Charging the battery

Faults and Technical chat for the Vauxhall Astra K
Optician
Posts: 5
Joined: Tue May 05, 2020 6:48 pm
Astra Model: ST Elite Nav 1.4T s/s 6spd auto
Astra Options: 18" alloys, spare, parking assist, remote keyfob
Astra Colour: Cosmic Grey Metallic

Re: Charging the battery

Post by Optician » Wed May 13, 2020 1:27 pm

It's been bit of a saga but it's finally on charge. I've included some pics for clarity and for anybody who visits the thread with the same query in the future. You can see in the pictures that those terminals mentioned earlier are normally covered, and that cover has a smaller cover at its left end which exposes just the positive battery/charging point. For the negative, underneath that chassis screw that was referred to there is a hexagonal post which is there for the purpose of clipping on a charger or jumpstart lead. The last picture shows the leads in place and charging. So after all my worrying about it, it's as easy or easier than it's always been. If you have a start-stop model, just make certain your charger is capable of AGM charging, and configured for it before you start.

I'm not sure what the outcome wiil be though. A 15 minute run produced the same result as 20 minutes tick-over. It increased from 11.8V to 12.2V as measure with a (checked) voltmeter that plugs into the cigar lighter/power outlet. When running, it was measuring 14.9V so the alternator is shoving out plenty of volts, I don't know what current it is putting out though and I'm not sure if the battery is taking much of it. 10 hours or so under charge may reveal something.

Optician.

Astra_Mk7_charging_03.png

Astra_Mk7_charging_02.png

Astra_Mk7_charging_01.png


Bogbody
Posts: 123
Joined: Wed Oct 17, 2018 6:57 pm

Re: Charging the battery

Post by Bogbody » Wed May 13, 2020 3:23 pm

Which charger have you used?
At 1A (for example) the battery could take 2 days to fully charge.

Bogbody
Posts: 123
Joined: Wed Oct 17, 2018 6:57 pm

Re: Charging the battery

Post by Bogbody » Wed May 13, 2020 3:46 pm

Which charger have you used?
At 1A (for example) the battery could take 2 days to fully charge after a short run and a couple of starts.
The Oxford maintenace charger on my wifes car is showing 13.0V with no charge current so its on float charge. After a 6 mile run to the shops and 2 starts it takes a full day to day and a half to get to float voltage. Thats at a charge current of 840mA (0.84A). So, its putting some 30/35Ah into a 60Ah battery. Shows you just how much juice a couple of starts takes out!

BRUCE225
Posts: 212
Joined: Wed Nov 15, 2017 7:11 pm
Astra Model: ASTRA SRI VX-LINE NAV
Astra Colour: DEEP SKY BLUE

Re: Charging the battery

Post by BRUCE225 » Wed May 13, 2020 4:47 pm

He's using Noco 7200 according to the first post so 7.2amp. I have the same charger and put mine on charge once a week in lockdown with 3 to 4 starts a week and around 15 miles covered in total,it takes about 10-15 minutes to float, but mines not a stop/start.

Optician
Posts: 5
Joined: Tue May 05, 2020 6:48 pm
Astra Model: ST Elite Nav 1.4T s/s 6spd auto
Astra Options: 18" alloys, spare, parking assist, remote keyfob
Astra Colour: Cosmic Grey Metallic

Re: Charging the battery

Post by Optician » Thu May 14, 2020 11:50 am

Yes, Noco G7200. It had 6 hours yesterday and ended with charger showing 75% led on and 100% led flashing. It was at around 12.9V afterwards. 16 hours later it has gone down to 12.4V. Put the charger on again and it is fairly quickly gone up to about 75% charge. Will leave it today and see what happens, but theres no doubt that the Astra K has quite a static drain on the battery, plus whatever battery problems I may have.

Somehow I need to check if the alternator is putting out current. My wife plugged the power outlet voltmeter in when she took it for a run last week. It got dull, the dipped headlights came on automatically (halogens, not LED), and the measured voltage dropped from 14.9V to 14.8V. I would assume that means the alternator is putting out current, but again I'm not au fait with modern cars.

I'll certainly be charging it regularly from now on. I don't know how we got away with it before, with the car getting used so much that it had accumulated 650 miles at the first annual service!

Optician

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