How to kill a car battery

theatretony

Odd question for people.  My stop/start has stopped working and even if I drive 400 miles, if I turn off the engine and just listen to the radio, the low battery warning comes up.  I have a device that plugs into the cig lighter and when engine is not on it is around 11.9v but when the engine is running it is over 14v

The car always starts first time, just the issue with the Stop/start and the low battery warning.  I guess it is time to get a new battery, however, I pay for RAC and have the battery replace option.  At the current time, I guess they would not even entertain it as the car starts.  I know this is not the 'correct way' to get a new battery, but is there a way to kill the battery so it cannot be recharged so RAC have to replace it FOC.....

Cheeky way of doing it, but I have just paid out for a new clutch and flywheel, so money is tight at the moment!

Ebe_Scrooge

Probably the simplest way is to completely flatten the battery a few times - leave your headlights on for a couple of hours, flatten the battery, recharge it, rinse and repeat a few times.  Most batteries don't like being completely discharged, they get all huffy and refuse to hold a charge after a while.

theatretony

Ebe_Scrooge said:

Probably the simplest way is to completely flatten the battery a few times - leave your headlights on for a couple of hours, flatten the battery, recharge it, rinse and repeat a few times.  Most batteries don't like being completely discharged, they get all huffy and refuse to hold a charge after a while.

I do not have the equipment to recharge it, and if i take my keys out and lock the doors the the headlights will turn off automatically!!

Ebe_Scrooge

Remove it from the car and short out the terminals with a spanner or such-like?  Odds on that'll knacker it pretty quickly

daveyjp

Just because a battery is showing healthy voltage doesn't mean its healthy.  For that you need to test how well it provides the current required to start the car.

facade

Ebe_Scrooge said:

Remove it from the car and short out the terminals with a spanner or such-like?  Odds on that'll knacker it pretty quickly

Don't try this, if the battery is any good you will have a lovely impression of the spanner burnt into your hand.

The battery isn't holding a full charge, or the voltage would be higher with the engine off.  The RAC battery replace seems to be worded so they never have to do it.

You must be broken down with a battery that wont start the car, it mustn't accept a charge, but it must not show any signs of abuse, and you must have followed their recommendations- probably to buy a new battery when they came and started the car the day before....

Grumpy_chap

facade said:

 The RAC battery replace seems to be worded so they never have to do it.

You must be broken down with a battery that wont start the car, it mustn't accept a charge, but it must not show any signs of abuse, and you must have followed their recommendations- probably to buy a new battery when they came and started the car the day before....

I agree, but I got one.

The battery was pretty much on the way out when I took out the cover.  Limped until February, then called out RAC with a totally dead battery.  

Response was slow, called them on Friday and they arrived Sunday, but I was at home so not too bad.

The Recovery Technician was quite quick to try to sell me a £280 battery, so I said "thanks - why isn't the replacement covered under battery replace?"  He grumbled, then got on with it.  Best £18 ever - though I think the cost has increased now.

I had to time things as you have to be on cover a certain period plus the vehicle under an age limit.

theatretony

As per RAC:
If we attend a breakdown under sections A (Roadside) or B (At Home) and the cause of the breakdown is a fault with your vehicle’s starter battery, and we cannot get it recharged because it is unserviceable we will:
1. Fit a new battery; and
2. Dispose of the battery that we have replaced;

Not covered
1. Batteries that need to be fitted by a manufacturer or garage;
2. Electric or hybrid vehicles, motor homes, kit cars, quad bikes, modified or imported vehicles;
3. A breakdown caused by an incorrect or incorrectly fitted battery;
4. Batteries that have been misused or abused; or
5. Any breakdown relating to a fault that we have already attended and
a. the original fault has not been properly repaired; or
b. you have not follow

So looks like it has to be REALLY dead to get them to do it..

Ibrahim5

All sounds a bit crooked to me.

Flight3287462

I have just replaced my stop/start battery thought it was going to die last winter 20/21 if felt a lot better last summer but this winter it really was not enjoying life to the extent I was getting error codes for very strange things.  I was 11.9V  when I changed mine your story sounds very similar to mine.  Car 2016 Skoda Superb is feeling a lot better all error codes gone and the car is working well again.

After a lot of research I bought mine (a Varta) from the battery group for £120.  (Varta = Bosch)

shiraz99

Flight3287462 said:

I have just replaced my stop/start battery thought it was going to die last winter 20/21 if felt a lot better last summer but this winter it really was not enjoying life to the extent I was getting error codes for very strange things.  I was 11.9V  when I changed mine your story sounds very similar to mine.  Car 2016 Skoda Superb is feeling a lot better all error codes gone and the car is working well again.

After a lot of research I bought mine (a Varta) from the battery group for £120.  (Varta = Bosch)

Did you get your battery registered/coded?