Going to disconnect the battery of an FL

PaulT said:

To avoid the problems that can come with disconnecting the battery on an FL, i.e. locking and other problems then buying one of these may stop the problems by keeping the modules powered

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Click to expand...

I would still ensure that you do your best to ensure all modules are shut down to the best of your abilities as it will probably struggle to maintain the voltage/current required if the car has just been opened/awakened. A second battery or even car is also another easy option to do so with some jump leads.

Is there a connection point under the bonnet somewhere you can clip onto, as imagine it will be nigh on impossible to connect onto the battery clamps in the boot at the same time as disconnecting the existing battery, not to mention the danger of shorting the positive onto the bodywork by accident.

All well and good still but most people need to disconnect the battery for reasons other than simply to change it. Usually to change a module or remove a seat (airbags etc) in which case you need the system powered down regardless.

I wouldn’t fancy putting any sort of serious current through the ODB port.

You be better with a cheap 30A 12v power supply off Amazon.

Surom 12v 30a Dc Universal Regulated Switching Power Supply 360w for CCTV, Radio, Computer Project https://amzn.eu/d/6ckrAVz

Statler said:

I wouldn’t fancy putting any sort of serious current through the ODB port.

You be better with a cheap 30A 12v power supply off Amazon.

Surom 12v 30a Dc Universal Regulated Switching Power Supply 360w for CCTV, Radio, Computer Project https://amzn.eu/d/6ckrAVz

Click to expand...

I only just realised it was through the OBD port.

Nor would I want to use such a device. I'm not even sure if the OBD port itself is powered down and switched, so it may not work after the car has shut down fully.

Like I say, a better way would be to connect some jump leads from a battery, or another car.

Man, you are right
OP please have a look at the small OBD contacts and have in mind the car will consume about 20A..30A if all modules are awake. What a heart warming situation for these OBD contacts....might melt like your wife in your charming arms
I wouldn't find out if it really works. If the power management will reduce the power consumption to realistic value for the OBD port. Might work, that only the communication and EEPROMs of all modules will be kept alive.

Cheers
Dirk

Check the wiring diagram, I'm hoping the ODB 12v rail is fused. Which will immediately blow if this was connected and the main battery disconnected, likely causing all manor of documented issues. Either use the jump terminal posts, if fitted, under the bonnet, which are designed for high (but not starting) current, else insulated heavy duty crocodile clips on the battery clamps and lots of insulating material in the boot.

Looks like a good way to brick your car and only just over £7. But is saves fuel as well with it's flashing LED, so not all bad!