Battery power question

[thegoal007]

I checked my battery with a voltmeter and found when the engine is being turned over to start the battery drops down briefly to 7.5 V from base reading of 12.5 V. I read in most places this is not good.
When the car starts its running 14.4 V and even under fully load (everything electric on) it goes down to about 14.2 V - I should expect it to be very good having refurbished the alternator less than a year ago.
I have also found out there is .02V draw from the battery- which I am assuming is negligible and probably from the led clocks.

Is my test conclusive to state the battery has a potential issue - bearing in mind a lot of my journeys are quite short - I only covered about 900 miles last year...and for the last number of x years it's been hovering between 700-900 miles p.a.

Or are there any other tests I can perform?
The reason I ask is because recently I found the car struggling to start week on week and finally not turn. Charging the battery (intelligent trickle charger) seems to to take me to the beginning of the cycle - i.e starting strong and over a few weeks get weaker.
As I have just bought the voltmeter, I will monitor the battery every week just before I start it and once I have finished my journey.

 

[desertstorm]

Sounds to me like you are not doing enough miles to recharge the battery to a good level. when you start the car you will need to drive it for a few miles to put back the energy used to start it. After that then the battery will actually be charging. If you leave the car for long periods without using it the battery discharges and as you have found overall the battery will discharge over a period of time.
Also the capacity of a battery drops over time , typically a good battery such as a Varta / Bosch probably has only 60% of the capacity it had from new after 4-5 years.
The alternator sounds good, how old is the battery? .

Karl.

 

[thegoal007]

Went to start the car today and it just about made one turn. I think the battery has had it. voltage reading about 11.6.
Popped to euro parts today and got the exide premium 4 year guarantee one at £68. When I picked it up it had a green light in the display. When I got home, it was off. The battery was on an uneven surface/tilted whilst in the boot of the car. I have put it on the trickle charger and I will fit in tomorrow unless the green light does not come on then I may have to return it!

The battery I originally had about 6 months ago, was given me by someone supposedly nearly new!
The previous one I had was the Bosch 3 year - it lasted well at 6 years - bearing in mind my mileage.

 

[GeorgieS3]

Would you recommend the battery you baught mate? Same thing has happend to me and garage are ordering one for me. I might ask them to get this one with 4year garranty?

 

[thegoal007]

tbh, it's a known good brand backed up with a 4 year guarantee. I could have bought the Bosch 3 year warranty (coincidentally called the S3!) one which was fiver cheaper, but I thought what the heck!
I have had that same Bosch one previously and that lasted 6 years lets hope this one does the same.

I just charged the new battery fully and disconnected it. Measures 12.88V full. My only slight concern is the display on the battery is still dark, which according to the display means discharge (not exactly sure how to interpret that)

 

[GeorgieS3]

Ok

tbh, it's a known good brand backed up with a 4 year guarantee. I could have bought the Bosch 3 year warranty (coincidentally called the S3!) one which was fiver cheaper, but I thought what the heck!
I have had that same Bosch one previously and that lasted 6 years lets hope this one does the same.

I just charged the new battery fully and disconnected it. Measures 12.88V full. My only slight concern is the display on the battery is still dark, which according to the display means discharge (not exactly sure how to interpret that)

Thanks for that. Mine went dead last week after accidentally leaving interior light on . And then completely flat this morning. The battery is 6 years old I think. So it just not holding charge. New one ordered rest for when I get home!