What would be classed as low battery voltage ?

I have a sprinter van battery on my 2007 FL2.
It show 12.8 volts and 14.2 charging when running. Im getting the HDC warnings when i start the car, reading on here there is a lot of comments about low voltage.

The battery was new old stock and given to me 2 years ago so i cant complain if its getting tired.

Hello, Someone put on this forum regarding adding an extra earth cable from the negative earth post to the engine block to cure hdc issues when starting, just put earth cable into search. Or hdc fault.
I have or had similar issues before I joined the forum, I put a “AGM” advanced glass mat type battery on my 09 FL2 the same spec of an Evoque as fitted by factory, this cured my hdc issue, but I have since done the cable mod from battery to one of the starter motor bolts as I have experienced some poor cold starting, this cable I think is the cure.
Try it
Just to add tho when using the cables I measured mine and had a auto electrical shop to crimp the large ring terminals to the cable as it looks more professional but also think of the amperage from battery to engine block

I also cleaned up all the earth connections to the body anyway as not to cause a short somewhere.

Done the earth lead thing soon as i got the car, ive recently run another earth lead from the same gear box bolt back to another point on the body, cleaned all the earth points i can find as well.
Fitters at work think 12.8 volts should be plenty and the battery drop tests ok.

Well, regarding the current battery what is the amperage? A standard 096 battery is 70Ah, my Evoque battery is equivalent to an Exide AGM 115 80Ah.
If you have the cable mod plus cleaned all others wonder if the starter motor is pulling too many amps, I remember once an AA patrol used a jump pack to start mine when the mrs on a cold day had seat heating, rear screen, heater and lights on, the battery was the original this event was when the car and battery was three years old, this was the second call out, he condemned the starter motor which fortunately was replaced under good will warranty and I replaced the battery to a Bosch 096 80Ah. Also during the 2nd call out the hdc warning came on and he said the starter motor is drawing far too many amps that the battery can manage

It’s a bit dawnting but charge your battery to full, attach the multimeter and see what the voltage is cranking from cold.
As a test I have put mine on charge now, I use a Noco genius G7200 battery charger hence the AGM battery and in the morning 1st thing will do the multimeter test and report the readings back.

Hope this helps?

Hello, sorry for late reply here are my findings, I charged the battery overnight and removed the charger and waited an hour or so for the battery to settle.

Standing voltage 12.45 volts
Ignition on and after air bag light off stable at 12.03 volts heater motor on 1st speed and drivers door open.
Cranking 11.35 volts
Engine running 14.46 volts
All consumables heated rear/front screen on, heated seats and lights inc fogs 14.30 volts.

You could try inspecting the cable/terminal condition on the starter motor connection and a clean up, failing that though possibly a starter motor issue. A slow crank plus cabling or a duff battery would put the hdc light on especially cold.
I can remember that before the AGM battery the voltages were slightly less as I compared the usability of an AGM battery.
My Fluke multimeter is a month after calibration so it’s quite reasonably accurate

I suppose other forum members will compromise my readings...!

You should let the battery sit quietly for 24 hours, 12.45v is too low, sounds like the battery is on crutches, around 12.7v would be better. 12.8v is good.


New "old" batteries age from the day are manufactured & they will age even a bit quicker if not charged every month. Lead acid batteries like to be kept fully charged. Procrastination, mankind's greatest labour saving device!

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