Jump to content
House Price Crash Forum

Car Batteries


Recommended Posts

0
HOLA441
  • Replies 82
  • Created
  • Last Reply
1
HOLA442

Would anyone go to the trouble of changing a car battery at a particular age or just run it until you have problems/failure?

Depends on your circs, of course.

If it failing to start one cold damp winter morning is a major headache, change it.

I'm pretty sure you can test it's capacity as well in order to know if it's still ok, some last a lot longer than others.

Link to comment
Share on other sites

2
HOLA443

Would anyone go to the trouble of changing a car battery at a particular age or just run it until you have problems/failure?

You normally get some notice a battery is on the way out such as one morning it will struggle to turn the engine..

Batteries are susceptible to colder weather which is why many more fail in the winter as do the summer.

I would run it on till I was sure it was knackered before I changed it.. But ensure I checked the alternator was charging it first.

One quick and easy way is to start the engine and switch on the headlights. Stand in front and get an assistant to 'rev up' the engine. If you see a discernible change in the illumination of the headlights and they get brighter it is almost certainly charging.

If not get the charging circuit fixed first.....It could well save you a few quid on a new battery.

I have lost count of the number of friends who have complained about a battery and bought a new one only for that to go flat as well in a few days.

Link to comment
Share on other sites

3
HOLA444
4
HOLA445

There are three circumstances in which I would charge a car battery:

1) If I knew I had done something stupid like leave the lights on.

2) If I was doing lots of short journeys, especially in the winter. Starting the car pulls about 10 Ah out of the battery, and if you are simply driving 1 mile down the road with all the lights and fans on, the alternator is unlikely to have enough time to recharge.

3) If I wasn't planning to use the car for several months, I'd leave it on a trickle charger.

For pretty much all other situations, the alternator will charge it perfectly well.

Flat batteries are the biggest source of breakdown service call outs. If you are remotely suspicious of the battery, change it.

Link to comment
Share on other sites

5
HOLA446

If its your only car and you rely on it then premptively change it after 4 years I'd say.

If you have another car and can shrug off the inconvinience if it won't start on a cold day then just leave it til it goes then jump start til you buy a new one.

Depends alot on the car though. My mazdas have all had huge 60ah batteries that last for 5 years min. Whereas my mums punto has an teeny battery that has had to be replaced almost every two years.

Link to comment
Share on other sites

6
HOLA447
7
HOLA448

Do you have a multimeter?.

A few bits of info for you:

Charging at the mains is far superior for a battery's condition as opposed to being charged by the alternator, a proper 12hr charge by an intelligent charger will reduce the amount of sulphate buildup on the lead plates. I take my battery off to charge it in September & then again in early March time.

A fully charged battery should have a standing charge of 12.6v @ 20c. To properly test a freshly charged battery, turn the lights on for about 20 secs, switch off, then leave it alone for a couple of minutes, then test the voltage. sometimes you get what's called a 'surface charge' and it will basically make the results look better than they should be.

With the engine running, the voltage should ideally be 13.8-14.2v but it will vary car to car. As long as you see 13.5-15.5v you should be fine, the alternator is doing its job. To load the alternator, turn on the heater fan to max, headlights on full beam & the rear heated window and check to see if the voltage drops under 13.5v. (again with the engine running)

The above test doesn't really show up any diode failures in the rectifier, you need either to remove the alternator (or diode pack if that's possible) and test them or view the waveform on a oscilloscope. The latter option is the easiest because you don't have to remove anything, but scopes aren't cheap!. if one (or two) of the phases is buggered you get a spike in the signal, there's quite a few examples of this on the net these days. Basically it should be a simple sinewave, but with one phase out it starts to look more like a sawtooth

Quite often the alternator will continue to do a good enough job if one of the phases is knackered, but it can have a detrimental effect on the other electronic systems in the car - sometimes affecting things like the crank sensor (bad!).

To do a load test on the battery, remove the fuel pump fuse, hook the multimeter up to the battery & crank the car over for 10 secs. The battery voltage should not drop below 9.5v, ideally it should stay above that and be more like 10.5v. Anything less = battery unable to hold a proper charge

Link to comment
Share on other sites

8
HOLA449
9
HOLA4410

Do you have a multimeter?.

A few bits of info for you:

Charging at the mains is far superior for a battery's condition as opposed to being charged by the alternator, a proper 12hr charge by an intelligent charger will reduce the amount of sulphate buildup on the lead plates. I take my battery off to charge it in September & then again in early March time.

A fully charged battery should have a standing charge of 12.6v @ 20c. To properly test a freshly charged battery, turn the lights on for about 20 secs, switch off, then leave it alone for a couple of minutes, then test the voltage. sometimes you get what's called a 'surface charge' and it will basically make the results look better than they should be.

With the engine running, the voltage should ideally be 13.8-14.2v but it will vary car to car. As long as you see 13.5-15.5v you should be fine, the alternator is doing its job. To load the alternator, turn on the heater fan to max, headlights on full beam & the rear heated window and check to see if the voltage drops under 13.5v. (again with the engine running)

The above test doesn't really show up any diode failures in the rectifier, you need either to remove the alternator (or diode pack if that's possible) and test them or view the waveform on a oscilloscope. The latter option is the easiest because you don't have to remove anything, but scopes aren't cheap!. if one (or two) of the phases is buggered you get a spike in the signal, there's quite a few examples of this on the net these days. Basically it should be a simple sinewave, but with one phase out it starts to look more like a sawtooth

Quite often the alternator will continue to do a good enough job if one of the phases is knackered, but it can have a detrimental effect on the other electronic systems in the car - sometimes affecting things like the crank sensor (bad!).

To do a load test on the battery, remove the fuel pump fuse, hook the multimeter up to the battery & crank the car over for 10 secs. The battery voltage should not drop below 9.5v, ideally it should stay above that and be more like 10.5v. Anything less = battery unable to hold a proper charge

easier to replace the battery.

Link to comment
Share on other sites

10
HOLA4411

I'll add, you want to make sure all your connections (battery, alternator, fusebox supply & the earth lead(s) to the engine/gearbox/chassis) are good i.e. clean & tightly fastened. You should be able to see you face in them ideally!. Splodge a bit of vaseline or grease on the connections to protect them.

Link to comment
Share on other sites

11
HOLA4412

If its your only car and you rely on it then premptively change it after 4 years I'd say.

If you have another car and can shrug off the inconvinience if it won't start on a cold day then just leave it til it goes then jump start til you buy a new one.

Depends alot on the car though. My mazdas have all had huge 60ah batteries that last for 5 years min. Whereas my mums punto has an teeny battery that has had to be replaced almost every two years.

9 years my battery...but then...it IS a Toyota.

Link to comment
Share on other sites

12
HOLA4413
13
HOLA4414

I thought the miser's option of a £5 Maplin multimeter & a bit of time would be well appreciated on HPC! :lol:

there is a large price to pay for that amazing saving though....posters are too busy getting on with their lives to anything like maintenance...whether it be to the house or the car...

Link to comment
Share on other sites

14
HOLA4415

Keep it until it starts to fail. Primary cause of failure is sulphate build up on the plates, this happens primarily when the battery is left in a partially charged/discharged state. If your battery is beging kept charged up fully then it will last a lot longer than one that suffers significant discharge. Most modern lead acid batteries are sealed so the need to top up with acid no longer applies, but if your battery does require maintenance doing this will help to keep it running as long as possible too.

If you leave your lights on by mistake and find you cannot start your car don't keep on trying to start it. Switch off the lights, leave for half an hour and then give it another go - the battery given rest will regain its ability to push out a half decent current which should be enough to start.

Link to comment
Share on other sites

15
HOLA4416

Would anyone go to the trouble of changing a car battery at a particular age or just run it until you have problems/failure?

I knew my one was going when it started to labour to turn the engine over. This to me is the key issue.

If on a cold day (when the battery performance is at its poorest) and you've left it overnight it turns the starter motor slowly (and only you know what slowly means) then it is probably time to replace it. If the starter turns rapidly and the engine bursts easily into life then its probably OK.

Obviously if you are going to leave it standing for a long time then you need to take this into account as leaving it standing drains the battery (you should listen to its performance after x days of leaving it standing). Also you need to bear in mind the short run effect, in the respect that if you go for lots of short runs the battery will not necessarily have chance to fully charge after being drained, so if short runs are your thing the battery probably has to be in better condition.

Great thread that has taught me loads of things about car batteries that I never knew !

Link to comment
Share on other sites

16
HOLA4417

There's no reason to suspect a fault, it starts as well as it ever has and the only flat episode I've had is when the lights were left on all day, sometime last year. I am confident it will, like most things, be absolutely fine until the day it unexpectedly fails, completely and utterly fails.

But this will be its 7th winter and I would be prepared to replace it on the basis it would be prudent but it seems no-one else bothers and I shall wait for the Green Flag man (as I have in the past) before taking a trip to ECP. The marginal cost of replacing the battery every 5 or 6 years as a matter of habit is neither here nor there compared to other running costs (amortized over 5 years, it is less than a third of one percent of basic annual running costs).

Now who replaces their tyres when they only wear down to 3mm not the 1.6mm legal limit...

Link to comment
Share on other sites

17
HOLA4418
18
HOLA4419

This is a very timely thread, as mine expired a couple of weeks ago!

I was visiting relatives in London. Immediately after a 235-mile drive I parked the car about three streets from their house (they don't have a drive or garage, and so it's a case of wherever there's a free space within about a half-mile radius). The next day I went to start it to take them to Tesco, and the battery was so flat that even the digital clock on the dashboard had gone out. I hadn't left any lights on or any other source of power drain. A multimeter check revealed the battery to be as dead as Diana - 1.7 volts coming off it. As it was parked by the side of a busy road and nowhere near anywhere I could buy a new battery, I called the RAC (don't feel that guilty - first time in six years as a member). The RAC bloke confirmed my diagnosis and sold me a replacement for £75, which was in fact £5 less than I'd seen one in Halfords a couple of months ago. It comes with a four-year guarantee, and as I won't be keeping the car that long this was the perfect solution.

The expired battery was, as far as I know, the original one that came out of the factory in the car in 2001. I bought the car in 2007: none of the service documentation (which was complete: the previous owner appeared to have kept every bit of paper) recorded a battery replacement, and it was a Motorcraft (i.e. Ford OEM) one. My commute to work is 26 miles in each direction and the car almost never does short runs from cold. However, conscious of the fact that car batteries typically have a 3-5 year life, a couple of years ago I installed a volt meter (fed from the power supply to the radio) on the dashboard, which constantly read between the low 12s, up to about 14.25 throughout the intervening time.

And then suddenly, without any warning, difficulty starting, or any other indication that it was on its way out, the battery totally and utterly died. The night before had been an unusually cold one (there was a frost on the car when I arrived that morning), and furthermore was the first night in probably six months that the car had not spent in a garage. The RAC man said that this was a classic killer of old batteries, and he'd already sold a few new ones that morning to motorists in the same situation as me. But other than that, there was no possible of way of knowing that it was going to expire.

As a result of that experience I intend to be a proactive, rather than a reactive, replacer of batteries. In other words, when I buy a new (to me, i.e. used) car, then unless I know the age and provenance of the battery in there, I'm going to replace it immediately, and then again every five years, regardless of its performance at the time. In some ways it was sod's law that the battery went on the first day in six months that the car was away from my garage (and therefore I couldn't just walk to the Halfords half a mile away and get a new one), but if that had happened on, say, Christmas Eve and I'd had to wait for the RAC then, it would have been a very unpleasant experience: one which I'm very happy to pay £75 every five years to insure against.

Link to comment
Share on other sites

19
HOLA4420

There's no reason to suspect a fault, it starts as well as it ever has and the only flat episode I've had is when the lights were left on all day, sometime last year. I am confident it will, like most things, be absolutely fine until the day it unexpectedly fails, completely and utterly fails.

But this will be its 7th winter and I would be prepared to replace it on the basis it would be prudent but it seems no-one else bothers and I shall wait for the Green Flag man (as I have in the past) before taking a trip to ECP. The marginal cost of replacing the battery every 5 or 6 years as a matter of habit is neither here nor there compared to other running costs (amortized over 5 years, it is less than a third of one percent of basic annual running costs).

Now who replaces their tyres when they only wear down to 3mmm not the 1.6mm legal limit...

I always replace batteries every 7 years. I find that they are not so reliable after that. I have two automatic cars so a push start is not an option. One car is a 4.2 supercharged petrol jaguar and the other car is a toyota landcruiser 4.2 turbo diesel. the toyota is a twin battery 24v start and if one of the batteries starts to drop its not possible to start it. I also carry a powerpack in each vehicle as an emergency start option together with a set of jump leads.

I replace the jaguar tyres at 4mm because its a high performance car and I need the grip. I replace the toyota tyres at 5mm because they start to harden about then after giving 90k miles of service. The combined age of both cars is 32 years so with lower running costs I can afford to be more generous on consumables such as batteries, tyres, exhausts and brakes.

Link to comment
Share on other sites

20
HOLA4421

This is a very timely thread, as mine expired a couple of weeks ago!

I was visiting relatives in London. Immediately after a 235-mile drive I parked the car about three streets from their house (they don't have a drive or garage, and so it's a case of wherever there's a free space within about a half-mile radius). The next day I went to start it to take them to Tesco, and the battery was so flat that even the digital clock on the dashboard had gone out. I hadn't left any lights on or any other source of power drain. A multimeter check revealed the battery to be as dead as Diana - 1.7 volts coming off it. As it was parked by the side of a busy road and nowhere near anywhere I could buy a new battery, I called the RAC (don't feel that guilty - first time in six years as a member). The RAC bloke confirmed my diagnosis and sold me a replacement for £75, which was in fact £5 less than I'd seen one in Halfords a couple of months ago. It comes with a four-year guarantee, and as I won't be keeping the car that long this was the perfect solution.

The expired battery was, as far as I know, the original one that came out of the factory in the car in 2001. I bought the car in 2007: none of the service documentation (which was complete: the previous owner appeared to have kept every bit of paper) recorded a battery replacement, and it was a Motorcraft (i.e. Ford OEM) one. My commute to work is 26 miles in each direction and the car almost never does short runs from cold. However, conscious of the fact that car batteries typically have a 3-5 year life, a couple of years ago I installed a volt meter (fed from the power supply to the radio) on the dashboard, which constantly read between the low 12s, up to about 14.25 throughout the intervening time.

And then suddenly, without any warning, difficulty starting, or any other indication that it was on its way out, the battery totally and utterly died. The night before had been an unusually cold one (there was a frost on the car when I arrived that morning), and furthermore was the first night in probably six months that the car had not spent in a garage. The RAC man said that this was a classic killer of old batteries, and he'd already sold a few new ones that morning to motorists in the same situation as me. But other than that, there was no possible of way of knowing that it was going to expire.

As a result of that experience I intend to be a proactive, rather than a reactive, replacer of batteries. In other words, when I buy a new (to me, i.e. used) car, then unless I know the age and provenance of the battery in there, I'm going to replace it immediately, and then again every five years, regardless of its performance at the time. In some ways it was sod's law that the battery went on the first day in six months that the car was away from my garage (and therefore I couldn't just walk to the Halfords half a mile away and get a new one), but if that had happened on, say, Christmas Eve and I'd had to wait for the RAC then, it would have been a very unpleasant experience: one which I'm very happy to pay £75 every five years to insure against.

Interesting that your battery has lasted so long. My wife has a 2001 Ka which she bought when it was about a year old and it still has the original battery. In the same time I've replace several in the Exige but the Ka is used most daus and the Exige maybe twice a week. In addition the little 1300cc Ka is a damn sight easier to start than the 100bhp per litre + Exige engine.

I read somewhere recently that when you buy a battery and you have a choice of say a 3 year warranty for the cheap version Vs a say a 5 year warranty for the more expensive version you do in fact get exactly the same battery. The only difference is an insurance premium for the longer warranty. Some batteries do last longer than others for no apparent reason.

Link to comment
Share on other sites

21
HOLA4422

Some batteries do last longer than others for no apparent reason.

It's mainly due to how they are treated during use, as someone else stated earlier on. Lots of stopping/starting, short journeys and allowing the car to sit for weeks with the battery discharging will vastly shorten its life.

If any of the above applies, I'd personally recommend to remove the battery (or at least disconnect it) and recharge via the mains every 3 months or so - ideally overnight.

Link to comment
Share on other sites

22
HOLA4423

The more time a battery spends at less than full charge and the deeper it is discharged, the shorter it's life will be. My resource depleter was a natural battery killer until I re-programmed her. She had a tendency to turn off the engine and sit with the lights on going through some handbag centric ritual for a few minutes before switching them off and exiting the car.

Link to comment
Share on other sites

23
HOLA4424

...allowing the car to sit for weeks with the battery discharging will vastly shorten its life.

Interesting. Since the summer of 2009, mine has done 2-3 periods of 3-7 weeks a year sitting unused in the garage, while I've been in America. Maybe that helped to hasten its demise. It always started without a fight after I got back, though.

Link to comment
Share on other sites

24
HOLA4425

Interesting. Since the summer of 2009, mine has done 2-3 periods of 3-7 weeks a year sitting unused in the garage, while I've been in America. Maybe that helped to hasten its demise. It always started without a fight after I got back, though.

For about £40 you can get special chargers that keep batteries topped up, they also have charging characteristics that also help prevent / even cure sulphation. worth it if expeecting to keep a car in storage for any period pf time 9used a lot for bikes).

The other thing is not all batteries are created equal, could have had a bit of a cheapy, problem is the really good ones are priced accordingly.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.




×
×
  • Create New...

Important Information