Civinfo - View Single Post - Flat battery 2.2 CDTi EX

3rd Honda · 7th January 2007, 14:55

Does anybody know what the alternator output is on the Civic (I assume CTDI and VTEC will be the same)?

The reason I ask is that there is a huge electrical demand:

Pre-heaters use many amps, albeit for only a few seconds
Diesel starter is a very heavy load
Heated rear windows and mirrors come on automatically
Headlights, etc
Heater on Auto runs the fan quite hard, and I assume the a/c compressor clutch
There has been rumoured to be an electric heater to assist quick warm up on the diesels?
Heated seats are very heavy on current

I do wonder if the alternator output is enough on cars that do a lot of short journeys in poor weather?
Often the output at idle - such as when sat in traffic is only perhaps 50% of the full output - and say a 75 Amp alternator might only average 40 amps on a journey with a lot of idling. On a 10 minute journey if the electrical load is say 30 Amps (not unreasonable with headlights, heated rear window, heated mirrors, heater fan and a/c clutch let alone heated seats), the the battery will only get charged at 10 amps for 10 minutes. Is this enough to cover the cold start etc?

7th January 2007, 14:55	#13 (permalink)
3rd Honda Triangular Exhaust Join Date: 24th July 2006 Location: Tewkesbury Posts: 414 Thanks: 0 Thanked 5 Times in 5 Posts iTrader: (0)	Does anybody know what the alternator output is on the Civic (I assume CTDI and VTEC will be the same)? The reason I ask is that there is a huge electrical demand: Pre-heaters use many amps, albeit for only a few seconds Diesel starter is a very heavy load Heated rear windows and mirrors come on automatically Headlights, etc Heater on Auto runs the fan quite hard, and I assume the a/c compressor clutch There has been rumoured to be an electric heater to assist quick warm up on the diesels? Heated seats are very heavy on current I do wonder if the alternator output is enough on cars that do a lot of short journeys in poor weather? Often the output at idle - such as when sat in traffic is only perhaps 50% of the full output - and say a 75 Amp alternator might only average 40 amps on a journey with a lot of idling. On a 10 minute journey if the electrical load is say 30 Amps (not unreasonable with headlights, heated rear window, heated mirrors, heater fan and a/c clutch let alone heated seats), the the battery will only get charged at 10 amps for 10 minutes. Is this enough to cover the cold start etc? Last edited by 3rd Honda; 7th January 2007 at 15:00.