What is an EBL? All about the Elektroblock - in detail.

The EBL is a box fitted to later post 95 (approx) classic Hymers which handles all of the habitation electrics.

Earlier pre 95 vans have separate components - ie fuse box, relays and mains charger, but the later vans have all this incorporated into one box - the EBL.

So an EBL contains a 230v charger, split charge relays and 12v habitation distribution and fusing. It is connected to both the engine battery (EB) and the leisure battery (LB), to the alternator D+ signal cable, to the fridge for 12v fridge operation and to the various habitation circuits - lights, pumps etc. The EBL is also responsible for driving the control panel, where the meters are etc.

It also has a socket into which a solar controller can be connected - but there are limits to what con be connected here - see below.

At first glance it looks a complicated beast, with a whole plate of spaghetti on the front of it. But you only have to study it for a while and you will discover that it has typically efficient German design and common sense going on. All you have to do is learn a few new words - "block" and "pin".

All the cables are connected to the EBL via multi connectors - these are called "mate n lok"  - it's a brand name. These are good connectors, but the downside for the amateur is that you need special tools to attach the pins to the cable ends, and then the pins push into the holes and have a tang which locks them into place. This means they can't easily be taken out - you need a special tool. However the good news is that the average owner rarely needs to do this - modifications and repairs can usually be made without special tools or pin removal.

The sockets on the EBL are called "blocks", and they are lettered - A B C etc. And within each block, the pins are numbered. if you look closely you will see that the pins are numbered in such a way as you can work out which pin is what. So for example Block A may be a 3 x 5 block - the lower left hand pin will be numbered 1, the end of the row will be numbered 3, and the top right is 15. So that is telling you the numbering scheme - start at one and count across in rows. So if you want pin 7, that will be third row up, first pin .... all very logical.

So when you are talking technical with EBLs, you will often see - Block A pin 7.

All the EBL models are made by a company in Germany called Schaudt, and they are used in many other vans - not just Hymers - and all the technical manuals and diagrams are available online. The diagrams show the function of each pin.

So looking at this diag you can see that Battery 2 positive - the leisure battery - is connected to Block C pin 2 .... and if you look closely, you can see that pin 2 is also paralleled with pin 5 - this is common in EBLs to allow more current carrying capacity. Note this is an example and does not mean that all EBLs have the LB connected to these pins.

So now you know how to identify the connections on your EBL - but remember that there are several models of EBL - EBL99, EBL104 and EBL105 are common ones, but there are others - but the principles are the same for all.

So now let's look at some of the functions of the EBL.

230v Charging.

All EBLs have a 230v connection. This is to power the internal charger. There is usually a switch on the EBL marked on/off and this switches on and off the 230v supply to the charger. usually it is left on, and so when the van is plugged in to EHU, the charger is live and delivering 12v charge to the battery.

It is important to remember that the EBL has nothing to do with 230v distribution to the 230v sockets around the van. The sockets are fed directly from the EHU connection, via the breaker box (consumer unit), and the EBL also takes its 230v power from here also. The switch on the EBL only affects the charger.

Most classic EBLs only charge the leisure battery, but some also charge the engine battery as well. You have to consult the documentation to see if your EBL has this function.

The other thing you have to remember is that even when you are plugged in to EHU, everything in the van, except the 230v sockets, is still powered from the LB. All the lights and pumps etc are powered from the LB, and the EBL charger replaces the battery power used as you go. This means that if the EBL charger fails, or is switched off, you can still end up in a situation where the LB goes flat and the lights go out even if you are plugged in - although this is a rare situation, it can cause confusion. The EBL does not provide 12v power directly to the van - it just replaces the battery power used in real time, and any left over goes to top up the LB.

Engine charging

The EBL is also connected to the engine battery (EB). And of course the EB is connected to the alternator - and the alternator charges the EB. But of course when you are driving you want the LB to be charged as well. This is achieved by relays inside the EBL. Relays are the same as switches. 

All alternators have a signal line called the D+. This is the same signal line that operates the red battery light on the dashboard instruments of your van. When the engine is on, the alternator is spinning, and the D+ line goes to +12v. This D+ 12v is used to switch on the relays inside the EBL. So when the engine is on, the relays are operated and the two batteries - EB and LB are connected together - in parallel - and this allows alternator power to flow to both batteries while engine is on. As soon as the engine is switched off, the relays switch off, and the LB is no longer connected to the EB. This arrangement is traditionally called a split charge relay system and is common to all motorhomes and caravans. The reason it is done this way, with relays, is so that the LB can go flat while the van is parked, but the EB always stays fully charged so that the van engine will always start.

You can see this in action by looking at the meters - the voltage on both batteries will rise to the same level - above 13v, with the engine on, and the relays are working properly. 

Fridge on 12v

The same system is used to power the fridge on 12v while driving - assuming you have switched the fridge to this mode. A typical fridge takes 10 amps on 12v, which would soon flatten a leisure battery, but is no problem to an alternator, so the fridge is only allowed to run on 12v while the engine is running.

Fusing

There is a big row of fuses on all EBLs - and the function of each fuse is written on the EBL next to each fuse. They vary from van to van, but basically all the habitation circuits - ie everything in the living side of the van is fed from the cables on the EBL, and all are fused. So if something stops working, these fuses are the first place to look.

Metering

Because both batteries and all the hab circuits are connected to the EBL, it is logical for the control panel to also be connected to the EBL. The voltage and power meters are fed by a multi core cable from the EBL to the panel. On some vans there is a master 12v on/off switch on the panel - this operates another relay switch inside the EBL which switches on or off main 12v power to the van hab circuits.

Solar

Solar and the EBL confuses a lot of people. There is a socket (block) on the EBL marked "solar". This is to connect solar controllers into the EBL, but the only solar controllers that plug straight into this socket are those made by Schaudt, and another German company Votronic. These are PWM controllers - which are now regarded as old technology - don't forget that the basic design of everything electrical in a classic Hymer is 1980s and 90s technology. Back then solar was expensive, and much less powerful than today. Most EBL manuals state that the maximum solar power that can be plugged into the EBL is around 10 amps - roughly equivalent to a 100 or 150w solar panel. 

But these days solar panels are much more powerful - 200w and above, and more efficient MPPT controllers have replaced the older PWM controllers, so if modern or upgraded solar is fitted to a van with an EBL it is normal to not use the solar input on the EBL and to connect solar controllers directly to the battery.

Upgrades and bigger batteries.

So what does a modern classic owner do when they want to install bigger batteries, bigger solar panels or bigger chargers to a van that has an EBL?

The simple answer is to connect all of these more powerful components directly to the leisure batteries and to disable all functions of the EBL except for 12v power distribution and fusing.

230v charger upgrade

If fitting a newer bigger charger, then all you have to do is unplug the 230v plug from the EBL - this will disable the internal charger. Then connect the new charger directly to the LB.

Solar upgrade

The same goes for solar - ignore the solar input on the EBL and connect your new panels and MPPT controllers dire tly to the LB.

Engine charging upgrade

If you are fitting bigger leisure batteries and need more charge from your alternator, then things start to get a bit more complicated.  A lead acid battery will take charge at roughly 20% of its rated capacity - so a 100ah battery will take 20a - a 200ah battery will take 40a, and so on. But most EBLs were only designed for 100ah batteries (occasionally 200ah) so the relays and cable sizes are too small to handle more alternator power.

And if you are fitting lithium batteries this is even more important.

So the split charge relay system inside the EBL has to be disabled and new bigger cabling and more powerful external split charge relays have to be fitted externally. Or in some cases a relay is not used, and a b2b - battery to battery charger - may also be installed.

The easiest way to disable the split charge relays in the EBL is to simply cut the D+ alternator line to the EBL - usually a yellow wire. This will then stop the internal relays from operating. However this will also stop the fridge relay from operating, so just cutting the D+ line also disable the 12v supply to the fridge while driving. 

If it is important to preserve this function then there are several ways - either the internal split charge relays can be disabled - this means opening the EBL and going inside, so is only for owners with this competence. Or, an external fridge relay can be fitted. This external relay would be operated by an extension to the D+ line, and the new relay would be connected to the branch from the incoming EB line to the EBL, and the 12v feed to the fridge from the EBL would be removed from its plug, and connected to the output of the new relay, via an inline fuse. This sounds more complicated than it is but is achievable with basic 12v wiring skills.

Other possibilities are to run the fridge on gas while driving, or even run the fridge on 230v via an inverter.

And finally ...

So that covers most aspects of EBL modification. There are now many vans with EBLs on the road sporting big solar and chargers and lithium batteries where the EBL is only used for 12v fusing and distribution, and all other functions have been bypassed.

Differences between pre 95 and post 95 classics.

Or to put it another way - differences between EBL vans and non EBL vans. Non EBL vans have basically the same functionality, but it is in separate components, not just in one box. So the early vans have a separate fuse panel, and the relays are in a box behind that panel. They also have a separate 230v charger. If an early van has solar, then it is always connected directly to the LB.

Final notes

I have not mentioned shunts in this article - shunts are quite a technical subject, but for the sake of completeness, all EBLs contain a shunt, and it is the shunt that estimates current flow, and displays that info on the power meter on the panel - usually called the "STROM" meter - German for power. 

More info

There are 2 firms in the UK that specialise in EBL repair

They are Apuljack Engineering and A & N Caravan Services

Both come up on google first page.

The A & N web site is a mine of information on EBLs, but is not for the faint hearted - the author uses technical language and assumes that the reader has the same.

For more info and discussion, join and ask on the Classic Hymers Technical Facebook group.

https://www.facebook.com/groups/297054424534823

Lithium in the Classic Hymer

Too busy for a long article? Can you just “drop in” a lithium battery into an unmodified classic Hymer? Basically yes you can, as long as you keep an eye on it, and the best way to do this is to choose a "smart" lithium battery that comes with a bluetooth app for your phone or tablet that shows you exactly what is happening to the battery in real time. Then you are in control. There is really no point in installing a "dumb" lithium battery - unless you are quite technical and have other means of monitoring and testing.

For the technical discussion .... read on.

Can you just “drop in” a lithium battery into an unmodified classic Hymer? I am afraid that there is no definitive black and white answer. I asked 3 leading lithium leisure battery manufacturers this question. One said yes, the other said their advice was to always fit a battery to battery charger, and the other didn’t reply!
So lets take each of these charging sources in turn, and try and assess their suitability for charging lithium.

The main issue is that lithium has different charging parameters to normal batteries, and the implied danger is that charging devices might get overworked, because a lithium battery can usually take all the charge presented to it. This could result, for example, in components only originally designed for charging a standard 100ah leisure battery with around 20a of charge, to deliver much more than that when a lithium battery is installed.

Alternator charging

The standard pre 95 classic, Fiat or Merc has an alternator of around 50 to 70a, and cabling between the engine battery and the leisure battery, via the split charge relay behind the fuse panel, of around 10mm2 copper, and intended to handle around 20a. Hymer fitted a 70a relay, but it is important to remember that this was over specification by Hymer so that the relay would last for ever - not to actually handle 70a.  But the bottom line here is that you are starting with a charging circuit with a design capacity of around 20a. But this isn’t self regulating - it doesn’t limit itself automatically - if asked to do more, it will, but then every component in the chain of the circuit will be working harder than before and problems can occur. In practice, if an original charging circuit is used, then it needs to be monitored for the first few weeks and months. The limiting factor is usually cable thickness, but connections can also be a problem, especially old ones that may be corroded or tired.

But some owners can and do charge lithium directly from the alternator - by upgrading cables and relays. Bt these owners are usually technically minded, and have metering and monitoring in place to ensure that every component in the chain is solid, and that the alternator isn’t being asked to work too hard. You have to keep and eye on it, and have the metering in place to monitor it.

The other worry that you read about online is that a charging system designed for lead acid batts is not suitable for lithium. This is actually not really a problem. A lead acid charging circuit will deliver around 13.8v maybe a bit more. But the limit for lithium is 14.6v, and even if this voltage was reached for some reason, the lithium bat's BMS would kick in and disconnect the charge. And if you look at the cgarge vs voltage chart for lithium batts you will see that even a charge that goes no higher than 13.8v will still result in a 95% charge. And in practice, with most vans that have lithium will also have solar, with a solar controller that has a lithium profile, solar will take care of the remaining 5%.

What many forget is that lithium batts are not dumb like lead acid, they have brains - the BMS, Battery Management System, and the job of the BMS is to prevent abuse. So the BMS will simply switch off the battery if the voltage or current falls outside of preset safety values. So in reality it is actually almost impossible to damage a lithium batt - touch wood!

But when it comes to alternator charging the simple solution for most owners is to fit a battery to battery charger - a b2b. This is a device that sits between the engine battery and the leisure battery. It has two main functions - to limit the amount of strain put on the alternator, and to present the leisure battery with a near perfect charging profile. A b2b is easy to fit - it has just 3 connections - to the engine battery, to the leisure battery, and the D+ alternator control line. (some b2bs don’t even need D+ - they are auto sensing). The only other issue for classic Hymer owners when fitting a b2b is that the original Hymer split charge relay (discussed above) needs disabling. This is easily done by removing the original relay from the fuse box. All other original cabling is left intact, which preserves the original function of 12v fridge operation while driving. Then a new cable has to be installed from the engine battery to the b2b, and from the b2b to the new lithium battery. The size of this cable is dictated by the size of the chosen b2b. And the size of the b2b is dictated not by the size of the new battery, but by the max rating of the alternator. The general sensible rule is 50% of the alternator rating.

If fitting a b2b which needs D+ switching, then the original D+ line to the original relays in the fuse box has to be identified and tapped into, and a new wire run to the b2b.

In the case of classic Fiat vans, where the engine battery is under the front bonnet, a longer cable to the b2b is usually needed, and the D+ line can be run alongside it - the original D+ wire is usually able to be found in the area of the engine battery.

In the case of classic Mercedes, with the double battery box next to the drivers seat access is easier - the b2b can be easily connected to the engine battery and from there to wherever the new lithium battery is located. An easy way to obtain a D+ signal in the Mercedes battery box is to open the trunking that leads across the bottom edge of the door (if fitted) and locate the 12v power feed to the fridge, and carefully split the cable and tap into the fridge feed. The 12v fridge feed is relay switched by the D+ in the fuse box, so is in itself a D+ proxy - this method just makes it easier.

The other factor that needs thinking about when considering alternator charging, is just how much you want. There is a trend with lithium batteries to “go large” and fit batteries of 200ah or more. So you have to think about just how much driving time you will need the next day, in addition to whatever you get from solar, to replace the power you have recently used. With most classics having around 60 to 80 amp alternators, and a sensible limit of around 50% of this, then that means no more than about 30 to 40 amps per hour of driving will be available. This is usually enough for most owners, but if you want more, then the only alternative is to fit a bigger alternator. But before you do, consider this ...

Solar keeps working all the time, and many vans with lithium also have solar, and those that don't should have! And modrrn solar panels are big, and cheap. In 2024 you can get a 425w black panel that is 1700 x 1100mm and will fit perfectly on the front of most Hymer roofs. And if you have such a panel, or even 2 or 300 watts of other panels further back - these panels don't stop working while you are driving. On a sunny day in summer I have regularly seen 70a of charge while driving - 40a from the alternator and another 30 from the solar! So factor in your solar ad your driving habits (winter/summer) before you go to the expense and hassle of a bigger alternator

EHU (230v) charging - and the EBL ...

This is another grey area - similar to alternator charging. A standard lead acid charger will charge a lithium battery no problem. But in doing so it will be working at 100% until the battery is full - assuming the cabling will pass the full charge. So again, monitoring is important. This is especially true with later vans that have an Electroblock - EBL. An EBL contains a 230v charger and relays that allow alternator charging through to the leisure battery and the fridge. It also contains the 12v fused distribution to the van’s habitation circuits.

Earlier pre 95 vans don't have an EBL, and have a separate charger. Most owners have replaced the original separate charger, so what charger you now have dictates what mods if any are needed. The original factory charger, if you still have it, will give some charge, but not much.

If you have an EBL and are fitting a big lithium battery - 200ah or more, then the easiest way is to disable both the charger and the relays in the EBL, and just use the EBL for distribution. On most EBLs this is easily done - just unplug the 230v plug, and cut the yellow D+ wire from the alternator that operates the relays. Alternatively you can just remove 230v, and also the main battery cable from the engine battery and redirect the battery cable to your B2B. But both these methods mean that the 12v feed to the fridge while driving is also disabled. There are several scenarios to deal with this. If you want to retain this feature then you have to go inside the EBL and disable the main relay, but keep the fridge relay. How you do this depends on the model of the EBL. Another method is to disconnect both the D+ line, and the fridge 12v feed wire from the front of the EBL, and mount an external relay. Or you can just forget about running the fridge on 12v when driving, and run it on 230v while driving. Most owners who fit lithium will also have an inverter - you can connect the fridge 230v cable to the inverter. This is even easier if you are fitting an inverter charger to your van, which keeps the 230v circuits in the van live from battery/inverter when not on EHU, with auto changeover. Which method you use is down to what installation you choose. Personally, I believe that many owners install lithium because they want to run high power devices such as coffee makers, slow cookers, hair dryers and air fryers or similar. In these cases it is far more convenient to have the inverter connected to the vans 230v sockets so that they are live all the time, whether on EHU or inverter, with auto changeover. This is usually achieved by using an inverter charger such as the Victron Multiplus, but there are other methods, including some inexpensive ones using auto switches designed for generator backup - available from Amazon for less than 50 €£$. There is also the old fashioned way of manual switching, but with the price difference between manual and auto now so low, I can’t see the point in manual switching. I can provide details on this.

Solar charging

This is probably the easiest of all. Solar power is free from the sun, and is the only charge source that is available “off grid”, so is ideal for wild camping. Solar panels and MPPT charging are now so cheap, and powerful, that if you are fitting lithium batteries it makes sense to fit as much solar power as your roof will easily take. On most vans this will be between 200 and 400w. This means that on a summers day, you can reasonably expect to replace between 80 amp hours (200w panel) and 160 amp hours (400w panel) on a sunny summer day, based on 6 hours of sunshine. But in winter the figures can be as low as 20% of this because the sun is much lower and the days shorter in winter. This is no problem if you don’t use your van in winter, but for full timers it is a major factor in your off grid capability. Full timers who want to be off grid as much as possible need to fit as much solar as they can. This goes for any battery system, not just lithium. A common misconception is that a 200w solar panel is a constant - it is not! In December it is a 40w panel! And that is assuming that the sun shines in December.

Technically, modern solar MPPT controllers usually have a lithium profile, but you can still use those that do not. If the controller has user definable settings, just set everything to 14.2v. If this isn’t possible, then just leave it set to the lead acid profile, it won’t do any harm.

So those are the main points to consider about charging lithium.

Types of lithium battery

The next subject to discuss is "what type of lithium battery"? All lithium batteries for the leisure vehicle industry are lithium iron phosphate - known as lifepo4. These are the safest type.

Basically there are 2 choices - DIY or ready made. A lithium battery is very different from a lead acid battery - a lead acid battery is "dumb" - it is pure metal, plastic and chemical, and it has no electronics in it at all. A lithium battery is quite different - a lithium cell is 3.2v, so to make a 12v battery you need 4 of these cells in series, which totals 12.8v. Lithium cells must not be either overcharged, or undercharged, so to achieve this, and to offer maximum safety and long life, lithium batteries need a BMS - Battery Management System. This is an electronics board that is connected to each of the 4 cells, and monitors them constantly. It balances the cells, and it cuts them off if the voltage falls below, or exceeds a preset value.

A DIY battery is where you buy the 4 cells yourself, and the BMS, and connect them all together yourself. A readymade battery is where a battery company has mounted all the cells and BMS inside a box and done all the work for you. And because the leisure vehicle industry is so used to lead acid batteries, the box they use looks like a traditional battery.

It used to be that DIY lithium was cheaper than readymade, but nowadays this is not the case, especially for batteries of around 200ah or less. At the time of writing in Summer 2023, Renogy are selling a 100ah battery with Bluetooth for £420. But if you want a really big battery - say 600ah or more, it is usually cheaper to go the DIY route.

The differences between DIY and readymade are enough for an article on its own - but generally DIY is for enthusiasts, and readymade is better for non tech owners who just want to plug and play.

Finally .... do you really need it?

There is also one more big thing to think about - and that is - “do you really need it”??!!

There is nothing special about lithium - it is exactly the same volts and amps as any other battery, and is currently about 3 or 4 times the price. So you have to really identify the need.

The three main advantages of lithium are power density, long life and better information. Power density means you can get more power out of the same size - so a rough example would be if you only have space for 1 traditional 100ah leisure battery, and you don't want or can't relocate the battery, then you would get roughly double the power from the same space.

Long life is exactly as it sounds - they last longer. In regular use a standard leisure battery is only good for a few hundred cycles of charge and discharge which in average use means they need replacing every 2, 3 or 4 years. Lithium batts are good for thousands of cycles. The jury is still out because it's new technology but it is generally accepted that a decent lithium battery setup should last decades. So if you use your van a lot and intend to carry on doing so for years, then the financial deal alone can justify it.

But the third reason, better information, is for me, the best reason by far - better monitoring and information. The latest lithium batts come with bluetooth monitoring, and a phone app that displays accurate battery information. This tells you exactly how much power is left in the battery, how much charge you are getting (from all sources), and how much power you are using. Basically it is an accurate battery fuel gauge. After a few days of use you soon get a feel for your battery system, and can plan your activities accordingly. This is particularly useful for those who like to be off-grid as much as possible, or for those who may need to run devices that potentially use a lot of power, such as coffee machines, ebike chargers etc. You soon get to know exactly how much power these devices use, and how much charge you need to replace that power used - from solar etc. It is incredibly useful and gives you complete control, with no nasty surprises. With a standard lead acid battery - it is quite difficult (but not impossible) to get this sort of accurate information. Having used these Bluetooth lithium battery systems for over a year now, for me, it is by far the best reason to do the upgrade.

But none of that is to say that lead acid batteries are old hat or obsolete - they are not. A lead acid battery with a good solar system can easily provide enough power for normal summer holiday use. One of the best reasons to upgrade is when your existing system simply isn't giving you the power you need. The worst reason to upgrade is simply because it is the "latest thing".

You have to define your power needs, and then design the system around this

Lifepo4 charge discharge characteristics

A typical self build using 4 x 300ah lifepo4 cells, Bluetooth BMS board and busbars.

A typical BMS phone app, showing exactly what is being used, being received and how much is left.

TESTING CONTINUITY WITH THE MULTIMETER

One of the most useful tools in the box for sorting out wiring and cabling problems  is the continuity feature of your multimeter. On most meters it is marked with a small arrow. When selected, if you touch the probes together, the meter should make a sound - usually a beep - this means "short circuit".

Not all meters have this beep function. Most modern ones do, and if you are going to buy a meter, make sure yours does. On meters without the beep, then you have to use the "Ohm" setting, or "Diode" setting which will display zero on the meter display when you touch the probes together. 

So to test a connection, you touch one end of the wire with one probe, and the other with the other probe, and if you get a beep, then that proves there is "continuity" along that wire.

So if you have a bunch of wires at 2 ends, and no idea which is which, you use this feature to identify which is which. Attach one probe to one wire at one end, and then touch the other probe to each of the others until you get a beep.

But you have to remember that one end of the wire being tested is free - ie open circuit. You can't use this technique on connected wires, because there may be a path through another part of the circuit that will give you a false reading.

If the meter leads are too short, then you simply extend them using a long piece of wire, suitably connected - can be as crude as wrapping and taping. You check that you have a good connection by simply touching the probes together.

This technique is also useful for identifying grounds. DC current flows from pos to neg, with neg being chassis ground. If the ground neg wire or connection is not a solid path, then the circuit will not complete. So when testing and troubleshooting, you have to be sure that the neg has a good path to ground. The way to do this with a meter (set to continuity) is to attach one probe of the meter to the negative terminal of the battery - because that is 100% guaranteed to be the neg ... and then the other probe to the neg wire in question. Again, it is usually necessary to extend the meter probes. A favourite tool of the auto electrician is a 20 foot long meter extension wire with a crocodile clip that connects to the battery negative. Then neg grounds can be tested anywhere in the vehicle - especially rear light clusters - which are just about as far away from the battery as can be.

This is hopefully a simple explanation for motorhome owners - there are lots of Youtubes that explain multimeter continuity testing in more detail.

Inherited a van with an old LPG tank?

This article was written in reply to a new owner who had bought a 1988 B544 Hymer with an big underslung LPG tank, and wanted info. Most tanks are 40m 50 or 60L, so if you have a smaller tank - adjust the estimates accordingly - and remember - they are just estimates.

If the van is LHD then is likely an import, and the tank could have been fitted any time since. They were never a factory option - always fitted by dealers or gas companies - here or in Germany (usually).

Now what you have to understand about gas is that the equipment doesn't last forever, and at the very least should be checked over every 10 years or so. That is not to say there will be any danger - lots of people love to shout doom and gloom whenever the word gas is mentioned - I am not one of them. I know of plenty of original gas tank systems that are over 30 years old and still going strong. If you have reasonable common sense you can inspect the system visually and assess it yourself. If it fills with gas at the pump, and then after standing still on level ground with no wind, you can't detect the slightest whiff of gas from anywhere, and the appliances appear to work fine, then you have taken reasonable precautions and are most of the way there. But the general common sense attitude is that you should have any gas system checked over properly at least every 10 years. if you have children, it's more or less a duty!

The most important component is the regulator. Regs do have a use by date - and should be replaced every 10 years. Old regs can and do fail, and it is a regular question on this technical group. An LPG tank reg is the same as a bottle reg, but is usually bulkhead mounted, or mounted out of sight near the tank. Remember that old german vans pre 95 almost always have 50mb gas systems - not the 30/37mb that is the modern standard. Don't let any gas guy tell you otherwise.

if you do feel it prudent to have it checked over, then this group does have a recommended gas guy - Charlie Lister at Autogas 2000 Ltd up in Yorkshire. He will fit a new reg and check things over, and is a mine of info on all things gas. There are other firms dotted around the country, but Charlie knows Hymers and motorhomes in general and has been an invaluable source of advice over the years - so worth the trip.

About the gauge - the glass ones fitted on the tank are hard to read, but generally reliable. Study it carefully so that you understand it - you really have to read the dial to get to know what is empty and full position. There are usually accessory LED level gauges available nowadays, and these are convenient.

Your tank looks quite big - around 60L. The normal 11kg German bottles that fit the gas locker are 11kg, and there is 2kg in a litre. So 2 bottles is around 44L. The germans fitted them for 2 main reasons - 1. Long periods between refills, minimum hassle, max time on site or off grid. 2. Crossing European borders. There are several different bottle systems in different countries, which makes gas bottles an expensive inconvenience for long euro road trips, especially in winter.

So LPG tanks are the system of choice for long termers and road trippers. If you are planning multi country Euro trips, then you have a good asset. A new LPG tank system is around £1000 these days. I swear by mine - had it for 8 years now, been all over Europe and it has paid for itself twice over. All you need is a set of LPG pump adaptors and you are good for any country - and LPG is much cheaper than bottle gas. There are a few idiosyncrasies - ie no LPG in Morocco, and different tax rates in Italy, but I've always managed. LPG availability is also a factor. There has been much discussion in recent years about LPG slowly disappearing from UK forecourts, and this is true, mainly because of the electric car boom, but LPG as a fuel will be around for decades yet, and the only inconvenience I have found is that you have to plan your fill ups - there are non forecourt sources in most big towns and cities, and there are apps that tell you where they are. On the continent there is no problem.

Consumption wise, in summer, fridge and cooking, a 60L tank will last you for months - at least 3 or 4. In winter, when you have the heating on, then a tank will last you at least a full month using the heating for 12 hours a day. I have a 40L tank and in cold weather with the heating on 24/7 - ie non stop, I get 1 to 2 weeks. In summer it's every few months. It is heating that uses gas - fridge and cooking are low consumption.

At the other end of the scale - if you had it checked over and a professional condemns it - corrosion perhaps - then you can have it removed and revert to gas bottles for not much money - the plumbing will still be there and the installer will remove the old tank and install new fittings in the gas locker. This would probably be the best option if you don't want to shell out for a new tank - ie if you only plan to stay in the UK and not use the van very often, and only in summer. But I only add this for info - it is highly likely that your system will check out OK - most do.