Thought about fitting an accessory gauge to the infotainment plate area in an upright pod,using usb port.I do not use it for phone or sat nav.Presumably,this socket is powered when ignition is on only,regardless of audio status .

I will check this out when weather permits,and use the two wires on a usb connector  to see if the meter will work (is it putting out 12v).I realise this info might be available via the phone,but my phone is not compatible anyway.Battery voltage seems to be important with these Greentech engines......

Edited 31 January, 20206 yr by Blackcountryman
AMENDED

USB is 5V.

Time for a rethink.......

 Check DC-DC converters.

 

Eg. https://www.amazon.co.uk/Converter-Qutaway-Voltage-Transformer-Booster-Black/dp/B071X6VYXR

 

 

I think the OP wants to fit a voltmeter to monitor the battery charge, no point in stepping up from 5v 😀

 

I have a small round black thing made for motorhomes etc, it has a USB port and an LED voltage readout and an on off switch, I fitted it to the centre console & wired it to the cigarrette lighter socket feed.

Oh, OK - the OP just said "a gauge" - it didn't occur to me that a voltmeter was worth fitting there, given, as you say,  there are 100's of cigar lighter plugins on the 'net that do that job!  I was thinking a gauge might need be illuminated by 12V whatever its function.....

 

And I image the stop-system is heavier on batteries than standard systems, so they probably will need changing more often. But the voltage is surely not something that needs monitoring all the time?

Edited 1 February, 20206 yr by freemansteve
added a sentence

After re-reading it many times I'm still not really sure!

 

As you say there are plug in voltmeters and plug in USB sockets, tried the latter & it looked really naff, I wanted both plus the facility to switch off the display so found something dedicated that fits the bill but needs a 38mm diameter hole.

 

Having had parasitic discharge problems, volt drop on starting causing fault codes & now a half knackered new battery my guage gets used all the time, The car may go several days without use but I can see the voltage from outside whenever i pass, when I start I watch the voltage guage and not the glowplug light, I wont crank until the voltage has come back up over 12v, it would start without but create fault codes.

Lots of possible root causes for the symptoms there!

 

How old is the car?

 

Assuming you know the battery is new-ish and 100% ok, it sounds like it is not charging properly. Or as you say, something seems to be draining it.  Most of the time, the battery is the problem, especially "off brand" batteries.

 

With greentech kit, the smart alternator tends to be fairly evident (actually with any smart alternator), and it should be obvious whether it is producing decent charge or not...  Drive around, get warmed up, then put your heater fan on full blast. Listen to the fan's speed. Now let the car coast downhill and let go of the throttle. The fan will likely speed up - this is because the smart alternator comes full on to top up the the battery (which is never fully charged if you are driving under power). It's a kind of energy recouperation thing. So, if this does not happen, I'd be thinking the alternator is not effective at charging the battery. A common cause of this is loose or corroded battery connections, or rusty earth straps on the body.

 

If not this, then have you fitted any electrical gear of any sort that may use battery power?

 

 

 

Quote

 

 

Edited 1 February, 20206 yr by freemansteve