravans/Motorhomes

The best Leisure Battery is also one of the cheapest - Powerframe Varta LFD90 and Bosch L5. A Deep cycling and Starter battery in one.

www.aandncaravanservices.co.uk

The white box with big blue switches is the mains circuit breakers. The red switch is probably a battery isolator (a guess). The CBE DS 300 is a distribution box (from my googling) so there must be more electrics I think. I would expect there is another box that controls everything (all the 12V stuff). However I am not familiar with CBE. You just need to find that electrics box to determine what types of batteries it can handle and what capacity.

All that Votronics stuff looks fine. Their inverter is really nice, but I think crazy expensive. It has a display which will show if you've overloaded it. I used the Victron Phoenix ones which don't have a display, but they hum when overloaded and you can use any remote 12V switch (it doesn't have to be theirs). You can also get their special USB cable or bluetooth adaptor to read what it's doing on a computer or phone (and update its firmware). I ran my 28" 240V TV, or an E-bike charger, or MacBook Air charger off a 350VA one. A 500VA one ran my fridge (though it did get overloaded when the compressor starts). For your use the 500VA will be more than plenty.

If you decide to change the EHU charger, Victron are also good for that. I never need to use EHU as the solar or driving do all the recharging (but I don't use my van in winter or on paid camp grounds).

 

[Validus]

Thanks for your feedback wfdTamar. I will comment on your message, but meanwhile where else could I look for the electronics box for charging from alternator to the habitation battery? As of now, I have looked under driver's seat and under the leaving room seat. What I have noticed is that the control panel of the CBE (PC220-KN) shows a symbol of paralleling the batteries when engine is running.

 

[eurajohn]

The CBE system is not normally all in one central unit like the Schaudt units are.
From the rather murky picture above, the distribution unit (with all fuses) appears to be top right, depending on the van converter they will have situated any other parts wherever they could find space, the only van I've owned with CBE was a Carthago and the "add on" parts were in the double floor area with access via a hatch.

 

[Validus]

I think normally I should be looking for a relay between the starter battery and leisure battery. I doubt that it has a B2B charger in between. As far as I could see there was a red cable from starter bat going underneath the driver's seat where the leisure battery is located. But the leisure battery has a blue cable connected which I assumed (probably incorrectly) goes to the CBE. But somehow the control panel of the CBE "realizes" when the two batteries are paralleling (engine is running thus alternator charges starter and starter the leisure). Need actually to remove driver's seat in order to have a better view.

 

[eurajohn]

Possibly one of these Link here when page opens click on one of the 4 numbers for description and picture , might help identify if you have one of those.

 

[Validus]

Possibly one of these Link here when page opens click on one of the 4 numbers for description and picture , might help identify if you have one of those.

Ok, thanks. I will try to look for one of those.

 

[wfdTamar]

I think you have found it all. I found the manual for the control panel which lists all the components in the system. It looks like it only has the control panel (PC220-KN), EHU charger (CB516) and distribution box (DS 300). I was expecting something bigger (like mine), but your van is much newer than mine (dated 2002) so they have reduced the size of the electronics.

The red cable from the starter battery must go to the control panel connection (B1+), then the blue cable from leisure battery to control panel (B2+).

If this is the correct manual for yours it has a 20A fuse for solar input, so you could size your solar system to that (I'm not sure what size that would allow, but I think pretty small). It says when the EHU charger is charging it gives 2A to the starter battery, but priority is given to the leisure battery). Not clear if the same applies to solar input.

In the English section it uses the term 'Masse' for earth (or ground) - meaning negative. Also refers to the control panel as the 'watch'.

CBE pc220 User Manual [Page 15] - Control Panel - ManualsLibhttps://www.manualslib.com › ... › pc220 › User manual

Here are the components of your system. I can't find the manuals on their site.

PC220 -

Sistema completo con LCD

www.cbe.it

If you look at the charger section in this CBE catalogue it says you need the CB516-3 to be able to properly charge an AGM battery (the CB516 only does lead acid or gel).

https://www.cbe.it/wp-content/uploads/2020/02/Catalogo-CBE-2020-21-EN.pdf

So either change the battery to Gel, or change the charger. I'd change the battery. I'd get either this (well known and gives 64Ah usable):

https://www.alpha-batteries.co.uk/80-ah-exide-g80-gel-deep-cycle-leisure-battery/

or better still one of these (remember you need one that fits and has the connections where the cables can go on). The 110Ah gives 88Ah usable :

https://www.alpha-batteries.co.uk/leisure-batteries/?filter_ab_construction=lead-carbon-gel

 

[wfdTamar]

'What I have noticed is that the control panel of the CBE (PC220-KN) shows a symbol of paralleling the batteries when engine is running.'

That's good, it's showing that it's linking the starter battery to the leisure battery, so recharging it. Try measuring the leisure battery voltage with the engine off (should be somewhere in the 12 volts if it's healthy). With the engine running (if it needs to charge the battery) it should be 13+.

If it's not showing 13+ volts when engine is on either:
1. battery is charged, so it cut the charging off,
2. charging is not working (check fuses & connections),
3. cable from starter battery-control panel, control panel-leisure battery is undersized and you're getting voltage drop.