Safely test car battery

Buzzard1985

cymruchris said:

Buzzard1985 said:

MX5huggy said:

You won’t have issues with lights, well not before the car won’t start. Is the car starting as it always has or is it a bit sluggish? 

Batteries wear out they don’t like the cold, after about 5 years you can expect to replace them. Look at the cost of a replacement from Tanya Batteries.

No the car starts fine- never been an issue.  Couldn't tell you when the battery was replaced as second hand,  Somebody mentioned date code on the battery had a look can't see a date.   About £80-£100 for a new battery inc them dealing with the old one asI imagine local council wouldn't recycle these-  right enough does make me wonder folk just throw them in landfill than have dealt with.  

There's good money in recycling batteries - although there are several types - most contain materials that are worth a bob or two. If the car is starting normally - as in the starter motor turning over sounds like it always has - then it's unlikely to be a battery. The clock reseting to zero might indicate a connection problem rather than a dodgy battery. For now - I wouldn't spend the money on a new battery - but if the clock resetting thing happens often, you might need an auto electrician to test all the various connections to see where the circuit break is happening. 

Find it stange all fine going into garage.  They replace starter motor and now I have this.

Grumpy_chap

Have you asked the garage?
They might be able to check things over and that there is no loose connection anywhere.

facade

Buzzard1985 said:

thanks I do 32 odd miles a day just for work.     Where is the date code- will have. a look the now.  Thanks for your help.

You will have to google it for your make of battery. Sometimes it is part of the serial number, sometimes there is an obvious date on a sticker, sometimes there is a code number melted into the case. You can assume it is at least as old as how long you've had the car, and if the car was under 5 when you got it, the battery is probably the original.

I'd likely order a new battery from Tayna or equivalent if the old one is a few years old and just have one less thing to worry about (unless it is a £150 battery )

You just take the old one to your council recycling facility for free- they are worth £5-10 as scrap anyway

Norman_Castle

My clock resets to zero after starting if it hasn't been regularly used and the battery is obviously low. How long after tthe failed starter and replacing it did this problem happen? Do your regular miles for a week and see how well the car starts.

clive0510

if you not exactly sure what you are doing, take it to kwikfit or halfords and get it checked out. they'll find the fault,give you a price, job done.

DiddyDavies

clive0510 said:

if you not exactly sure what you are doing, take it to kwikfit or halfords and get it checked out. they'll find the fault,give you a price, job done.

Take it to KwikFit or Halfords and there is a very good possibility that they will find a fault (or possibly multiple faults) even if one doesn't exist.
Neither KF nor Halfords will have anyone who is much of an expert in auto electrics and they do tend to simply replace items to see if it fixes the problem rather than actually investigating what is the root cause of the problem.

knightstyle

Do you know anyone with a multimeter?  If so just connect it to the battery and check the lowest voltage when you start the car.  It should drop a bit but IMO lower than 6 volts means the battery is on its way out.

Grumpy_chap

My battery is on the way out in my car and I manage to eek it out for a bit longer life by using a solar battery maintainer when the car is parked so it keeps enough to maintain settings and be able to start again.  Without that, the battery needs charging if left a week or so.  (I think there is something causing a drain while parked?)

Goudy

Grumpy_chap said:

  (I think there is something causing a drain while parked?)

You can test for this with a mulitmeter.
Turn everything electrical off (make sure the doors are closed so the interior lights are off, but leave a window open in case it trips the central locking)
Set a multimeter to amps (small scale) and remove a lead from the battery.
Bridge the gap between the battery and the disconnected lead and read what amps it's pulling with everything off.

You should see something very small, it's not uncommon to see around 0.05 amps being pulled if eveything is ok.

Anything much larger and you've a drain.
With a diagram of the fuse box (or boxes) pull a fuse at a time to see which causes the biggest drop, this is likely the circuit the drain is on.

The most common cause for a drain is aftermarket headunits being wired up incorrectly.
They usually have two live feeds. 
A store feed (to store the presets) that pulls little amps and the unit's main power feed that will pull a lot more.
The store feed should be a constant live but the unit's power feed should be switched or inhibited (switched live only with the ignition on or timed delay live from the ignition).
Wire up this power feed to a constant live and you obviously pull the power all the time, with the ignition on or off or the head unit being on or off. 
This can take enough amps out of the battery for it to fail to activate the starter relay in only a few days, making the battery appear flat.

Buzzard1985

I decided to just get a new battery- guy coming this weekend to fit. £95 
If I turned the lights on and the back screen on. turned on the engine- reset time.    Lights off etc on starting- appears to always remain the same time/miles.
So must be the battery.
Second-hand car- so unsure age of the battery.  Had a look on it and couldn't report back on this.
Partner raised two points.   First got it was fine within 24 hours we had to jump-start- push.   Put down to must been sitting before sale-naive.   Secondly.  I was sat with no engine just hazards as was directing traffic away from a flooded area.  The car failed to start on turning key.
So the battery is probably in need of landfill and a new one installed