New battery or charger ?

catoutthebag

I've already done 7-8k miles since march. Use on motorway & high speed roads a lot. No heated seats. Use it 4-6 days a week. Guess ill go for the new battery option...

Norman_Castle

On previous few occassions I noticed it wasn't starting from cold immediately, taking 10-15 seconds

As above, if the battery can turn the engine over for 15 seconds its unlikely to be failing. Its more likely to be a cold starting problem.

catoutthebag

What is it then? Would a garage diagnose free? I don't have leads, charger etx

arcon5

If the engine is trying to turnover for 15 seconds then maybe the glow plugs or something?

Strider590

If it's more than a few years old, then at this time of year i'd replace it anyway, just to be safe. It's a darn sight cheaper than a tow home and the loss of a days wages.

catoutthebag

What do people mean by turn over?

Prior to this, 20% of the time I would need to turn the ignition several times to get it on

When it packed up, the car was parked on a hill, petrol was low & there was a chattering noise from under the hatch

Couple days ago I booked to see a garage tomorrow am to fit a battery. Should I get them to run a free diagnostics ? It's a local garage

forgotmyname

Turn over or crank over. Means is the engine spinning like its trying to start or just a clunk or nothing at all happening?

Turn the engine on and nothing happens or does it spin like normal but not starting?

Norman_Castle

On collection of my car from the garage, the battery was dead & needing jumping. It's fine now

On previous few occassions I noticed it wasn't starting from cold immediately, taking 10-15 seconds

Why was it at the garage?. Was this a problem before it went there? If its fine now why do you want a new battery?

What do people mean by turn over?

When you turn the key fully the starter motor turns the engine.This should normally happen for a second or two before the car starts.

When it packed up, the car was parked on a hill, petrol was low & there was a chattering noise from under the hatch

When it packed up?. What was the problem?.

Joe_Horner

A new battery may or may not cure your problems in the mid to long term. Sadly, the advice to "get one anyway" is based on the principle of "change things till it works" rather than any particularly sound technical basis.

The only way to know for certain whether a lead acid battery is still servicable or not is to charge it fully, allow it to rest for 24 hours or so, take electrolyte readings, then test it under load for internal resistance. That's not going to happen "while you wait", although many places will stick a flashy meter across it to show you that it's "dead, mate".

By far the best investment you could make right now is a cheap digital multimeter. You can pick them up for under a fiver.

Take the car out for a good run (or charge the battery fully if you can borrow a charger) then let it sit for a few hours to stabilise. Now measure the voltage across the battery. Fully charged it should read around 12.6 volts. If it reads below 12.4 then charge it some more.

Now turn on everything electrical that you can - ignition (DON'T start the engine), headlights (high beam), hazard warnings, fog lights, radio, heated screens, interior fan (on full) and anything else you can think of. This will put a load of 70 amps or so on the battery with a typical modern car - not quite as much as a proper load tester, but enough to do the job.

Measure the voltage again with everything turned on for about 30 seconds. If it still shows more than about 11.5 volts then the battery is fine, if it's below this it may be borderline depending on the size of battery and exactly how much load you've managed to put on it. It should also recover quite quickly (within a minute or two) to close to the original reading once you switch everything off.

Now turn everyting off and start the engine. Measure the voltage with the engine running - it should be back up above 12.6 even at idle, and go to about 13.7v if you rev the engine gently. If it doesn't then your alternator needs investigation and is far more likely to be your problem than the battery.

[Deleted User]

arcon5 wrote: »

If the engine is trying to turnover for 15 seconds then maybe the glow plugs or something?

Glow plugs on a petrol engine :huh: