Changing the battery; what's going on ? - Clanger
I fitted the C3 with a new battery this morning. Very pleased with the simple plastic catch that locates the battery.

Hoping to save the radio stations and the date and time, I plugged in my home-made power supply which is a Nokia phone charger giving 11.7 volts and a fused cigarette lighter plug. This has worked OK in the past.

When I disconnected the battery a regular clonking sound was heard causing the interior light to dim in time with the noise as though a relay was trying to do something. I didn't like the noise and disconnected the power supply. Losing the volatile data was no big deal but I'm curious.

What might have been going on ?

Changing the battery; what's going on ? - Dr Rubber
Does the C3 have "economy mode" like othe Citroens? Is so the supply to the cigarette lighter is switched off at the cars CPU so it might not like being powered in reverse.
Just a guess.
Joe
Changing the battery; what's going on ? - Altea Ego
The static current draw on a modern car is more than the paltry 500milliamps your nokia charger can push out. Hence the charger was shutting down due to overcurrent.

Anyway, with a modern can bus car, the chances of your device managing to get power to the right places in reverse is pretty remote.
Changing the battery; what's going on ? - M.M
H. I've noticed the C3 electrics/electronics are always "thinking" rather than being simply on/off as in the old days. I bet your 11.7v dropped down under load and made the car's system stutter as others have thought..

When you say you've used it before do you mean on the C3 or another old generation car?

The C3 does have economy mode... well our 2006 model does.

Edited by M.M on 23/01/2010 at 20:24

Changing the battery; what's going on ? - Clanger
Good thinking.

Yes our C3 does have an economy mode.

If the static current draw is more than say 500 mA why isn't the battery always flat? It's only a 50 AH battery after all. At 1000 mA that's only 2 days reserve. At 500 mA 4 days, or is my maths and understanding of power drain up the creek ?

Last used my device on the Synergie, a previous generation away. It's probably time to bin my brainchild!

Changing the battery; what's going on ? - Altea Ego
If you had the door open, the car was alive. Modern cars tend to wake up into a pre start mode when you open the door, and then go to a low current sleep mode about 10 minutes after you shut and lock the door.
Changing the battery; what's going on ? - Clanger
Right. The car was "alive". The driver's door wasn't fully shut and the interior light was on. OK I'm following this. Thanks all for thinking this through for me.
Changing the battery; what's going on ? - M.M
I wonder if the action of changing the battery with the "saver" in the cigar lighter had the effect of waking up the electrics which in turn demanded a far greater current draw than when everything is properly idle?

My uncle grumbles about the economy mode as it keeps turning the radio off when he's parked and listening to something.
Changing the battery; what's going on ? - RichardW
Google BSI and voltage spikes, and be glad that it is not in the dealer for £500 worth of repairs.... Changing the battery on modern cars is not to be taken lightly! I sat in the back of our Picasso for 5 minutes at -8 recently waiting for it to go to sleep before I disconnected the battery.
Changing the battery; what's going on ? - gordonbennet
I can't be the only one who tries to leave another battery/jump pack connected whilst doing a battery swap, sods law dictates the time i don't will be the one time something expensive goes pop.
Changing the battery; what's going on ? - M.M
Thanks for the reminder on this Richard. I've found the best procedure mentioned on Google for Citroen/Peugeot and pasted it in here...

PROCEDURE FOR BATTERY DIS-CONNECTION (The 3 Minute Rule)
Whenever a vehicle battery has to be disconnected, switch off all equipment,
interior lights etc, close the doors leaving the driver?s window open.
Switch off the ignition and remove the key and any DIAG equipment.

Wait a full 3 minutes before disconnecting the battery.

The BSi must be allowed to go to SLEEP i.e. into "power save mode". Do not
operate any equipment on the vehicle during this time. Remember, even
opening the bonnet will wake the BSi on a vehicle fitted with alarm.

If the battery is under the bonnet, open the bonnet first and leave it up.

ALWAYS disconnect any DIAG equipment and do not operate any plips from
other vehicles during the 3 minute waiting period.


PROCEDURE FOR BATTERY RECONNECTION
Unless otherwise instructed by Product Service, you must always
carry out the following procedure, often referred to as a "soft re-boot", to
minimise the possibility of the BSi corrupting its own software when
reconnecting the vehicles battery supply.
Ensure the procedure for battery disconnection has been adhered to and
importantly all BSi functions were switched off with the driver?s window left
down.
1 Close all doors
2 Remove ignition key if left in ignition
3 Reconnect battery. DO NOT open any doors
4 Wait 10 seconds
5 Switch on headlights through the driver?s window (you will hear a "bong")
6 Switch on ignition then start the vehicle and check system functions

NOTE: Upon reconnection, if any vehicle function controlled by the Bsi, i.e .
interior light, is switched on the internal operation of the BSi has the potential
to spike or corrupt its configuration and software program.

Changing the battery; what's going on ? - Clanger
Thank you M.M and all who replied. Mrs H used the car for work yesterday and has taken it again today with no apparent ill effects. Lucky, I guess.

Now, broadening the discussion, what do I do if the C8 battery needs replacing ?
The battery lives under the driver's floor area and access is through the open driver's door.

Find the interior lights fuse and pull it before letting the car sleep ?
Changing the battery; what's going on ? - jc2
Read the C8 handbook?
Changing the battery; what's going on ? - Clanger
Read the C8 handbook?


How politely you express the rather coarse RTFM ;-)

Done it. p.117
"Changing the battery
Replace with a battery of the same type."

Now a whole heap of use in the context of corrupting software and large expenditure at the dealers.
Changing the battery; what's going on ? - gordonbennet
Now broadening the discussion what do I do if the C8 battery needs replacing ?
The battery lives under the driver's floor area and access is through the open driver's
door.


If there are jump start connection points under the bonnet it's simplicity itself, just connect a jump pack or other car to the connectors and change away...make sure the live battery lead doesn't touch earth during the change mind...a Marigold is very handy for wrapping the connector.
Changing the battery; what's going on ? - Clanger
...a Marigold is very handy for wrapping
the connector.


These Marigolds get everywhere!

www.honestjohn.co.uk/forum/post/index.htm?v=e&t=18...2
Changing the battery; what's going on ? - gordonbennet
These Marigolds get everywhere!


Yes a Marigold is for life not just Christmas.;)
Changing the battery; what's going on ? - Doc
This guide is useful:
How to change a car battery
without losing your radio code



tinyurl.com/yagm8jl
Changing the battery; what's going on ? - RichardW
Similar to the Piacsso I guess. Expose the battery, and prepare the tools required to disconnect the battery. Sit in the car doors closed for the 3 minutes, then disconnect the battery, Now you can open the door and change the battery over, get back in, and with the door shut, reconnect, and observe the reconnection procedure.

At least on the Picasso the battery is under the passenger seat, so you can sit in the back reading the paper whilst the BSI goes to sleep!
Changing the battery; what's going on ? - Clanger
... with the door shut reconnect and observe the reconnection procedure.


The door pockets overhang the battery and I'm not sure I could reconnect.

You're not buying the 'pull the interior light fuse' story then ?
Changing the battery; what's going on ? - TheOilBurner
Thanks M.M. I can speak from bitter experience with a C5, that if that procedure isn't followed, you can cause all kinds of weird faults with the car...
Changing the battery; what's going on ? - Pugugly
Going to move this to Technical soon - too useful advice not to be found under a search in that area in the future.
Changing the battery; what's going on ? - SteveLee
Don't forget to open/close all windows and leccy sunroof (if fitted) to reteach the controllers the various positions. Failure to do this might mean the car decides to open your windows at some random point in time!
BSI spiking after connecting tyre pump immediately - Banky

Thanks for all the contributors. I seem to have found out the problem with my car now. The car never start after trying to connect tyre pump on connecting the battery. The interior light dims. Radio displays show eco-mod. I guess my ECu has corrupted. Any idea where this could be repairedfor less.

BSI spiking after connecting tyre pump immediately - Banky

Sorry not the ECu but the BSI unit.