I installed a new battery in my car just two years ago. That seems a bit recent for a battery to give out...
Is there an easy way to determine which is giving problems: the battery or the charging system?
TIA
DD
I am afraid sometimes that just happens - worst case seems to be car not used for long periods..
Check the battery voltage at the terminals using a DVM with the engine running at a fast tickover. Anything over 13.7 volts means your charging circuitry is probably okay. If it's lower, go for a run of about half an hour in daylight and repeat the test.
Or take it to your local Kwikfit or other battery shop who offer a free test, and ask them to put their tester on it.
Do the lights brighten when you run the engine? Or to put it another way if you turn the engine off do the headlights dim a bit? If so it suggests the alternator is working.
Fanbelt OK?
Is the daily journey long enough to recharge after the starter motor has been used?
When you fitted the new battery did you tighten the terminals enough? Could be worth checking.
If the battery is one where you can add water, does it need water?
A £5 voltmeter would be good enough to check if the alternator is providing a high enough voltage to charge the battery.
Voltage across battery with engine off, sidelights on: 12.5V approx. Voltage across battery with engine on and at a fast tick over, sidelights on: 14.6V approx.
Bill
Bill Wright wrote in news:jct7r2$enh$ snipped-for-privacy@speranza.aioe.org:
Thanks to all for the helpful replies. I am cuurently charging the battery, using my cheap battery charger. It only has one setting, and reduces its charge as the battery charges up. Can anyone tell me how long I can leave it thus charging? Is 15 hours too much?
Once the batter is charged, I will do some of the tests suggested (tomorrow).
DD
It's a long long time since I've seen 14.6v. Last probably with a dynamo.
What's the charger's output in amps, and what's the capacity of the battery in Amp Hours?
Have you by chance fitted an old style lead acid battery into a car which is intended to take a silver calcium battery? I would imagine that would over charge it and lose the electrolyte, although probably much faster than you are experiencing.
That's the first time I've heard of a car battery being anything other than lead-acid - except for electric vehicles of course, and historical things like NiFe. Silver-calcium - sounds expensive - tell me more...
Just to add to that, check earth connections from battery to body and engine to body.
snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote in news:jctbvv$jan$ snipped-for-privacy@dont-email.me:
4 amp charger and 95Ah battery.
Gosh - I don't know; the battery was chosen by a battery dealer who looked up a battery that was supposed to suit my vehicle, but they may have got it wrong.
DD
It's still lead-acid, but there's extra bits.
snipped-for-privacy@cucumber.demon.co.uk (Andrew Gabriel) wrote in news:jctbvv$jan$ snipped-for-privacy@dont-email.me:
4 amp charger ; 95Ah batteryI don't know. It was chosen by a battery dealer hundreds of miles from here, while I was travelling once. He selected it from some computer database as being suitable. That's all I know. The present battery is made by CBX and I can't determine the model just now. It's a 700 amp 95 Ah. The vehicle is a Mitsubishi Delica 1995 2.8TD auto 4x4 (Japanese grey import).
DD
There are glass mat batteries too, but I haven't looked at what's different about them. They are fitted to stop/start cars.
nt-email.me:
24hr charge then.
Well, tell or show us exactly what it says on the battery, and what type of battery your model should take, after googling for the info. Charging voltage also matters on the car - and perhaps on your charger too.
NT
15 hours at 4 amps = 60AH, so if the battery is 'flat' it sounds about right.
Bear in mind that modern cars have a lot going on even when the ignition is switched off and modern electrics can take a lot out of the battery. If you do short journeys in winter, you probably don't replace the energy used when starting. I left a car in an airport car park for two weeks and the battery had almost flattened itself in that time.
Can be charged at a much higher voltage (I think up to somewhere around 16V, but I haven't looked into the details). This has to be done in a much more controlled way, and therefore it's done when the engine management system is directly controlling the alternator output regulation in conjunction with setting the engine speed. One side effect is full alternator output at idle engine speed, because the EMS will supply the additional fuel to match the extra output it's telling the alternator to produce. The EMS also knows which loads are on (lights, wipers, etc), and uses this in calculating required alternator output. It also takes into account engine compartment temperature, because the high charging voltage is only used when the battery is cold. In the original smart charging systems, you could simply unplug the signal connection to the alternator and the whole system fell back to conventional lead-acid alternator system, but I don't know if that's still true today.
Ford have done this for a long time, even on the most basic models. I don't know which other manufacturers use ilver calcium smart charging.
I *assume* my battery will be flat after 2 weeks in winter, and leave the jump leads and a pair of gloves handy in the boot for return. Borrowing a jump from another car is a simple 5 minute job if you have the equipment, and much preferable to waiting an hour for the RAC or airport to help you
I've kept jump leads in my car for years. They usually can be fitted in the spare wheel compartment. Of course, modern cars make it difficult to get at teh abtterry connections without tools - so you need those, too.
If it's 2 years old it is probably still under warranty. I had one die on me over the intensely cold spell at the end of 2009-2010 when the car was iced up for 3 weeks solid. The battery shop checked my alternator was putting out the correct voltage and when they saw that it was, replaced the battery without any further questions.
Do the lights brighten when you run the engine? Or to put it another way if you turn the engine off do the headlights dim a bit? If so it suggests the alternator is working.
Fanbelt OK?
Is the daily journey long enough to recharge after the starter motor has been used?
When you fitted the new battery did you tighten the terminals enough? Could be worth checking.
If the battery is one where you can add water, does it need water?
A £5 voltmeter would be good enough to check if the alternator is providing a high enough voltage to charge the battery.
Voltage across battery with engine off, sidelights on: 12.5V approx. Voltage across battery with engine on and at a fast tick over, sidelights on: 14.6V approx.
Bill
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