Battery seems to die

[Jo]

I wonder if anyone could help, please?  I have a '53 reg Jazz and replaced the battery about a year ago.  Today, when I picked up my daughter from school the car windows were all fogged up from the rain, hailstone and snow.  I switched on the heaters and air conditioning for about 5 minutes in order to clear the windows.  When I then turned the key to start the engine the battery was practically dead and I had to wait about 15 minutes before trying again and then it started ok.  This is about the 3rd time this has happened to me over the past year.  Am I doing something wrong?  Is the engine supposed to be running, even though I am stationary, when I am trying to clear the windows with the heater and air conditioning?

Any help would be gratefully received (preferably with no technical info, as I am in no way technically-minded).  Thank you.

[guest255]

Switching on the heaters and aircon etc.. without a running engine, of course the battery is gonna suffer.

Always have the engine running as it not only stops the battery going flat but the heat from the running engine helps clear windows etc..

[Jo]

Thank you very much JazzyB for your reply.  I won't make that mistake again!

[culzean]

The aircon certainly won't run with the engine stopped, because the aircon pump is run from the engine rotation. The heated rear window and mirrors will still work, and the heater fan motor will run, but will blow cold air because the water pump will not be pumping hot water into the heater matrix (water pump only turns when engine is running). I hope you didn't have your headlights and wipers on as well?

For your battery to go down so quickly (5 minutes) I am assuming that it was in a low state of charge anyway, short runs and local miles in the winter are not enough to keep the battery well charged, you need to do a decent long run (20 to 30 miles) at least once a week. If a car battery is continually kept in a low charge state (below 50%) it will die from sulphation, when the plates develop a white coating, the batteries do not usually recover from this and will not charge fully ever again.

Your battery needs to supply over 200 amps to start a cold engine, that's why its good policy to buy the biggest A/h battery that will fit your car.

[Jo]

Thanks culzean for the information. 

No, I didn't have either the headlights or wipers on.  Had the radio on though. Would I| need to have the engine running if I was parked up just listening to the radio without anything else draining the battery, e.g. lights, wipers, heating etc?

I don't do a lot of driving and yes, most are short runs.  However, I do one longish journey every week, approx 110 miles round journey.

I'll have a look in the morning to see if the plates have developed a white coating.

Thanks for your help.

[guest255]

If your just listening to the radio then engine off is fine, anything else then the engine needs to be running.

I doubt you'll be able to see the 'white coating' as most batteries these days tend to be sealed for life.

I would get it checked by a garage and replaced if necessary.

[culzean]

It's not so easy to look at the plates in a modern low maintenance battery as the cell filler hole covers tend to be hard to get off, sometimes there is even a sticker sealing them on.  You will not see much anyway, as the sides of the plates are not visible, only the tops.

The normal Honda Jazz battery is a 35A/h size with about 280 CCA but I managed to get a 40A/h in the space with 330 CCA (330 cold cranking amps, that a fully charged battery will supply at -18degC and still keep voltage above 7.2V), which helps a lot in the cold weather we have been getting lately.

Premium batteries with calcium or silver plate technologies offer much better performance than standard lead-acid batteries and should be considered for cars with auto-gearbox or CVT gearboxes because you don't have the option of push (or 'bump') starting the car if you find yourself with a flat battery.

[nowster]

Isn't there something about not push starting any car with a catalytic converter?

[culzean]

Good point about cat converter, if you get unburnt fuel into the cat it can cause it to overheat when the engine does fire up, usual advice is that if the car doesn't start up first try at bump starting its not advisable to keep trying it! 

Better if you can get someone with jumper leads to connect their battery to your battery (connect positive lead first then earth lead -if you connect the earth first you can easily short the 'live' + to you car body or engine and cause damage) and wait for a few minutes while the battery voltages equalise before trying to start the car.