Locked out of relay due to dead battery - can't charge. Help needed

[ml11ML]

Interesting. Then my u1000 code might have been caused by a slightly corrupted bsi that half a year later has somehow uncorrupted itself as it was a "no canbus to the bsi" type code after all. As everything on the car still worked that means the bsi just thought there was no canbus link while there actually was...

I haven't lost any settings though and the error code first appeared about a day after I removed the battery so who knows really...

[dilby]

Hi all - I've finally managed to sort it and thought I'd post my findings. My hesitancy regarding disconnecting and generally messing about too much with the battery was because I'd read several people who'd had to take their vans to a dealer to sort out new immobiliser resets and issues with the stereo (and start/stop system if you have it). I don't actually have an immobiliser code as the dealer didn't give that to me (I need to chase that up) and as I'm not really very mechanically minded (am trying to learn) I was just a little apprehensive.

The battery was just not showing on the plug-in charger, so I figured I'd have to remove it in any case, as it's either dead or needs charging from another vehicle. So I removed it; I did manage to find this process outlined in the manual, but for me as the battery was already dead I just disconnected it all (negative first). Weirdly the manual says the battery is both under the bonnet and also under the cab floor, and there are also several other contradictions. Once disconnected I connected it with jumpers to my car and let that run for a while. I then found that the plug in charger read the battery and said it was on 1 bar, so it must have been showing an error as it was entirely drained and unreadable. I then left it to charge for a few days, reconnected it and viola.

In terms of the drain, I've done some reading and it seems the main culprit is the immobiliser. The manual says if not driving the van for 1 week then to disconnect the negative terminal (which is a spring clip) to prevent the drain. As that system would be hard to disable by definition, for now I'll keep a screwdriver handy in the glovebox to remove the floor lid and disconnect this battery in that event. But long term I'm going to look at several options that exist for enabling a trickle charge, some as mentioned above. But baby steps for now. I am curious though what larger campervan manufacters do that use these vehicles as a base, as they're often left unused for weeks on end.

Thanks again for everyone's help and support.

[Hell Razor5543]

You may not need an immobiliser code. Normally the immobiliser system has a chip in the key (little glass capsule, bit larger than a grain of rice) which is read by an inductance coil around the ignition barrel. When you turn the key the coil is energised, the chip is read, and if it matches the code in the system the engine is allowed to start. The radio should also work, as it will have been coded to the VIN (so, provided it remains in the vehicle, it won't 'lock'). However, you might need the security card (if you don't have it) which will allow certain tasks to work on the vehicle (such as coding in a new key). When a vehicle is delivered to its owner there will be two cards (the size of a credit card), with a scratch panel. This is hiding a four digit code, so when a 'security' related procedure is started (such as the new key) the system will request the code in order to proceed.

Sometimes there are different configurations for vehicles, so it could be that the contradictions you have encountered would be correct for a Citroen Relay with a different spec level than yours.

[white exec]

Thanks for posting the update - it really does help to understand what's been happening.

With a battery in good condition, it really is a nonsense for it to be needed to be disconnected if the vehicle is not to be used for one week! That sort of precaution could conceivably be good advice if no use for 4-6 weeks+, but not one week.

There's always a residual drain from the battery, but it should be in the region of 30mA (0.030amp) or so, or even less. At 100mA, you're in serious non-starting territory, if not driven for a good few days. You can check the residual (quiescent) drain by disconnecting one of the battery terminals, and remaking the connection with a test meter set first to 10A (as a precaution), then, if the reading is nice and low, switch to the 200mA range. Ensure that everything is switched off when you do the test, including doors etc closed. Let things stabilise for 10mins or so, while bits of electronics reboot/restart, before taking the reading.

To keep a vehicle batttery in good condition, especially on a vehicle that gets intermittent use, if you're in spitting distance of a power point, then just get a good intelligent charger. One of the best-rated on market are the CTEK ones, and the CTEK MXS 3.8 is the best to go for. It will provide 3.8A of charge when needed, but can just be left connected indefinitely. I've used one of these for years now, and have recently bought a smaller one ( their XS 0.8) for smaller battery use. (The 0.8 is not powerful enough to charge a normal car battery from flat, where the 3.8 will.)

Some intelligent chargers do not like looking at dead-flat batteries, and this is where an old-school charger (transformer+rectifier+ammeter+fuse) can come in handy. They can also whack out 10-12A, which can be useful.

The CTEK isn't the cheapest, but it's probably the best. Lots of cheap copies around, so worth buying the real thing, eg from Amazon.
https://www.ctek.com/uk/education/car-battery-chargers