Member Since: 23 Feb 2006
Location: Gold Coast, Australia
Posts: 867
Hi Dave and your voltage reading in the morning is the most important one.
At 12.2v, your battery is in need of a good charge and not just a few hours driving.
While cranking batteries will function adequately with a settled voltage reading of 12.2v and thats a battery with a state of charge of around 60%. But that indicates a fair bit of battery capacity has been lost.
Continually having your battery in such a low state of charge will shorten the battery’s life span.
At 15.06v at idle, shows your alternator is fine and I would suspect you would probably see around the 15.5v while your were driving.
Because of the vehicle’s own electrical requirements, idle voltage is not an accurate indication of the actual operating voltage.
If you have a multi stage battery charger, try charging the battery overnight every two or three nights for a few weeks and you may be able to recover some if not most of the lost capacity in your cranking battery.
This can in turn increase the life expectancy of your cranking battery.
If you haven’t got a battery charger and decide to get one, get a small one, say around the 10 amp mark. Small chargers ( low charge currents ) are far better for batteries than high current charging.
Again, if you charge the battery, leave the charger on the battery for at least 10 hours. Many people make the mistake of disconnecting a battery charger when the charger goes into float mode, thinking the battery is fully charged.
Leaving the battery in a float charge for up to 8 hours will not only fully charge the battery but it will condition the battery.
It’s the conditioning of a battery that can recover some of the lost capacity. But it can take quite a few long chargers before you notice an improvement in the battery’s rested voltage.
This chart should be of some help with your rested voltage readings.
Click image to enlarge
2008 TDV8 RR Lux + 2009 D4 2.7
13th Nov 2013 2:38 pm
Dave^
Member Since: 23 Jun 2013
Location: West Yorks
Posts: 706
It was hooked up to my ctek for just over 24hrs, showed fully charged after a couple of hours...
Member Since: 23 Jun 2013
Location: West Yorks
Posts: 706
RAW wrote:
Dave I use one of these pity you are not closer as I would have met up and done it for you,
No worries pal, I'm meeting up with my new BFF on Saturday, aren't I Geoff? flickr
13th Nov 2013 7:53 pm
drivesafe
Member Since: 23 Feb 2006
Location: Gold Coast, Australia
Posts: 867
Hi Highland and they are not going to give you an accurate voltage reading.
Anything connected to the vehicle’s power supply, anywhere in the vehicle, can have an effect on that type of devices voltage reading.
I have seen up to a volt difference in what something like that displays in the cab and what a multi meter displays at the cranking battery terminals.
They are handy for letting you know the alternator is working but the readings can be so far out that they no real indication of the voltage at the cranking battery’s terminals, which is what you really need to know.2008 TDV8 RR Lux + 2009 D4 2.7
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