OBC going a bit nuts

RX-78

Active member
Liverpool
Got into the car this morning to find OBC has reset every thing to naught - time shows --:--, average mpg 0, average mph 0, distance 0. The radio was still working as previously set. Thought not much of it, and put it down to a bit of blip.

Drove the car during the day and no prob.

Came home at night, switched the car off and noticed the lights in the indicators etc didn't go off. The head light were switched off ok. Strange, I thought but decided to lock the car and see if the indicator light goes off. It didn't. After a few minutes, re-started the car, turned it off and the indicator finally switched off.

Not sure whats happening here. Anyone has any idea :? ??
 
Do the lights on the OBC dim a bit now and then? Similar happened to me and it was a battery that needed charging.
 
They've not dimmed/flashed. The electricals seems to run fine when the car is turned on - radio fine, BT connects fine, OBC can joggle between mpg/mph,distance etc. Wipers, signals, headlights, aircon all working fine as well.

Its AUC so BMW's only checked the car 5 months ago and also had oil service 2 month ago!
 
I have had a similar recurring problem with my Coupe which I put down to a lowish battery. Essentially when doing a lot of short trips, on the colder mornings when starting the car the car started perfectly however for a couple of seconds the dash lost all power completely, lights would go off, trip resets, OBC resets, rev counter falls to zero. I think it's a case of the battery not being able to support all the power being requested and therefore power is withdrawn from various systems. As I currently use the car for a longish commute (80miles a day) I haven't seen this for some time.

Also, interestingly every now and again I have experienced the problem referred to by flimper - i.e. dimming of the OBC....

Anyway I think this all points towards a battery which has seen the best of its life....
 
Thanks guys. I suppose knackered battery makes sense with re-setting of OBC as I do lots of cold morning short runs. Not sure if it explains the indicators not switching off when the car is turned off and locked though.

Will add to list of things to be fixed before end of warrenty and will let you guys know!
 
AlanJ said:
flimper said:
Do the lights on the OBC dim a bit now and then? Similar happened to me and it was a battery that needed charging.

......or replacing.

Looks like you are spot on :( Charged the battery for a couple of hours the other day, then did a long run today and the OBC lights went out completely for a time. New battery required :evil: Any advice on what to get or is it just an expensive trip to the dealer?

Something I noticed while charging which seemed odd was that one light was on and one wasn't. A problem or normal?
 
I'd go to Halfords and buy one of their Calcium batteries. You get a 4 year warranty (Vs Dealer 1 year) and it will cost way less than the dealers at around £100.

Search Halfords under car maintenance, batteries and you can enter your reg for a list of types and prices
 
What is the expected life of a battery? Should the battery in a regular-used Zed last longer?
 
If put on a trickle charger years. I killed the battery on my previous Z in two years due to excessive draining.
 
pvr said:
If put on a trickle charger years. I killed the battery on my previous Z in two years due to excessive draining.

think flimper bought one of these then realised he had nowhere to plug it in.
 
I bought one and have been using it since the cold snap but I think the damage done is irreversible, I don't use the car as much as I'd like and the first owner did 5.5k miles in 2.5 yrs. Not a shock really that the battery has given up the ghost.
 
On a standard battery it's cycling ie, discharging/draining then charging, that kills batteries due to internal changes on on the plates. Using heavy winches on Jeeps we reckon 2 years tops so have to use special deep cylce batteries (Yellow Top, etc.).

As pvr notes kept well charged ie with regular use and a good charging system on the car, or an appropriate charge/maintainer then years. My original X5 battery was in use for 6 years and about 70k mikes. I kept it topped up in the garage and fitted it to my Jeep as a second battery. It was yesterday still capable of spinning a 4 litre engine happily after 8 years of life :)
 
What about laptop batteries? If my work laptop is always connected to the main, should I take out the battery from the laptop? Or will the laptop stops charging the battery once it is fully charged?
 
ksher said:
What about laptop batteries? If my work laptop is always connected to the main, should I take out the battery from the laptop? Or will the laptop stops charging the battery once it is fully charged?

best to use on battery where possible and then charge and remoave mains when charged again.
 
srhutch said:
ksher said:
What about laptop batteries? If my work laptop is always connected to the main, should I take out the battery from the laptop? Or will the laptop stops charging the battery once it is fully charged?

best to use on battery where possible and then charge and remoave mains when charged again.


Why use on battery then recharge?

Of course it's impossible to speak of every single make of laptop but in general they use Li-ion batteries and charge until full or close to full, then shut off the charge. It's the cycling to empty and then recharging that kills them over time.

Quote - Wikepedia
A disadvantage of lithium-ion cells is their poor cycle life: upon every charge or recharge, deposits form inside the electrolyte that inhibit lithium ion transport. Over time, the capacity of the cell diminishes. The increase in internal resistance affects the cell's ability to deliver current. This problem is more pronounced in high-current applications. The increasing capacity hit means that a full charge in an older battery will not last as long as one in a new battery (although the charging time required decreases proportionally, as well).
 
Just been down to Halfords, old battery was reading 11.96v and 70%, so decided to get it replaced with the £105 Calcium jobby. Thanks for the advice :thumbsup: Will look after this one properly!

Edit: Unfortuantely it reset the codes, so I no longer have the windows auto up or the auto lock feature :(
 
flimper said:
Just been down to Halfords, old battery was reading 11.96v and 70%, so decided to get it replaced with the £105 Calcium jobby. Thanks for the advice :thumbsup: Will look after this one properly!

Edit: Unfortuantely it reset the codes, so I no longer have the windows auto up or the auto lock feature :(

Glad to be able to help.

Changing batteries should not have any effect on any programming of car or keys. all it shoudl do is zero out OBC features - mileage, MPG, clock etc.

I presume this was done by an Indy and must therfore be co-incidental that it does not work, or done in a more volatile manner??
 
Or you can re-initialise the sequence of the windows again (was it close the windows fully and keep pressing the button for 8 seconds or so, can't remember ... must use search).
 
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