Mag charger port operation

[andrewdj]

Can someone confirm please. If I test voltage at the two terminals on the mag port, it reads 0V. When I attach a magnetic charger cable and test at the end of the leads it reads 12.2v. I’m assuming the mag port needs to detect a connection before routing a connection to the battery?

[LTP]

Correct. There is a switch within the magnetic port that ensures the terminals aren't "live" unless there is a compatible plug magnetically attached

[andrewdj]

LTP said:

Correct. There is a switch within the magnetic port that ensures the terminals aren't "live" unless there is a compatible plug magnetically attached

Cheers LTP.

[LTP]

andrewdj said:

Cheers LTP.

No problem. The only other comment I’d make is 12.2V seems a bit low - I’d expect more like 12.6V from a good, charged battery, and 13.4V if the engine is running. There could possibly be a poor connection in your system.

[andrewdj]

I haven’t driven it any considerable distance in over 2 weeks and maybe 200-300 metres last week after cleaning it to dry out the brakes. It could be that the battery is on the way out but I’m struggling to determine. I had it tested and the verdict was a faulty trickle charger and the battery and charging system is fine; but after returning the charger that is reported as fine! So the answer is….I don’t know, but I’ll do some more investigation. Maybe I’ll just change the battery anyway.

[LTP]

I changed my battery at 6 years old just because I know how much Astons hate low voltage batteries. Mine was still starting the car, but the condition monitoring lights on my (not CTEK) conditioner showed an improvement with the new battery fitted.

One check you could do, if you haven't already; measure the voltage at your mag port, then immediately measure the voltage directly at the battery terminals - it should be pretty much the same. Any significant difference is worth investigating

[andrewdj]

I did that actually: both read exactly the same. Hopefully get my charger back today so I will try it again at the mag port, with a new cable, and at the terminals under the bonnet and see what happens. We’re going on a road trip in 2 weeks so I may just change it.

[andrewdj]

My charger plus new mag cable was returned today. Interestingly, the cable is only around 30cm and is a slightly different design in that it has a dust cap as well. The old cable was 1.5m to 2m long. I’m suspecting it was too long - I seem to recall that people using the CTEK extension cable could have issues. Anyway, been on all day and it ramped up to stage 7 with no problems whereas before it was stopping at stage 1 or stage 5. I shall give it a couple of days and see how it goes, perhaps even trying the old cable as well. It’s a shame as with the new cable I have to use an extension lead whereas the old one gave me enough reach.

I’ve not tried it yet, but will the extension lead go into the boot without damaging the seal? It’s about 10mm in diameter. I know the mag cable can feed out of the boot ok.