New Battery -> Remember to Reset the Low Battery Counter

[Tannaton]

It also gives the mechanic a sense of whether the customers' account is correct....

[RS3100]

Originally Posted by SwissXC90

Exactly. They are for diagnostic purposes.
And they can only provide useful information if the counters are reset when a new battery is fitted, not afterwards.

Resetting when you have a problem does not help. Because then you have no historical data.

So is this a BMS reset or something else that should be done in addition?

[SwissXC90]

Originally Posted by RS3100

So is this a BMS reset or something else that should be done in addition?

The XC90 has no BMS (Battery Management System)

The 2 x low voltage counters are just that: low voltage counters
When you reset the counter, you reset them to 0.

Every time a low voltage condition is detected, the counter increments by 1.

[Zebster]

It's rather meaningless without a corresponding explanation of the circumstances associated with each particular incident; what can possibly be inferred by, say, the 69 incidences that your own car had recorded?

Hence why I suggested it would be more meaningful to reset the counter(s) at the onset of a problem and then conduct a proper trial where each low voltage incident might be attributed to a particular circumstance.

The lack of a BMS seems a backward step?

[SwissXC90]

Originally Posted by Zebster

It's rather meaningless without a corresponding explanation of the circumstances associated with each particular incident; what can possibly be inferred by, say, the 69 incidences that your own car had recorded?

Hence why I suggested it would be more meaningful to reset the counter(s) at the onset of a problem and then conduct a proper trial where each low voltage incident might be attributed to a particular circumstance.

The lack of a BMS seems a backward step?

Remember, we are talking about a car designed about 20 years ago.
That's the way things were back then. Volvo never put a BMS into the XC90 of those days.

Historical data always assists in the analysis of a batteries health.
Having a low voltage counter showing 5 low voltage incidents since the battery was installed, or one showing 55 since the battery was installed, both are very meaningful and both tell a story.

When I replaced my battery, it showed 67 low voltage incidents.

Anyway, it's pointless to say "wouldn't it have been better if Volvo had added a BMS / online diagnostics / real time data tracking / apps on your phone that monitor every parameter of the car / crowd-funded open source platform development" because they did not. And you cannot change that.

[Zebster]

Originally Posted by SwissXC90

Remember, we are talking about a car designed about 20 years ago.
That's the way things were back then. Volvo never put a BMS into the XC90 of those days...

...Anyway, it's pointless to say "wouldn't it have been better if Volvo had added a BMS / online diagnostics / real time data tracking / apps on your phone that monitor every parameter of the car / crowd-funded open source platform development" because they did not. And you cannot change that.

Quite right! I apologise for somehow wrongly getting it into my head that you had a modern SPA model.

Originally Posted by SwissXC90

Historical data always assists in the analysis of a batteries health.
Having a low voltage counter showing 5 low voltage incidents since the battery was installed, or one showing 55 since the battery was installed, both are very meaningful and both tell a story...

So what stories/conclusion(s) must now be drawn from these 5 counts since the battery was installed... Was it discharged when installed? Or is it defective? Or is your alternator weak? Or is it really cold where you live? Or something else? Or just ignore it?

[Harley Dave]

Originally Posted by SwissXC90

"My count on the old battery was at 69, it is now at 0 "

[/B]

I believe Swiss was using the number 5 as an example rather than actual data from his car.

Cheers

Dave

[Zebster]

Originally Posted by Harley Dave

I believe Swiss was using the number 5 as an example rather than actual data from his car.

Cheers

Dave

Ok, but if/when it does read 5 (or anything other than 0), then my post still stands... What action would then be appropriate?

[SwissXC90]

Originally Posted by Zebster

Ok, but if/when it does read 5 (or anything other than 0), then my post still stands... What action would then be appropriate?

You make an assessment of what to do next

If the customer complains about hard starting, and the battery counter has a high low-voltage-count value, then you know where to look

If the customer complains about hard starting, and the battery counter has a very low-voltage-count value, then you know the battery is likely fine

[Harley Dave]

If, after a longish drive, (more than one hour at highway speed) I got a low battery count within (say) 12 hours, I'd be suspecting a charging problem.

If, after standing for 24+ hours, I got a low battery count, I'd be looking at what the drain was with ignition off.

But I don't have to do this because, under Swiss's lead/guidance, I have the CEKA real time battery monitor installed and I can check the "battery status" over the preceding period showing the usual voltage drop overnight and rise as the day warms up and also showing clearly drops for starts/slow running as well as use of wipers/windows/sun roof etc while stationary.

I have a "home brew" solar panel connected via the OBD2 socket (with an "always live" charging socket up front)

As far as I'm aware I'm on the original battery (late 2011 reg on 75000 miles) and it is occasionally "slow" to turn the engine first thing in the morning - but has not yet failed.

Cheers

Dave