I'm finding that when my car is unused for a week (holidays etc) the battery flattens completely. Trying to establish if I have a problem with the battery, whether something is still on (boot light etc or if the alarm & Navtrak are behaving abnormally. Trouble is I don't know what normal is, except that to lose all your security in a week is not a good thing.

Any idea what current these things should draw so I can check them?

Cheers

DT

I'll ask that bit in security might be someone in the know.

 

I don't know the exact current draw spec for the Sigma, but it should be around 15mA (0.015 amps) which won't drain a battery in good condition for two or three weeks at least. Navtrak, provided it has battery back up, doesn't actually draw any power from the vehicle's battery unless the ignition is on, and then it is only for charging the backup battery. You didn't say how old your battery is though. I have found that with electronics such as alarms etc constantly drawing current, 18 months to 2 years is the most you can expect from a battery before it's capacity is considerably reduced and its internal resistance increases which lowers its CCA capability. Also, short daily journeys take their toll very quickly on a battery. To keep a reasonable amount of charge in your battery you need to be doing at least 20 or 30 miles a day or the life expectancy of your battery will be reduced what with all that starting and not much charging. Lastly, sub-zero temperatures affect a battery's performance too, especially a partly charged old battery. It is very simple to find out whether the alternator is operating correctly. Start the engine and turn on the headlights to provide a bit of load, then using a digital voltmeter, the voltage between the battery terminals should be about 14.4 volts. Less than 14 would indicate your alternator needing attention (especially if this is so over about 1200 engine rpm's). Over 14.6 - 14.7 and your battery is being over charged which damages it, and again your alternator requires attention. If everything is ok with the alternator, it should be reading 14.4 ish volts from idle or just over throughout the rev band.

 

Thanks for the info Max. car was purchased in Feb01 new, although I think it was manufactured about July00. A bit early for a duff battery I would have thought. I'll get a meter and check the readings as you suggest.

cheers - appreciated.
DT

 

As posted in the other thread, my MY01 (registered 01 June 2001) is also doing the same.....also unused for week or more at a time