Beiträge von Cordy

Just the final info: I have finished all the activities. And used the van for summer holidays: 9 days and 2.200 km (approximately), without any single problem. I did not need to charge the batteries. I love the very basic concepts that has been used by Carthago.

Gas: two very simple, very easy to find Campingaz gas bottles. It's expensive, nowadays, but I hope it will be better soon. I found spares in Bad Toelz, in Stuttgart, but it's easily available nearly anywhere in Europe. And the gas connection is standard, so you can simply leave the empty and take away the full bottle.

Water: two plastic bottles, each approximately 20 l. You can fill them anywhere there's a tap. No need for pipelines, adapters...

Electricity: there's nearly no power consumption in the van. So, a 70 Ah is still full after 3 days steady somewhere. And in a few kilometers (now...) it's fully charged.

On a single phrase: easy, lightweight, with days of self-sustainable storage of everything you may need.

I have finished the job: now, it works fine, for my need. What I did is... well, totally redesign the electrical system of the van. Scrapped (as I have already mentioned) the original battery charger, because it was melted. Now, I have scrapped also the EZ 90. Because it's made in iron and I don't like the idea of 230 V in a metal box, together with the 12 V connections.

So: totally rewired the 230 V part of the system, installing the original safety switch (10 mA ABB differential and thermal-magnetic 6 A automatic switch) in a plastic box (IP44).

A new (Victron) battery charger, which is also perfect the keep the battery in a good shape when the van is left unused for a long time in the garage. It can be left on, since it's a good iUO battery charger, but works fine as a battery maintainer (IP67).

I have scrapped all the plugs that connect to the original EZ90, switching to a different approach. A multi-pole connection system, coupled with a 6 places fuse box. On these two components I have re-wired and re-coupled with faston plugs all the users: pump, pump switch, 3 neon lights, Truma heater, fridge ventilator, the panel that shows water levels as well as battery levels.

Moreover, I have modified the fridge, to get it on only when the engine is on, adding a parallelator relais.

The battery charger and the inverter (yes, I added a 600 W inverter...) are directly connected to the battery, with a dedicated fuse on each line.

The final touch, is a Victron parallelator relais, that is microprocessor controlled, to connect engine and service batteries. The fridge is connected to the engine battery.

I need to add some order now, because the wiring is still in a provisional situation, to check if it works fine (yes, it does!!!).

I also want to add a midi fuse box at the beginning and at the end of the wire that parallels the two batteries, but I'll ask a workshop to do it: the wire is too thick, for my tools, to have a good mechanical connection: it's better to use an hydraulic clamp and it's too expensive, to buy it for 4 connections...

One extra bonus: the Victron parallelator works both ways. I.e.: when I switch the engine on, if the service battery is substantially less charge than the engine battery, it goes on. But, also, when I connect the Van to the electricity in the garage or in a camping, if the engine battery has less charge than the service battery, it goes on as well.

I'm still wondering if I ought to add a battery protect, but I didn't find the right spot to place it. It must be in a very well ventilated area, not hot, not on top of the battery, not beyond 50 cm from the positive pole of the battery. There's no space conforming to all these requirements, in the van, unfortunately...

If you have any hint or questions, feel free to ask. Bye Bye. Stefano

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This is the diagram of the inner circuit of the fridge. It was hard to believe, but it works exactly as I have supposed to: it is directly connecting to the service battery. I have installed a fuse that disconnects the resistance once the engine is off. I.e. I modified the inner circuit.

But I didn't solve the problem, apparently: the battery is not being charged if the fridge is on 12 V. I presume the line is not enough strong to support a 10 A consumption from the fridge AND to charge the second battery.

Moreover the EZ90 does not provide a reliable connection. I am now thinking whether I ought to send it to Schaudt (long time and presumably a significant cost) or I ought to change the whole circuit of the van, installing a new fuse box, dc-dc charger, earth bar, and eventually a BMS (with a lythium battery?).

Did anybody do this?

A radically new and more up-to-date wiring is more expensive. And, what's the most to me, not respecting the originality of the vehicle. It's a 30-years old van, only 4 of them are still alive, in Italy, so it also has a collector's value, not to be underestimated. I don't know... what would you do?

This is it, after restoration:

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This is the space behind the fridge. My plan, now, is to add a relays, activated by the yellow line (D+), to interrupt the direct connection to the van battery.

I could connect the fridge to the engine battery, instead. Or, add a new D+ line, with a large wire, to feed directly the fridge. But, with this kind of connection the fridge works very well also with 12 V power supply, so my plan is to avoid accidental discharge of the van battery and use for a while the van with this modification. If everything is OK, or if not, I'll come back with the results of my test and measures.

Another thing I'll add are fuses: one in the engine compartment, near the engine battery, to protect the white line that goes to the EZ-90. In case of crash or any other kind of problem, it is a good protection. Based on the actual size of the wire, I presume a 10 A fuse ought to be OK. I'm going to make some measures, to check if there are some spikes of current that might blow a 10 A fuse. Again, I'll keep you informed.

A similar, 20 A fuse will be installed on the yellow line, that's starting from the fuse compartment, on the left side of the steering wheel.

An identical fuse protection will be installed before the EZ-90 on the two above mentioned lines. I presume that EZ-90 has fuse protection inside, but I want to be sure that the fuse is working before the plugs and prongs shown in these 3 pages may melt.

Is there something wrong in my "project"?

Some more info and pictures. This is the inside of the van, with the two rear seats removed. I must partly correct myself: the wires are:

two, red, two lines each, for the rear cabinet loudspeakers

one, white, that carries the engine battery voltage to the EZ90 and

one, yellow, that is the "D+", or the alternator charger line.

As you can see in the picture, they are kept in place with the wrong tool: a metal, blade-sharp edges, fixing object. I have removed it from and added a lot of isolation in that place to the wires. As you can see, the wires are of the exact length, non a mm more, so, they could easily short. Moreover, the black pipe is the exit of water, to the waste water compartment: there could be some water, there.20220305_092706.jpg

A quick update. The van is now in a workshop, to professionally fix some bumps and scratches. I also asked to restore the base of the two rear seats, because it's very rusty. So, I could see the inside of the van without the two benches and... surprise! On the left side of the van, two red and a white wire are running from the front to the rear of the living compartment. They are short, with a system used to keep them in place that's... uhm... how can I politely say? To be changed. They are also quite thin, if I correctly understand the meaning: D+ (white?), Engine battery (on of the red lines) and van battery (the other red line). As a minimum, I'll add a double fuse (one on each side of the lines, because when the parallel is on the short circuit might happen in both ways) and thicken the wires; which is your suggestion? 16 mm² ?

Hi from Italy. Sorry I don't speak German, I hope English is ok. Thanks to malibujogi who invited me here. Here's my van:

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This morning I had one spare hour to go to the van and start doing some checks. Unfortunately, very soon it was raining, so I couldn't make any test with engine on.

But one thing is now evident: the fridge is directly connected to the second battery and not to the alternator, after a bypass relay managed by the "engine on" line.

This simple fact explains all my problems, together with the broken parallelator relay.

A few extra info for... well, anybody looking for information on this quite rare van (Carthago Malibu 31, year 1992):

- the fridge, if the unit installed in my van is the original, is pumping away nearly 10 A DC.

- the original charger/power supply is a 7 A unit.

- The biggest AGM battery that can fit in that little space is, nowadays, a 70 Ah.

I need to investigate further more, because:

1. it looks like the two batteries are in parallel if the engine is on (and that's right) AND ALSO (with engine off, of course) if the external 230 V power line is on. And this, is strange, as a minimum. I need to better check this out, when it will be possible to stay outside the garage, measuring all the voltages with engine on and off. But it looks like the "emergency button" is always pressed. With "emergency button" I mean the "NOTSTART FUER LADER" button, that I presume, looking to the scheme, is performing that function, inside the EZ90.

2. Considering point 1 and the quick check I did on parallel relay (with engine on, voltage goes up to 14.something volt... on battery 2), I'd like to understand if the alternator is supplying energy to bat2, with engine and fridge on. And, possibly, how much energy.

In one word: I'm confused, even more than before... more to follow.

Uhm. Yes, of course I measure the battery voltage directly at the poles. And that seems double strange to me, because the fridge ought to be directly linked at the alternator (or to the engine battery). It looks like the fridge is pulling down the parallel between the two batteries. Maybe the internal circuit has some problems, too.

I was thinking about the whole matter in the last days. Maybe the fridge connection has a problem, or: the alternator has a problem!

In any case, I have finally decided to buy a clamping amperometer: I'm awaiting to have it, to make some measures, to understand in a better detail what's happening.

I'll come back with more details in a few days.

Meanwhile, I'm also thinking about a "new creation": my own version of the EZ90. Based on a Arduino-something nanocomputer, to overcome all these small problems. I don't know if I have enough time to project engineer and maufacture it, that's the key question!

Last sunday I could reinstall the EZ90 and test it. Now, with engine on, the voltage on the 2nd battery is 14,64 V which is good, afaik.

The new 230 V charger also works fine.

I have seen a new "problem": if I switch the fridge on at 12 V, the voltage on the 2nd battery goes down to 13,45 V, which is low, considering that the two batteries are charged at 100%. Uhm...

Do you have any hint or suggestion?

This is "the fuse". Or, better: the connection on the (broken) PCB from the internal trennrelais, contact 30, to the distribution of battery 2 positive. As you can see, I have added a copper wire, soldering everything in a thicker connection. A new trennrelais, with temperature protection (a so-called "R-relais") with double the intensity of the original (from 20 to 40 A) is the other fix, for the moment.

I am planning to cover everything with rubber, to avoid any contact of the thicker soldering with the metal cover of the EZ90 and to add a good fuse on both sides of the battery lines, in order to avoid any danger of fire.

Unfortunately, on my Malibu 31.1 all the wires connected to B1 (engine battery) are red. So, I'll need to understand which is the right one, to install a fuse on it.

If you have any hint, it's welcome! Bye bye - Stefano

In the first picture, the MATE-N-LOCK connection and wires of 12 V section of the charger, melted.

in the second picture, the earth wire of the 230 V connection inside the battery charger totally "cooked".

Sorry, I am Italian, so I'll write in English. Let me say thank you to all the people that has placed here informations, pictures, problems and solutions.

I have a similar problem with my Carthago Malibu 31.1 first registered in Germany in 1992.

I have bought it in Italy in May and it was left unused in a closed garage since 2013. The two batteries were both flat (0 volt...) and the tyres too.

So, I towed it away with a truck and made some basic maintenance (belts, fluids, filters...). Everything works fine, in the mechanical part of the vehicle.

In the rear, I first detected a problem with the power supply: the 230V power cord was melted. After disinstalling the EZ90 and the power supply/7A battery charger, I could understand that the transformer inside the power supply was short to ground. So, the current of the second battery was free to run from positive of the 12V side of the power supply, to the ground of the 230 V side of the same power supply. This totally melted the isolation of the cable, damaging so much the system that it surely was stupid to try to repair it.

So, I scrapped the original battery charger in favour of a more modern unit, a Victron IP 67 7 A 12 V battery charger. I also scrapped the MATE-N-LOK pronge and plug in favour of a direct connection.

So, this was the first repair. I spent 10 days during summer holidays with this setup and it works fine. Everything in the van works fine, except the parallelator.

So, I disinstalled again the EZ 90 to understand what's wrong.

As far as I can understand, the printed circuit board that connects the D+ to the "TRENN RELAIS" is too thin. I have added some copper and soldered it. Another thing: I'm going to exchange both the relais added in the relais and fuse box on the left of the pedals of the driving place and inside the EZ90 (the TRENN-RELAIS, not the fridge relais: this is soldered on the PCB but works perfectly fine).

Moreover, I have added a couple of ECE-ONU plug-pronge on the 230 V cables that go inside and outside the EZ 90, for two reasons:

1. to be able to disinstall quickly the EZ 90: working on it inside the van is... well, impossible, because I'm too big for that space and...

2. to be able to restore a minimum functionality if the 230 V of the EZ 90 fails. I could simply bypass a part of the electrical system, in case of emergency.

Here's a picture of how it looks like now, in between of these activities: