Flat battery /RAC /Halfords

[Rewulf]

14 hours ago, rbrowning2 said:

These battery testers are ok but not the best, they simply put a load on the battery similar to an electric fire element and then reads the voltage, so if not fully charged at the time of the test can give misleading results.

They simulate the load of a starter motor turning an engine over.
If the voltage drops on the gauge as you use it, then the battery is either a, at the end of its useful life, or b, discharged and could be recharged and bought back to life.
The reason its discharged could be multiple issues, there could be a fault with the cars electrics, dodgy relays ect, i quite often discovered an interior light had been left on.
Sometimes the alternator was undercharging, or indeed overcharging, which 'boiled' the battery.

There is much talk about the car not being driven enough, so the battery went flat.
This makes little sense if the battery is in good serviceable condition, I had batteries on the shelf that had been left uncharged for YEARS, they went on a vehicle and started straight away.
Ive also owned 100s of cars, some not used for months at a time, 9 times out of 10 you could jump in them and start them fine after this.

15 hours ago, rbrowning2 said:

Feel your frustration, give it a good charge with a battery charger and if it then goes flat within a week  probably just simpler to replace it.

That would be a good idea, but....
If it goes flat within a week, there is either something seriously wrong with the battery, or a serious drain on the car. A simple multimeter test on the car would indicate this, which no one seems to have done.

No car manufacturer stipulates the car must be used on a regular basis to maintain battery capacity,

[Red carp]

On 16/02/2025 at 17:18, steve_b_wales said:

Thanks. I did look into getting a trickle charger for her car, once we get this issue sorted. Which model CTEK have you got?

Hi Steve, mine is for start/stop battery’s CT5 I think, if I bought another smart charger don’t think I’d buy a CTEK as they have gone crazy money now far cheaper smart chargers out there 👍

 

 

Edited Monday at 20:00 by Red carp

[udderlyoffroad]

On 17/02/2025 at 13:08, Rewulf said:

There is much talk about the car not being driven enough, so the battery went flat.
This makes little sense if the battery is in good serviceable condition, I had batteries on the shelf that had been left uncharged for YEARS, they went on a vehicle and started straight away.

But the question is; how much driven?  If the vehicle only drives a few miles to the nearest shop, in winter, with the fan, lights, heated rear screen etc all running, and then not used till the next week, where it does the same journey, that will kill a battery.  If it's driven 30+minutes including a few miles at the national speed limit, on the other hand...The OP alluded to the fact that the use case was more the former than the latter.

I would have agree that a bad battery is usually a symptom rather than a route cause.

Anyway....4 pages of this and the OP seemingly hasn't bought a a replacement battery.

This is the 'trickle charger' I use, it has revived otherwise dead ex vehicle batteries used on our DIY syndicate's fox wires.  It takes a few days for a really dead battery, but it will take on batteries that other, meatier chargers, will not touch and fault out:

https://www.amazon.co.uk/gp/product/B0828HMG3N/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[steve_b_wales]

5 hours ago, udderlyoffroad said:

But the question is; how much driven?  If the vehicle only drives a few miles to the nearest shop, in winter, with the fan, lights, heated rear screen etc all running, and then not used till the next week, where it does the same journey, that will kill a battery.  If it's driven 30+minutes including a few miles at the national speed limit, on the other hand...The OP alluded to the fact that the use case was more the former than the latter.

I would have agree that a bad battery is usually a symptom rather than a route cause.

Anyway....4 pages of this and the OP seemingly hasn't bought a a replacement battery.

This is the 'trickle charger' I use, it has revived otherwise dead ex vehicle batteries used on our DIY syndicate's fox wires.  It takes a few days for a really dead battery, but it will take on batteries that other, meatier chargers, will not touch and fault out:

https://www.amazon.co.uk/gp/product/B0828HMG3N/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

True, the reason being is that her car is getting a good run daily just to see if it will make a difference. A new battery will eventually be purchased though.

I use mains operated trickle chargers for my 12v lamp and flapper batteries. I think we'll also get a solar powered one and fit it to her car, but will make sure that she, or some of the family, make more use of her car.

Edited Wednesday at 14:17 by steve_b_wales

[shaun4860]

9 hours ago, steve_b_wales said:

True, the reason being is that her car is getting a good run daily just to see if it will make a difference. A new battery will eventually be purchased though.

I use mains operated trickle chargers for my 12v lamp and flapper batteries. I think we'll also get a solar powered one and fit it to her car, but will make sure that she, or some of the family, make more use of her car.

My next door neighbour has just had her car mot’d

Distance travelled in last 12 months?

37 miles!

It passed 🤣

[Bigbob]

16 hours ago, shaun4860 said:

My next door neighbour has just had her car mot’d

Distance travelled in last 12 months?

37 miles!

It passed 🤣

My mates was the same he drives a disability car all the time But his failed for cracks in the tyres due to lack of use LOL