Background:

When as complete newcomers to caravanning we bought our 2003 Triton in May 2011 from AL in Poole, we were blissfully unaware of the horror lurking under the seat next to the wardrobe just lying in wait to bite us when least expected. Like most owners, I suspect, we had never heard of the dreaded “BIP unit” and were completely unaware of what it does – or in our case what it was supposed to do.



The “Boîtier d’interconnexions et de protections” (BIP for short) is the name that the French manufacturers Scheiber gave to the electrical junction box fitted to many Eriba vans of a certain age. Its function is to distribute the 230V AC mains supply from the electrical hook up (EHU) to the wall sockets and fridge and to provide, via a transformer, fused 12V DC supplies to the lights, water pump, heater fan etc. The BIP also incorporates a battery charging circuit to keep the battery fully charged when on EHU. Well, that’s the theory.

Unfortunately when we took our van for its first trip to the South of France in September 2011, we were unaware that the battery charging circuit was defective only finding this out when the lights started to flicker and grow dim one night on EHU near Avignon. On the advice of Wirral-based electronics expert John England, I bought a multimeter from a local supermarket and carried out some voltage readings that I emailed to him for analysis. John quickly confirmed that the BIP was not charging the battery so, as I needed power for the motor mover, he suggested that I buy a car battery charger and run it from the unaffected 230V supply. This worked fine as a temporary stopgap for the rest of the holiday.

On returning to the UK, as we were well out of AL’s three month warranty period, I sent the BIP to John for repair. He found that a transistor and a couple of resistors in the circuit that controlled the charging voltage had failed, due probably to overheating, and replaced them.

After the repairs the BIP worked perfectly again and the panel voltmeter that I’d fitted in the side of the wardrobe to monitor what was going on under the seat showed it to be maintaining a steady 13.7V to the battery, exactly in accordance with the design specification of 13.7+/- 0.1V.

Job done! Or so I thought as a little more than two years later, the BIP failed again. Oh, bugger!

April 2014

It was when I was cleaning the van after a week away in March that I noticed the indicated voltage had dropped to 13.1V indicating that the BIP was no longer providing the 13.7V maintenance charge needed to keep the battery fully topped-up.

This time, Eribafolk’s ‘JohnE’ (who is now a self-employed mobile caravan service engineer) suggested that what he referred to as the ‘antiquated and unreliable charging circuit’ in the BIP needed drastic modification to bring it up-to-date and make it completely reliable. John’s recommendation was that he remove the BIP’s existing charging circuitry completely and replace it with a separately mounted, three-stage charger incorporating the latest charging technology. The BIP unit would be retained to provide fused mains and 12V power throughout the caravan and to provide power to the new charger.



Luckily when I had removed the BIP in October 2011, I’d labelled each connection and thankfully I’d left the tags in place when I reinstalled the repaired unit. Taking the BIP out is not difficult but I wouldn’t like to have to refit one without knowing where to connect the rat’s nest of wires left behind, as can be seen in the picture.



There are two circular, cable-entry holes in the rear of the BIP unit and its alloy mounting plate. I found it useful to put cable ties around each bunch of wires prior to removing them to help make replacement simpler and safer. Photographs taken at each stage will also be of assistance. Whatever you do, don't trust to memory.

Once the BIP was out again I cut the wires and removed the 12V transformer. This would no longer be needed when the new charger was installed and with it removed, the unit was much lighter and therefore considerably cheaper to send through the post.



Once he had examined the BIP on the bench, John and I discussed my options. We decided that for complete future peace of mind while touring, I’d fit an Amperor 18A charger that incorporates all the latest technology and has its own ‘intelligent’ cooling fan that operates only when necessary to protect the electronics from overheating. Amperor+Associates Ltd.

I ordered the charger through Amperor’s website for £74 delivered to my address and John provided the necessary connections from the BIP for me to cut to length and fit the appropriate crimp-on female terminals. The charger comes with a one metre long mains lead that plugs into a socket in the charger and has tinned ends ready to take crimped female connectors.



John also suggested that while he had the BIP it would be a good idea to replace the on/off switches on the front panel with modern RCD trip switches. Prior to this revelation I’d always assumed that the switches were RCDs!

Not having had much success in the past with crimped connections, I was surprised when John told me that they are far superior to soldered terminals, provided a suitable crimping tool is used to attach the terminals to the wires. On his advice I bought a ratchet crimping tool (£17 delivered through eBay) that allows you to apply much more pressure than the more common, simple crimping pliers that are designed for a different type of fitting. The new tool is designed for use with red, blue and yellow pre-insulated terminals and produces perfect results every time. I also had to replace a few poorly attached terminals that came off the BIP wiring when I removed the unit.



The next question was where to locate the new charger? It needs space around it for the free circulation of cooling air and to achieve this I had to relocate a couple of floor-mounted fuse holders situated in front of the Schaudt booster that charges the battery via the car’s electrical system while the caravan is being towed. I couldn’t work out how to remove these fuses that seemed to be screwed to the floor with no visible access to the screws. In the end I emailed John for advice and felt a right chump when he told me that they are simply a push fit into holes drilled in the caravan floor. All it takes to remove them is a flat bladed screwdriver pushed under the base of the fitting and twisted. Relocating the fuses was simply a matter of drilling two more holes in more convenient places and pushing the pegs in. Easy – when you know how.



While fiddling with the fuses I noticed that the Schaudt booster had only ever been fixed to the floor by a single screw at the front allowing the unit to move about when the caravan was being towed. An extra screw at the rear cured this. I also found that the 2 amp fuse in the switching circuit had blown (I have no idea when) so the booster also could not have been working while towing.

May, 2014

With the fuses moved/replaced and the new charger mounted to the floor, fitting and reconnecting the now eviscerated BIP was straightforward and simply a matter of fitting wires to the appropriate terminals served by the correct fuses, being very careful of course not to confuse mains and 12V connections.



One other modification that John had carried out for me was to use the redundant switch on the BIP (that originally allowed the 12V circuits to be run from the car’s battery when car and van were still connected and which most people never use) to allow the washroom and sink taps to be left open while the EHU is connected and the heating circulation fan to be isolated. (Second switch from the left - the blue thing next to it is the fridge relay.)



After checking all the connections once again, it was time to switch on the power and test that everything was working correctly so, with some trepidation and fingers crossed, I connected the battery and checked that all the 12V equipment was working correctly. The heater circulation fan gave me a moment's concern until I remembered to put the switch on the BIP 'on'.

Once I was happy with the 12V supply I connected the EHU, switched on the BIP then the charger and finally the power to the Trumatic heater. Nothing went bang. This is always a good sign.

With all circuits working correctly, the acid test was to operate some 12V fittings to discharge the battery and then see what happened to the voltmeter. With the old BIP, the voltage used to flicker about all over the place before settling down to 13.7V but the new system maintained a rock-steady 13.8V. As I progressively switched on the non-led lights, I saw the voltmeter flick to 14.5V and as I switched them off it returned to 13.8V.



The next test was to see what happened when I connected the van to the car’s electrics so I manoeuvred the van to the car using the Reich mover and hooked up to the 13-pin socket. When I started the engine the green light on the Schaudt booster came on and the voltmeter read 14.3V as per specification. I also checked that the red 12V light on the fridge came on. This shows that 12V is available to the fridge heating element but not that it is necessarily working.

I then put the van back into its parking space with the mover and reconnected the EHU. Using the mover had partially drained the battery and the voltmeter now read 14.5V indicating that the new charger had gone into the second stage of its charging cycle before returning to its normal 13.8V after about five minutes.

The only "problem" that I found was that the awning light now operates irrespective of whether or not the EHU is connected. I thought this was a small price to pay and resigned myself to it but when John rang to check on my progress, he explained that the original BIP had its own 12V transformer and when its circuitry detected that mains current was connected it then switched a relay to allow the awning light to operate. As the 12V transformer has now been removed, John has wired the system to operate a relay on the printed circuit board when the caravan is attached to the car. This relay now inhibits the awning light from operating when towing thereby preventing me from breaking the law. Clever, eh?

So that’s it. The BIP as I knew it is no more and our 11 year-old Triton now has what should prove to be a far more reliable, up-to-date electrical system complete with residual current devices and a three-stage battery charger that can be left permanently attached to the EHU throughout the winter months. What a relief!

Finally, I would stress that I have no connection with John England other than as a very satisfied customer. If you wish to discuss any caravan problems with John or arrange to have servicing or repairs carried out, he can be contacted via his website Neston Caravan Services.