l320 battery

Hi;
New problem!

I have a battery/charging issue that is causing a flat battery if I leave the car for a couple of days. The battery is 90 and 800 on the amps (whatever those numbers mean!) and when tested it was 68% which the guy thought was ok. But looking around these numbers seem a little low. Any thoughts???

68% is certainly on the low side for the electronics on these vehicles as the voltage may drop too much when starting. What voltage do you have on the battery with the engine running immediately after starting?

Good question. Owing to a lack of voltage tester (don't judge me!) I had to take it to a battery place and that's what he came up with with his tester.

I was wondering also if there was anything that could drain the battery if it was sitting there locked doing not much. Wondered if there were any known issues?

Guernseyal said:

I was wondering also if there was anything that could drain the battery if it was sitting there locked doing not much. Wondered if there were any known issues?

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Buy yourself a cheap digital voltmeter £15 or less.
A tired battery can self discharge without any help from the car
The battery voltage should be 12.6 volts or more 24 hours after you switch the engine off.
There may be an electrical drain problem but checking that the alternator is charging and that the battery is holding a charge are really the first steps.

L320 battery needs to be disconnected before doing CCA check, otherwise the car electronics cause false readings !!

Well I hope the people doing the check knew that. Hopefully as all they do is batteries and electrics that should have been accounted for. If not I bought a battery for nothing - doh!

Main earth point under the front right wing behind the wheel liner
For the replacement battery fit a Hankook mf31-1000

They stuck in a Yuasa YBX5019 that was a mere £172. If it had been a stop start model RR then it would have been nearer £250!

We're the earth and charging circuits checked do you know..
You could be back later with the same problem

Mark Piercy said:

Main earth point under the front right wing behind the wheel liner
For the replacement battery fit a Hankook mf31-1000

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For an L320?

Datatek said:

For an L320?

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Yip, did one last year. Made a massive difference to the car. The new some had fitted worked along with plenty of other things like the radio.
Corroded to buggery

Mark Piercy said:

Yip, did one last year. Made a massive difference to the car. The new some had fitted worked along with plenty of other things like the radio.
Corroded to buggery

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I shall remember that

Update if you're interested...
The new battery has solved the problem, so I'm calling that a win. Interestingly there was a HDC fault reported most days and that has also disappeared. Odd but could have been down to low voltage.

Now awaiting the next round of fun when a new problem arises!

Guernseyal said:

Update if you're interested...
The new battery has solved the problem, so I'm calling that a win. Interestingly there was a HDC fault reported most days and that has also disappeared. Odd but could have been down to low voltage.

Now awaiting the next round of fun when a new problem arises!

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They are very sensitive to low battery voltage. good that the battery has fixed the problem and thanks for the update

The reason being is that the ecus on the car can run from 2v upto 5v.
On a weak battery when the starter is engaged it robs the ecus of their current and puts them Into an uncertain mode this is where the codes and errors come in. Usually the srs/airbag and abs systems. Hdc, esp and so on.

Mark Piercy said:

The reason being is that the ecus on the car can run from 2v upto 5v.
On a weak battery when the starter is engaged it robs the ecus of their current and puts them Into an uncertain mode this is where the codes and errors come in. Usually the srs/airbag and abs systems. Hdc, esp and so on.

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You sure about that 2 volt figure?

It's depends on the system and it's purpose.

Mark Piercy said:

It's depends on the system and it's purpose.

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Hmmm something to learn here, I don't know of any electronic system that uses less then 3.3 volts and that is within the ECU so more info please.

Lambda sensors my good man their ranges rise and fall.
Not supply voltage but inner working voltages.