Battery Condition?

PhilT · Post by **PhilT** » Mon Nov 29, 2010 9:42 am

Hey everyone

Is there any way to check the condition of the battery - like a voltage level or something, and if so what should it read?

We've had a bit of snow up here in Leeds so I've been using the Aux Heater each morning and after doing so the X seems a little sluggish to start. It's not struggling badly (yet) and once its fired up its fine. I can't remember it doing it last year but it may be my memory and be normal but would like to check.

Any help appreciated as always.

s14matt · Post by **s14matt** » Mon Nov 29, 2010 9:54 am

I'm not sure if it's still the case but almost all Halfords stores have a battery health checking device that's used by the 'parts counter' staff. ( I know this cause I used to work at halfords). They can simply plug it onto the battery and it'll tell you the condition of the battery i.e. what the voltage and cold crank amps available.

You could always check the voltage but it could show 12 volts and the battery still be partially dead.

Hope this helps.

X5Sport · Post by **X5Sport** » Mon Nov 29, 2010 12:13 pm

Fully charged a car battery should show 12.6V DC on a meter +/- a few tenths for meter accuracy. On charge it should rise to around 14.4V DC. Nothing like a bit of very cold weather to find a battery weakness!

A cold battery may struggle to deliver the correct CCA - Cold Cranking Amperes - starting current to you and me, and they also take much longer to charge up. You need to do at least 20 miles with most of the electrical loads turned off just to put one starting charge back in.

If you battery is more than 5 years old then it's more than likely on the downward slope towards needing a new one. My X5's is nearly 6 years old and get's a bit iffy in Winter. I give it a long charge if it hasn't been used for any long journeys recently.

The proper battery test is to give it a try with a device that puts the battery under heavy load to see if it can sustain the output required. If it falls away quickly then a cell is dying and not holding charge properly. I think most of the modern testers check the internal resistance of the battery and draw less current than the good old high power resistors that we used to use (which effectively almost shorted out the battery!!).

paulbryson75 · Post by **paulbryson75** » Mon Nov 29, 2010 1:58 pm

Similar story - last week - used Auxy heater for first time this 'season' - car failed to start.... Jump started her, took her to the local Battery place. Though the battery showed 12.1v when stopped and 14v when running on their meter - which i thought was ok - they plugged in another device which indicated 'red' and he told me one cell was 'dead' and battery was done.... 94 quid later and car is not only starting better but have been giving the auxy heater a full 40 mins these past two mornings - brilliant!!! (the new battery also cured all the issues I was having with the auxy heater last week as well)
It was the original battery in the car - so at 8 years am sure was due replacement... If get 8 years out of the new one will be happy

BTW Apparently BMW recommend an 85ah Battery for the E53 X5 - i went for A 100ah unit after reading advice on other forums and especially with the auxy heater being power hungry think the extra bit of grunt is worthwhile.

PhilT · Post by **PhilT** » Mon Nov 29, 2010 4:52 pm

Cheers everyone, I thought there may be a voltage meter somewhere in the OBC but I guess not. Looks like it might be a new battery job then - will see what it's like in the morning, looking at the weather I reckon I'll be putting the Aux on again

ITBarbie · Post by **ITBarbie** » Mon Nov 29, 2010 5:59 pm

[quote=""PhilT""]Cheers everyone, I thought there may be a voltage meter somewhere in the OBC but I guess not. Looks like it might be a new battery job then - will see what it's like in the morning, looking at the weather I reckon I'll be putting the Aux on again[/quote]

Hi Phil

You can check as when you go into the hidden OBC menu it's on option 9. Press the button on the right just near your dials above the steering wheel and if you keep your finger on it depressed it will go into the hidden OBC. If you navigate to option 9 you will see the voltage displayed.

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PhilT · Post by **PhilT** » Mon Nov 29, 2010 7:14 pm

Cheers Penny, I've just given that a try - it went from 'Check Control OK' to 'Test-NR 01' then I can change the number but cant get anything more after that

ITBarbie · Post by **ITBarbie** » Mon Nov 29, 2010 7:24 pm

I'm doing it from memory. When you get the 01 you then press the other side and you will go up to 02 etc until you get to 09.

I will try and pop out and do it as I can't write full instructions

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ITBarbie · Post by **ITBarbie** » Mon Nov 29, 2010 7:30 pm

Here you go this is someone with far superior eloquence than I!!

http://www.xoutpost.com/bmw-sav-forums/ ... x5-19.html

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PhilT · Post by **PhilT** » Tue Nov 30, 2010 10:10 am

Cheers Penny

I'll give it a go later on.

Thanks again

fenj66 · Post by **fenj66** » Tue Nov 30, 2010 11:20 am

hmm, ive just tried the obc voltmeter test on mine as im suspicious of the battery as the aux heater is having a bit of trouble lately. the car starts fine tho even in these cold temps but the aux heater powers down after a couple of minutes.

anyway: with the engine off the volts show 12.0
starting the engine drops down to 11.8
and with engine running the volts rise to 13.8

does this sound like a bad battery to anyone?

paulbryson75 · Post by **paulbryson75** » Tue Nov 30, 2010 1:57 pm

feng66 - not bad - but its not 100% though. Perhaps there could be cell damage as well though. Should be upto 14.4v when running and would really want above 12v (near 12.6) when stopped.
My car was starting fine - unless i used the auxy heater.

Sanj · Post by **Sanj** » Tue Nov 30, 2010 2:02 pm

fenj66 go with a battery first - it will be the same(ish) cost to diagnose a fault on the heater.

I can get my local EuroCarParts and GSF to price match each other on a Bosch Silver Line battery at Â£73 (95Ah, I think).

Mine used to start without issue but I could tell on cold start ups it was sounding tired. So a new battery and the car and heater were sorted.

paulbryson75 · Post by **paulbryson75** » Tue Nov 30, 2010 2:10 pm

Bosch Silver Line battery at Â£73

Sanj - thats a bargain - Halfords quoted me 129 for the bosch last week

.
I went elsewere

still paid more than that though

Sanj · Post by **Sanj** » Tue Nov 30, 2010 2:40 pm

Yeah - I got one for the X last year (still have the invoice) and used that to get a quote from GSF for the other car. Looks like they hate being beaten by each other!

Just thinking of when to get it as the current battery on the second car is starting the car without more than 1 to 2 cranks before startup on a cold morning....

But I know it is original and 6 tears old, so not long now.

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